How serious is this DTC?

A stored P2057 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 P2057 trouble code may include:

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

What are some common causes of the code?

Causes of this code may include:

• Faulty reductant injection valve
• Open or shorted circuits in the reductant injection valve control
• Insufficient DEF in the tank
• Faulty SCR controller/PCM or programming error

What are the troubleshooting steps for P2057?

You will need access to a diagnostic scanner, a digital volt/ohmmeter (DVOM), and a source of vehicle-specific diagnostic information to diagnose a P2057 code.

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

You’ll want to start your diagnosis with a visual inspection of the reductant heater system harnesses and connectors. Burned or damaged wiring and/or connectors should be repaired or replaced before continuing.

Proceed by hooking up the scanner to the vehicle’s diagnostic connector and retrieving all stored codes and relevant freeze frame data. Note this information before clearing the codes and test drive the vehicle until the PCM enters readiness mode or the code resets.

The code is intermittent and may be much more difficult to diagnose (for the time being) if the PCM enters readiness mode. 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 resets, consult your vehicle information source for diagnostic flowcharts, connector pinout diagrams, connector face views, as well as component testing procedures and specifications. This information will be needed to complete the next step of your diagnosis.

Use the DVOM to test the SCR control system’s power supply. Test fuses with the circuit loaded to avoid misdiagnosis. If the proper power and ground circuits are detected, use the scanner to activate the reductant injector valve (solenoid) and test the output control circuit voltage. If the voltage is insufficient, suspect that the controller is faulty or has encountered a programming error.

If the voltage output circuit is within parameters, use the DVOM to test the reductant injection valve in question. If the valve does not meet manufacturer specifications, suspect that it has failed.

The reductant injection valve is actually a solenoid injector that sprays reductant fluid into the exhaust

⚠️ Critical Severity

• Complete SCR system deactivation → Pollutant emissions exceeding standards

• Risk of SCR catalyst deterioration (high cost)

• Engine power limitation (limp mode)

• Illegal to drive (imminent technical inspection failure)

---

🚨 Symptoms

• Excessive black smoke during acceleration

• Noticeable power loss (especially on inclines)

• Antipollution fault warning light illuminated (⛽ + 💨)

• Engine overheating (inappropriate gear ratios)

• Related fault code(s): P20BD, P2201

---

🔧 Common Causes (Probability Order)

---

🔍 Diagnostic Procedure

Step 1: Initial Checks (15 min)

1. DEF Level:

   • Refill if < ⅓ (⚠️ use ISO 22241 certified DEF).

2. DEF Condition:

   • Drop on hot surface → must evaporate without residue.

3. Visual Inspection:

   • Injector (under exhaust line): leaks, white crystals.

   • Connector: green corrosion (critical point on RAM 1500, VW TDI).

Step 2: Electrical Tests

Step 3: Advanced Diagnostics

• Use a scanner capable of forcing the injector:

  • Listen for injector click.

  • Check DEF flow rate (PID data).

• Check DEF system pressure (failed pump?).

---

💰 Repairs & Costs

⏱️ Service time: 1h (diagnostics) + 2h to 4h (repair).

---

⚠️ Consequences of Ignoring

• SCR catalyst blockage (replacement > 2000 €).

• Legal penalties:

  • Fine up to 750 € (EU)

  • Vehicle immobilization (technical inspection).

• Turbo overheating (excessive exhaust temperatures).

---

🔧 Pro Tips

1. Winter emergency:

   • Use DEF with antifreeze additive (e.g., AdBlue Arctic).

2. Quick test:

   • Disconnect injector → If code changes from P2058 to P2059, injector is faulty.

3. Reset:

   • After repair: reset DEF counter via scanner + forced regeneration cycle.

4. Manufacturer references:

   • Bosch injector 0 986 455 008 (VAG)

   • Delphi SCR module 104843-11 (Ford)

5. Known TSBs:

   • RAM #18-047-20: Software update for false P2058 on 2019 EcoDiesel.

📊 Workshop Statistics: 60% of P2058 resolved by injector replacement + DEF circuit purge.

---

Conclusion:
P2058 is a major antipollution failure. Recommended procedure:

1. Check DEF level/quality

2. Test injector resistance + PCM voltage

3. Replace injector if faulty → Purge the circuit
   Immediate intervention required: A deactivated SCR system can damage DPF and turbo in under 1000 km!

How serious is this DTC?

A stored P2059 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 P2059 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 air pressure sensor
• Faulty reductant injection air pump
• 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 P2059?

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 P2059 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 air pump control circuits, components, and sensors according to manufacturer specifications. Circuit failure codes can be caused by faulty components or sensors. Sensors and components that don’t test within maximum allowable parameters should be considered defective.

Step 2

If reductant air pressure is within specifications, the P0259 code persists, and all preliminary circuits, components, and sensors are 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 air pump control circuit codes are often attributed to internally leaking supply pumps

Severity and Diagnosis of Code P205A

How Severe Is Code P205A?

Diagnostic code P205A is considered severe and should be addressed immediately. It can disable the selective catalytic reduction (SCR) system and cause damage to the catalyst if not resolved promptly.

Symptoms of Code P205A

The most common symptoms associated with code P205A include:

• Reduced fuel efficiency
• Excessive black smoke from the exhaust
• Decreased engine performance
• Appearance of other SCR system-related codes

Possible Causes of Code P205A

This code can be triggered by several factors, including:

• A faulty reductant tank temperature sensor
• Open or shorted circuits in the temperature sensor system
• A defective SCR control module or PCM, or a programming error

Troubleshooting Code P205A

Diagnosing code P205A requires:

• A diagnostic scanner
• A digital volt/ohmmeter (DVOM)
• A vehicle-specific diagnostic information source

Step 1: Checking TSBs and Reading Codes

Consult the technical service bulletins (TSBs) for your vehicle model. Use a diagnostic scanner to retrieve stored codes and freeze frame data. Record this information before clearing the codes and perform a road test to see if the code resets.

Step 2: Testing the Reductant Temperature Sensor

Using a DVOM, test the temperature sensor according to the manufacturer’s specifications. Any sensor that does not meet the required parameters should be replaced.

Step 3: Inspecting Electrical Circuits

If the reductant temperature meets specifications and the code persists, test the input and output signal circuits between the sensor and the SCR/PCM controller. Before using the DVOM, disconnect all controllers to avoid damaging the system.

Conclusion

Error codes related to the reductant temperature sensor are often caused by a faulty sensor or connection issue. Thorough diagnosis helps effectively identify and repair the malfunction to ensure proper SCR system operation and prevent more severe catalyst damage.

How serious is this DTC?

A stored P205B 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 P205B 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 tank temperature sensor
• Open or shorted circuits in the reductant tank temperature sensor system
• Faulty SCR controller/PCM or programming error

What are the P205B troubleshooting steps?

A diagnostic scanner, digital volt/ohmmeter (DVOM), and vehicle-specific diagnostic information source will be needed to diagnose a P205B 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 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 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 P205B 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 severe is this DTC?

A stored P205C code should be considered severe 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 P205C 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 tank temperature sensor
• Open or shorted circuits in the reductant tank temperature sensor system
• Faulty SCR controller/PCM or programming error

What are the troubleshooting steps for P205C?

A diagnostic scanner, digital volt/ohmmeter (DVOM), and vehicle-specific diagnostic information source will be needed to diagnose a P205C 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 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 temperature sensor according to manufacturer specifications. Components that don’t test within allowed parameters should be considered faulty.

Step 2

If the actual reductant temperature is within specifications, the P205C 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 P205D code should be considered serious and addressed as soon as possible. The SCR system may 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 P205D 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 tank temperature sensor
• Open or shorted circuits in the reductant tank temperature sensor system
• Faulty SCR controller/PCM or programming error

What Are the P205D Troubleshooting Steps?

A diagnostic scanner, digital volt/ohmmeter (DVOM), and vehicle-specific diagnostic information source will be needed to diagnose a P205D 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 test outside the allowable parameters should be considered faulty.

Step 2

If the actual reductant temperature is within specifications, the P205D 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 P205E code should be considered serious and addressed as soon as possible. The SCR system may 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 P205E 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 tank temperature sensor
• Open or shorted circuits in the reductant tank temperature sensor system
• Faulty SCR controller/PCM or programming error

What Are the P205E Troubleshooting Steps?

A diagnostic scanner, digital volt/ohmmeter (DVOM), and vehicle-specific diagnostic information source will be needed to diagnose a P205E 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 test outside the allowable parameters should be considered defective.

Step 2

If the actual reductant temperature is within specifications, the P205E 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 Severe Is This DTC?

A stored P205F code should be considered severe and addressed as quickly as possible. The SCR system may be disabled because of this. Catalyst damage can occur if the conditions that contributed to the code being stored are not rectified in a timely manner.

What Are Some Symptoms of the Code?

Symptoms of a P205F 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 pressure sensor
• Faulty reductant system injector
• Incorrect or inadequate DEF
• Open or shorted circuits in the reductant system
• Faulty SCR controller/PCM or programming error

What Are the P205F Troubleshooting Steps?

A diagnostic scanner, digital volt/ohmmeter (DVOM), and vehicle-specific diagnostic information source will be needed to diagnose a P205F 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 pressure sensor according to manufacturer specifications. Components that do not test within allowed parameters should be considered faulty.

Step 2

If the actual reductant system pressure meets specifications, the P205F code persists, and the sensors are operational, use the DVOM to test the input and output signal circuits between the SCR system sensors and the PCM/SCR controller. Disconnect all controllers before using the DVOM for testing.

Reductant system performance codes are often attributed to low or incorrect DEF

How serious is this DTC?

A stored P2060 code should be considered serious and addressed as soon as possible. The SCR system may 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 P2060 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
• Faulty reductant injection air pump
• 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 P2060?

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 P2060 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 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 air pump control circuits, components, and sensors according to manufacturer specifications. Circuit failure codes can be caused by faulty components or sensors. Sensors and components that do not test within maximum allowable parameters should be considered defective.

Step 2

If reductant air pressure is within specifications, the P0259 code persists, and all preliminary circuits, components, and sensors are 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 air pump control circuit codes are often attributed to internally leaking supply pumps