How serious is this DTC?

I would say it’s a fairly minor code considering the possibilities. We’re essentially talking about a fault in a system that monitors what happens after it has already been burned and used. That said, most state/country emission standards are quite strict, so it’s a good idea to address it before it causes more harm to your vehicle, not to mention the atmosphere!

What are some symptoms of the code?

Symptoms of a P203C diagnostic code may include:

• Incorrect DEF (Diesel Exhaust Fluid) level reading
• Out-of-spec exhaust emissions
• Check Engine Light (CEL) illuminated
• Excessive smoke
• “Low” or other DEF warning on the instrument cluster

What are some common causes of the code?

Causes of this P203C engine code may include:

• Faulty reductant level sensor
• Incorrect fluid in the DEF storage tank
• Electrical short circuit

What are the diagnostic and troubleshooting steps for P203C?

The first step in the troubleshooting process for any malfunction is to check Technical Service Bulletins (TSBs) for known issues with the specific vehicle.

Advanced diagnostic steps become very vehicle-specific and may require appropriate advanced equipment and knowledge to operate accurately. We include the basic steps below but refer to a repair guide specific to the year/make/model/drivetrain for steps tailored to your vehicle.

Basic Step #1
Ensure to completely clear all active codes and test-drive the vehicle before diagnosing present codes. This will clear any codes that were left active after repairs or other intermittent and minor codes. After a road test, re-scan the vehicle and proceed with diagnosing only the active codes.

Basic Step #2
I’m sure after owning your vehicle for a significant period, you know where the DEF (Diesel Exhaust Fluid) storage tank is located. If not, I’ve seen them located in the trunk and also under the vehicle. That said, the storage tank’s fill neck should be easily accessible, either in the trunk or next to your fuel fill neck. Make sure to distinguish it first and foremost to avoid putting unwanted fluid in unwanted places. If you can check your level mechanically with a dipstick, go ahead and do so. Some vehicles, on the other hand, have no way to check the DEF level other than aiming a flashlight into the hole to visually see if there’s DEF inside. In any case, you’ll want to top off the fluid, especially if P203F is present.

Basic Step #3
Depending on the capabilities of your OBD2 code reader/scan tool, you might be able to monitor the sensor electronically with it. Especially if you know the storage tank is full of DEF and the reading demonstrates otherwise. If that’s the case, the reductant level sensor is likely faulty and will need replacement. This can be tricky given that it will be mounted on the tank. Be sure to catch any DEF that comes out when replacing the sensor.

Basic Step #4
If you can easily access the reductant level sensor connector, ensure it’s making a good electrical connection. Also, it’s always wise to refer to the manufacturer’s service data to obtain specific values and level sensor testing procedures to confirm it’s faulty before replacing it. You’ll likely need a multimeter for this as there might be resistance tests involved. Compare the actual present values to the desired ones provided by the manufacturer. If the values are out of spec, the sensor will need to be replaced.

NOTE: Always follow the manufacturer’s guidelines for when to disconnect your battery, safety precautions, etc.

Basic Step #5
Inspect the reductant level sensor wiring harness for any damage or chafed wires; this can cause erratic values to be sent to the ECM and lead you to replace the sensor when it wasn’t necessary. Any exposed wire or corrosion should be repaired before continuing. Ensure the harness is securely fastened and away from any moving parts.

This article is strictly for informational purposes only, and the technical data and service bulletins for your specific vehicle should always take precedence.

How Severe Is This DTC?

I would say it’s a fairly minor code considering the possibilities. We’re essentially talking about a fault in a system that monitors what happens after it has already been burned and used. That said, most state/country emission standards are quite strict, so it’s a good idea to address it before it causes more harm to your vehicle, not to mention the atmosphere!

What Are Some of the Symptoms of the Code?

Symptoms of a P203D diagnostic code may include:

• Incorrect DEF (Diesel Exhaust Fluid) level reading
• Exhaust emissions out of specifications
• Check Engine Light (CEL) illuminated
• Excessive smoke
• “Low” or other DEF warning on the instrument cluster

What Are Some Common Causes of the Code?

Causes of this P203D engine code may include:

• Faulty reductant level sensor
• Incorrect fluid in the DEF storage tank
• Electrical short circuit

What Are the Diagnostic and Troubleshooting Steps for P203D?

The first step in the troubleshooting process for any malfunction is to check Technical Service Bulletins (TSBs) for known issues with the specific vehicle.

Advanced diagnostic steps become very vehicle-specific and may require appropriate advanced equipment and knowledge to operate accurately. We include the basic steps below but refer to a repair guide specific to the year/make/model/drivetrain for steps tailored to your vehicle.

Basic Step #1
Ensure to fully clear all active codes and test-drive the vehicle before diagnosing present codes. This will clear any codes that were left active after repairs or other intermittent and minor codes. After a road test, re-scan the vehicle and proceed with diagnosing only the active codes.

Basic Step #2
I’m sure after owning your vehicle for a significant period, you know where the DEF (Diesel Exhaust Fluid) storage tank is located. If not, I’ve seen them located in the trunk and also under the vehicle. That said, the storage tank’s fill neck should be easily accessible, either in the trunk or next to your fuel fill neck. Make sure to distinguish it first and foremost to avoid putting unwanted fluid in unwanted places. If you can check your level mechanically with a dipstick, go ahead and do so. Some vehicles, on the other hand, have no way to check the DEF level other than aiming a flashlight into the hole to visually see if there’s DEF inside. In any case, you’ll want to top off the fluid, especially if P203F is present.

Basic Step #3
Depending on the capabilities of your OBD2 code reader/scan tool, you may be able to monitor the sensor electronically with it. Especially if you know the storage tank is full of DEF and the reading shows otherwise. If that’s the case, the reductant level sensor is likely faulty and will need to be replaced. This can be tricky since it will be mounted on the tank. Be sure to catch any DEF that comes out when replacing the sensor.

Basic Step #4
If you can easily access the reductant level sensor connector, ensure it’s making a good electrical connection. Also, it’s always wise to refer to the manufacturer’s service data for specific values and level sensor testing procedures to confirm it’s faulty before replacing it. You’ll likely need a multimeter for this as there may be resistance tests involved. Compare the actual values present to the desired ones provided by the manufacturer. If the values are out of specifications, the sensor will need to be replaced.

NOTE: Always follow the manufacturer’s guidelines for when to disconnect your battery, safety precautions, etc.

Basic Step #5
Inspect the reductant level sensor wiring harness for any damage or chafed wires; this can cause erratic values to be sent to the ECM and lead you to replace the sensor when it wasn’t necessary. Any exposed wires or corrosion should be repaired before continuing. Ensure the harness is securely fastened and away from any moving parts.

This article is strictly for informational purposes only, and technical data and service bulletins for your specific vehicle should always take precedence.

How serious is this DTC?

I would say it’s a fairly minor code considering the possibilities. We’re essentially talking about a fault in a system that monitors what happens after it has already been burned and used. That said, most state/country emission standards are quite strict, so it’s a good idea to address it before it causes more harm to your vehicle, not to mention the atmosphere!

What are some of the symptoms of the code?

Symptoms of a P203E diagnostic code may include:

• Incorrect DEF (Diesel Exhaust Fluid) level reading
• Exhaust emissions out of specifications
• Check Engine Light (CEL) illuminated
• Excessive smoke
• “Low” or other DEF warning on the instrument cluster

What are some common causes of the code?

Causes of this P203E engine code may include:

• Faulty reductant level sensor
• Incorrect fluid in the DEF storage tank
• Broken wire or harness causing intermittent electrical connections
• Electrical short circuit

What are the diagnostic and troubleshooting steps for P203E?

The first step in the troubleshooting process for any malfunction is to check Technical Service Bulletins (TSBs) for known issues with the specific vehicle.

Advanced diagnostic steps become very vehicle-specific and may require the appropriate advanced equipment and knowledge to operate accurately. We include the basic steps below but refer to a repair guide specific to the year/make/model/drivetrain for steps tailored to your vehicle.

Basic Step #1
Ensure to completely clear all active codes and test drive the vehicle before diagnosing the present codes. This will clear any codes that were left active after repairs or other intermittent and less significant codes. After a road test, re-scan the vehicle and proceed with diagnosing only the active codes.

Basic Step #2
I’m sure after owning your vehicle for a significant period, you know where the DEF (Diesel Exhaust Fluid) storage tank is located. If not, I’ve seen them located in the trunk and also under the vehicle. That said, the storage tank’s fill neck should be easily accessible, either in the trunk or next to your fuel fill neck. Make sure to distinguish it first and foremost to avoid putting unwanted fluid in unwanted places. If you can check your level mechanically with a dipstick, go ahead and do so. Some vehicles, on the other hand, have no way to check the DEF level other than aiming a flashlight into the hole to visually see if there’s DEF inside. In any case, you’ll want to top off the fluid, especially if P203F is present.

Basic Step #3
Depending on your OBD2 code reader/scan tool’s capabilities, you may be able to monitor the sensor electronically with it. Especially if you know the storage tank is full of DEF and the reading demonstrates otherwise. If that’s the case, the reductant level sensor is likely faulty and will need replacement. This can be tricky given that it will be mounted on the tank. Be sure to catch any DEF that comes out when replacing the sensor.

Basic Step #4
If you can easily access the reductant level sensor connector, ensure it’s making a good electrical connection. Also, it’s always wise to refer to the manufacturer’s service data for specific values and level sensor testing procedures to confirm it’s faulty before replacing it. You’ll likely need a multimeter for this as there might be resistance tests involved. Compare the actual present values to the desired ones provided by the manufacturer. If the values are out of specification, the sensor will need to be replaced.

NOTE: Always follow the manufacturer’s guidelines for when to disconnect your battery, safety precautions, etc.

Basic Step #5
Inspect the reductant level sensor wiring harness for any damage or chafed wires; this can cause erratic values to be sent to the ECM and lead you to replace the sensor when it wasn’t necessary. Any exposed wire or corrosion should be repaired before continuing. Ensure the harness is securely fastened and away from all moving parts.

This article is strictly for informational purposes only, and the technical data and service bulletins for your specific vehicle should always take precedence.

How serious is this DTC?

I would say it’s a fairly minor code considering the possibilities. We’re essentially talking about a fault in a system that monitors what happens after it has already been burned and used. That said, most state/country emission standards are quite strict, so it’s a good idea to address it before it causes more harm to your vehicle, not to mention the atmosphere!

What are some of the symptoms of the code?

Symptoms of a P203F diagnostic code may include:

• Incorrect DEF (Diesel Exhaust Fluid) level reading
• Exhaust emissions out of specifications
• Check Engine Light (CEL) illuminated
• Excessive smoke
• “Low” or other DEF warning on the instrument cluster

What are some common causes of the code?

Causes of this P203F engine code may include:

• Faulty reductant level sensor
• Incorrect fluid in the DEF storage tank
• DEF level is low and needs to be topped up
• Electrical short circuit

What are the diagnostic and troubleshooting steps for P203F?

The first step in the troubleshooting process for any malfunction is to check Technical Service Bulletins (TSBs) for known issues with the specific vehicle.

Advanced diagnostic steps become very vehicle-specific and may require the appropriate advanced equipment and knowledge to operate accurately. We include the basic steps below but refer to a repair guide specific to the year/make/model/drivetrain for steps specific to your vehicle.

Basic Step #1
Ensure to completely clear all active codes and test drive the vehicle before diagnosing present codes. This will clear any codes that were left active after repairs or other intermittent and less significant codes. After a road test, re-scan the vehicle and proceed with diagnosing only the active codes.

Basic Step #2
I’m sure after owning your vehicle for a significant period, you know where the DEF (Diesel Exhaust Fluid) storage tank is located. If not, I’ve seen them located in the trunk and also under the vehicle. That said, the storage tank’s fill neck should be easily accessible, either in the trunk or next to your fuel fill neck. Make sure to distinguish it first and foremost to avoid putting unwanted fluid in unwanted places. If you can check your level mechanically with a dipstick, go ahead and do so. Some vehicles, on the other hand, have no way to check the DEF level other than shining a flashlight into the hole to visually see if there’s DEF inside. In any case, you’ll want to top up the fluid, especially if P203F is present.

Basic Step #3
Depending on your OBD2 code reader/scan tool’s capabilities, you might be able to monitor the sensor electronically with it. Especially if you know the storage tank is full of DEF and the reading demonstrates otherwise. If this is the case, the reductant level sensor is likely faulty and will need to be replaced. This can be tricky given that it will be mounted on the tank. Be sure to catch any DEF that comes out when replacing the sensor.

Basic Step #4
If you can easily access the reductant level sensor connector, ensure it is making a good electrical connection. Also, it’s always wise to refer to the manufacturer’s service data to obtain specific values and sensor level testing procedures to ensure it is faulty before replacing it. You will likely need a multimeter for this as there might be resistance tests involved. Compare the actual present values to the desired ones provided by the manufacturer. If the values are out of specification, the sensor will need to be replaced.

NOTE: Always follow the manufacturer’s guidelines for when to disconnect your battery, safety precautions, etc.

Basic Step #5
Inspect the reductant level sensor wiring harness for any damage or chafed wires; this can cause erratic values to be sent to the ECM and lead you to replace the sensor when it wasn’t necessary. Any exposed wire or corrosion should be repaired before proceeding. Ensure the harness is securely fastened and away from any moving parts.

This article is strictly for informational purposes only, and the technical data and service bulletins for your specific vehicle should always take precedence.

Understanding the BMW P1443 Diagnostic Trouble Code

The P1443 diagnostic trouble code is a manufacturer-specific code that pertains exclusively to BMW vehicles and their sophisticated emission control systems. When this code appears, it indicates a malfunction within the secondary air injection system, specifically related to the “Combustion Air System, Bank 2.” This system is critical for reducing harmful emissions during your BMW’s cold start operation, helping the catalytic converter reach its optimal operating temperature more quickly.

What Does the P1443 Code Specifically Mean?

P1443 signifies that the BMW’s Engine Control Module (DME) has detected an insufficient airflow or incorrect pressure in the secondary air injection system for Bank 2 of the engine. The system is designed to inject fresh air into the exhaust stream immediately after a cold start, promoting more complete combustion of unburned hydrocarbons before they exit the exhaust system.

How the Secondary Air Injection System Operates

BMW’s secondary air injection system consists of several key components working in harmony:

• Electric air pump that supplies fresh air
• Air control valves that regulate airflow
• Vacuum-operated switching valves
• Pressure sensors and temperature sensors
• Complex network of hoses and pipes

The system activates for approximately 90-120 seconds after a cold engine start, injecting additional oxygen into the exhaust ports to help burn off excess fuel and reduce cold-start emissions.

Common Symptoms of P1443 in BMW Vehicles

Recognizing the symptoms associated with P1443 is crucial for timely diagnosis and repair. While some symptoms may be subtle, others can significantly impact your BMW’s performance and emissions compliance.

Immediate Warning Signs and Indicators

When P1443 is stored in your BMW’s DME, you’ll typically experience:

• Illuminated check engine light on your dashboard
• Possible reduced engine performance or limp mode
• Failed emissions test during vehicle inspection
• Rough idle during cold starts in some cases
• Abnormal sounds from the engine bay during startup

Long-Term Consequences of Ignoring P1443

While your BMW may remain drivable with a P1443 code, prolonged neglect can lead to:

• Increased hydrocarbon emissions contributing to environmental pollution
• Potential damage to the catalytic converter over time
• Reduced fuel efficiency due to compromised emission controls
• Progression to more severe drivability issues
• Possible failure of other emission-related components

Comprehensive Diagnostic Procedure for P1443

Proper diagnosis of P1443 requires a systematic approach to identify the root cause. This procedure should be performed with the appropriate diagnostic tools and technical knowledge.

Initial Visual Inspection and Preliminary Checks

Begin with a thorough visual examination of the secondary air system components:

• Inspect all vacuum hoses for cracks, brittleness, or disconnections
• Check electrical connections to the air pump and control valves
• Examine the air pump for physical damage or corrosion
• Verify the integrity of air pipes and check valves
• Look for any obvious obstructions in the air intake path

Advanced Electrical and Functional Testing

After completing visual inspection, proceed with comprehensive testing:

• Use a BMW-specific diagnostic scanner to monitor live data from the secondary air system
• Test the air pump operation by activating it directly through the diagnostic interface
• Check vacuum supply to the control valves using a vacuum gauge
• Measure voltage and ground signals at the air pump connector
• Perform pressure tests on the air delivery system to identify restrictions

Primary Causes and Repair Solutions for P1443

Understanding the common causes of P1443 will help you address the issue effectively. The problem can range from simple fixes to more complex component replacements.

Most Frequent Culprits Behind P1443

The P1443 code typically stems from one of these common issues:

• Failed secondary air pump due to wear or electrical failure
• Faulty or stuck secondary air control valve
• Cracked or leaking vacuum hoses in the control circuit
• Blocked air injection pipes or check valves
• Electrical issues including broken wires, corroded connectors, or blown fuses
• Problems with the DME control module or its programming

Step-by-Step Repair Guidelines

Depending on your diagnostic findings, follow these repair procedures:

• Replace the secondary air pump if it fails to operate or shows low output
• Install new control valves if they’re stuck open or closed
• Replace all deteriorated vacuum lines and ensure proper routing
• Clean or replace blocked air pipes and malfunctioning check valves
• Repair any damaged wiring and clean electrical connections
• Update DME software if recommended by technical service bulletins

Preventive Maintenance and System Longevity

Regular maintenance can prevent recurrence of P1443 and ensure your BMW’s emission systems operate optimally for years to come.

Essential Maintenance Practices

Implement these practices to maintain your secondary air injection system:

• Follow BMW’s recommended maintenance schedule strictly
• Regularly inspect emission system components during routine service
• Address any check engine lights promptly to prevent secondary damage
• Use quality replacement parts that meet BMW specifications
• Keep the engine compartment clean to prevent debris accumulation

When to Seek Professional Assistance

While some P1443 issues can be addressed by knowledgeable DIY enthusiasts, complex scenarios require professional expertise:

• When the root cause isn’t apparent after basic diagnostics
• If the DME requires programming or coding after component replacement
• When dealing with intermittent electrical faults
• If multiple emission-related codes are present simultaneously
• When specialized diagnostic equipment is necessary for accurate diagnosis

Successfully diagnosing and repairing P1443 not only resolves your check engine light but also ensures your BMW continues to meet emission standards while maintaining optimal performance. Always clear the fault codes after repairs and verify the fix by performing a test drive and system readiness check.

How serious is this DTC?

A stored P2040 code should be considered serious and addressed as soon as possible. The SCR system could be disabled because of this. Catalyst damage could occur if the conditions that contributed to the code being stored are not corrected in a timely manner.

What are some of the symptoms of the code?

Symptoms of a P2040 trouble code may include:

• Reduced fuel efficiency
• Excessive black smoke from the vehicle’s exhaust
• Decreased engine performance
• Other SCR-related codes

What are some common causes of the code?

Causes of this code may include:

• Faulty reductant air pressure sensor (A)
• Open or shorted circuits in the reductant injection air pressure sensor system
• Faulty SCR controller/PCM or programming error

What are the troubleshooting steps for P2040?

Ensure the reductant supply/regeneration system is not losing pressure (internally or externally). Activate the pump to create pressure and inspect the system for external leaks. Use a fuel pressure tester to manually monitor reductant system pressure. Check the supply pump and injector for leaks. If leaks are discovered (internal or external), they must be repaired before continuing diagnosis.

A diagnostic scanner, digital volt/ohmmeter (DVOM), and vehicle-specific diagnostic information source will be needed to diagnose a P2040 code.

You can use your vehicle information source to locate a technical service bulletin (TSB) that matches the vehicle’s year, make, and model; as well as engine size, stored codes, and presented symptoms. If you find one, it might provide helpful diagnostic information.

Use the scanner (connected to the vehicle’s diagnostic connector) to retrieve all stored codes and relevant freeze frame data. It’s a good idea to record this information before clearing the codes, then test drive the vehicle until the PCM enters readiness mode or the code resets.

If the PCM enters readiness mode at that point, the code is intermittent and may be much more difficult to diagnose. If this is the case, the conditions that contributed to the code being stored may need to worsen before an accurate diagnosis can be made.

If the code immediately resets, the next step in your diagnosis will require you to search your vehicle information source for diagnostic flowcharts, connector pinout diagrams, connector face views, and component testing procedures/specifications.

Step 1
Use the DVOM to test the reductant injection system pressure sensors according to manufacturer specifications. Components that don’t test within allowable parameters should be considered faulty.

Step 2
If reductant injection pressure is within specifications, the P2040 code persists, and the sensor in question is operational, use the DVOM to test the input and output signal circuits between the sensors and the PCM/SCR controller. Disconnect all controllers before using the DVOM for testing.

Reductant injector sensor codes are often attributed to internally leaking supply pumps

How serious is this DTC?

A stored P2041 code should be considered serious and addressed as soon as possible. The SCR system could be disabled because of this. Catalyst damage could occur if the conditions that contributed to the code being stored are not corrected in a timely manner.

What are some of the symptoms of the code?

Symptoms of a P2041 fault code may include:

• Reduced fuel efficiency
• Excessive black smoke from the vehicle’s exhaust
• Decreased engine performance
• Other SCR-related codes

What are some common causes of the code?

Causes of this code may include:

• Faulty reductant air pressure sensor (A)
• Open or shorted circuits in the reductant injection air pressure sensor system
• Faulty SCR controller/PCM or programming error

What are the troubleshooting steps for P2041?

Ensure the reductant supply/regeneration system is not losing pressure (internally or externally). Activate the pump to create pressure and inspect the system for external leaks. Use a fuel pressure tester to manually monitor reductant system pressure. Check the supply pump and injector for leaks. If leaks are discovered (internal or external), they must be repaired before continuing diagnosis.

A diagnostic scanner, digital volt/ohmmeter (DVOM), and vehicle-specific diagnostic information source will be required to diagnose a P2041 code.

You can use your vehicle information source to locate a technical service bulletin (TSB) that matches the vehicle’s year, make, and model; as well as engine size, stored codes, and presented symptoms. If you find one, it might provide helpful diagnostic information.

Use the scanner (connected to the vehicle’s diagnostic connector) to retrieve all stored codes and relevant freeze frame data. It’s a good idea to record this information before clearing the codes, then test drive the vehicle until the PCM enters readiness mode or the code resets.

If the PCM enters readiness mode at this point, the code is intermittent and may be much more difficult to diagnose. If this is the case, the conditions that contributed to the code being stored may need to worsen before an accurate diagnosis can be made.

If the code immediately resets, the next step in your diagnosis will require you to search your vehicle information source for diagnostic flowcharts, connector pinout diagrams, connector face views, and component testing procedures/specifications.

Step 1

Use the DVOM to test the reductant injection system pressure sensors according to manufacturer specifications. Components that don’t test within allowable parameters should be considered defective.

Step 2

If reductant injection pressure meets specifications, the P2041 code persists, and the sensor in question is operational, use the DVOM to test the input and output signal circuits between the sensors and the PCM/SCR controller. Disconnect all controllers before using the DVOM for testing.

Reductant injector sensor codes are often attributed to internally leaking supply pumps

How serious is this DTC?

A stored P2042 code should be considered serious and addressed as quickly as possible. The SCR system could be disabled because of this. Catalyst damage could occur if the conditions that contributed to the code being stored are not corrected in a timely manner.

What are some of the symptoms of the code?

Symptoms of a P2042 trouble code may include:

• Reduced fuel efficiency
• Excessive black smoke from vehicle exhaust
• Decreased engine performance
• Other SCR-related codes

What are some common causes of the code?

Causes

of this code may include:

• Faulty reductant temperature sensor
• Open or shorted circuits in the reductant temperature sensor system
• Faulty SCR controller/PCM or programming error

What are the troubleshooting steps for P2042?

A diagnostic scanner, digital volt/ohmmeter (DVOM), and vehicle-specific diagnostic information source will be needed to diagnose a P2042 code.

You can use your vehicle information source to locate a technical service bulletin (TSB) that matches the vehicle’s year, make, and model; as well as engine size, stored codes, and presented symptoms. If you find one, it could provide helpful diagnostic information.

Use the scanner (connected to the vehicle’s diagnostic connector) to retrieve all stored codes and relevant freeze frame data. It’s a good idea to record this information before clearing the codes, then test the vehicle until the PCM enters readiness mode or the code resets.

If the PCM enters readiness mode at this point, the code is intermittent and may be much more difficult to diagnose. If this is the case, the conditions that contributed to the code being stored may need to worsen before an accurate diagnosis can be made.

If the code immediately resets, the next step in your diagnosis will require you to search your vehicle information source for diagnostic flowcharts, connector pinout diagrams, connector face views, and component testing procedures/specifications.

Step 1

Use the DVOM to test the reductant temperature sensor according to manufacturer specifications. Components that do not test within the allowed maximum parameters should be considered faulty.

Step 2

If the actual reductant temperature meets specifications, the P2042 code persists, and the sensor in question is operational, use the DVOM to test the input and output signal circuits between the temperature sensor and the PCM/SCR controller. Disconnect all controllers before using the DVOM for testing.

Reductant temperature sensor codes are typically attributed to a faulty or disconnected sensor

How serious is this DTC?

A stored P2043 code should be considered serious and addressed as quickly as possible. The SCR system could be disabled because of this. Catalyst damage could occur if the conditions that contributed to the code being stored are not corrected in a timely manner.

What are some of the symptoms of the code?

Symptoms of a P2043 trouble code may include:

• Reduced fuel efficiency
• Excessive black smoke from vehicle exhaust
• Decreased engine performance
• Other SCR-related codes

What are some common causes of the code?

Causes of this code may include:

• Faulty reductant temperature sensor
• Open or shorted circuits in the reductant temperature sensor system
• Faulty SCR controller/PCM or programming error

What are the troubleshooting steps for P2043?

A diagnostic scanner, digital volt/ohmmeter (DVOM), and vehicle-specific diagnostic information source will be needed to diagnose a P2043 code.

You can use your vehicle information source to locate a technical service bulletin (TSB) that matches the vehicle’s year, make, and model; as well as engine size, stored codes, and presented symptoms. If you find one, it could provide helpful diagnostic information.

Use the scanner (connected to the vehicle’s diagnostic connector) to retrieve all stored codes and relevant freeze frame data. It’s a good idea to record this information before clearing the codes, then test the vehicle until the PCM enters readiness mode or the code resets.

If the PCM enters readiness mode at this point, the code is intermittent and may be much more difficult to diagnose. If this is the case, the conditions that contributed to the code being stored may need to worsen before an accurate diagnosis can be made.

If the code immediately resets, the next step in your diagnosis will require you to search your vehicle information source for diagnostic flowcharts, connector pinout diagrams, connector face views, and component testing procedures/specifications.

Step 1

Use the DVOM to test the reductant temperature sensor according to manufacturer specifications. Components that test outside the allowable parameters should be considered faulty.

Step 2

If the actual reductant temperature is within specifications, the P2043 code persists, and the sensor in question is operational, use the DVOM to test the input and output signal circuits between the temperature sensor and the PCM/SCR controller. Disconnect all controllers before using the DVOM for testing.

Reductant temperature sensor codes are typically attributed to a faulty or disconnected sensor

How Serious Is This DTC?

A stored P2044 code should be considered serious and addressed as soon as possible. The SCR system could be disabled because of this. Catalyst damage may occur if the conditions that contributed to the code being stored are not corrected in a timely manner.

What Are Some of the Symptoms of the Code?

Symptoms of a P2044 trouble code may include:

• Reduced fuel efficiency
• Excessive black smoke from the vehicle’s exhaust
• Decreased engine performance
• Other SCR-related codes

What Are Some Common Causes of the Code?

Causes

of this code may include:

• Faulty reductant temperature sensor
• Open or shorted circuits in the reductant temperature sensor system
• Faulty SCR controller/PCM or programming error

What Are the P2044 Troubleshooting Steps?

A diagnostic scanner, digital volt/ohmmeter (DVOM), and vehicle-specific diagnostic information source will be needed to diagnose a P2044 code.

You can use your vehicle information source to locate a technical service bulletin (TSB) that matches the vehicle’s year, make, and model; as well as engine size, stored codes, and presented symptoms. If you find one, it may provide helpful diagnostic information.

Use the scanner (connected to the vehicle’s diagnostic connector) to retrieve all stored codes and relevant freeze frame data. It’s a good idea to record this information before clearing the codes, then test drive the vehicle until the PCM enters readiness mode or the code resets.

If the PCM enters readiness mode at that point, the code is intermittent and may be much more difficult to diagnose. If this is the case, the conditions that contributed to the code being stored may need to worsen before an accurate diagnosis can be made.

If the code immediately resets, the next step in your diagnosis will require you to search your vehicle information source for diagnostic flowcharts, connector pinout diagrams, connector face views, and component testing procedures/specifications.

Step 1

Use the DVOM to test the reductant temperature sensor according to manufacturer specifications. Components that do not test within allowable parameters should be considered faulty.

Step 2

If the actual reductant temperature is within specifications, the P2044 code persists, and the sensor in question is operational, use the DVOM to test the input and output signal circuits between the temperature sensor and the PCM/SCR controller. Disconnect all controllers before using the DVOM for testing.

Reductant temperature sensor codes are typically attributed to a faulty or disconnected sensor