P2192 – System Too Rich at Higher Load Level 1

Symptoms

Symptoms of a P2192 engine code may include:

Malfunction Indicator Light (MIL) illuminated
Lack of power
Occasional misfires
Poor fuel economy

Causes

Possible causes for this code definition include:

Faulty Air/Fuel Ratio Sensor or Oxygen Sensor (AFR/O2)
Faulty Mass Air Flow (MAF) Sensor
Rarely – Faulty Powertrain Control Module (PCM)

Diagnostic and Repair Procedures

A good starting point is always to check the Technical Service Bulletins (TSBs) for your specific vehicle. Your issue might be a known problem with a published fix from the manufacturer, which can save you time and money during diagnosis.

First, note if there are any other diagnostic trouble codes. If any are related to the fuel system, diagnose those first. Misdiagnosis is known to occur if this code is diagnosed before related fuel system codes have been thoroughly diagnosed and dismissed.

Once located, visually inspect the connectors and wiring. Look for chafing, rubbing, bare wires, burns, or melted plastic. Disconnect the connectors and carefully inspect the terminals (the metal parts) inside. Check if they appear corroded, burnt, or possibly greenish compared to the normal metallic color you’re used to seeing. You can get electrical contact cleaner at any auto parts store if terminal cleaning is needed. If not available, use 91% isopropyl alcohol and a soft plastic-bristled brush to clean them. Then let them air dry, get some dielectric silicone compound (the same type used for bulb sockets and spark plug wires), and apply it where the terminals make contact.

If you have a scan tool, clear the diagnostic codes from memory and see if this code returns. If it doesn’t, the connections were likely your problem.

If the code returns, we’ll need to test the voltage signal from the MAF sensor to the PCM. Monitor the MAF sensor voltage on your scan tool. If a scan tool isn’t available, test the signal from the MAF sensor with a Digital Volt-Ohm Meter (DVOM). With the sensor connected, attach the red voltmeter lead to the MAF sensor signal wire and the black voltmeter lead to ground. Start the engine and monitor the MAF sensor input. As engine RPM increases, the MAF sensor signal should increase. Check the manufacturer’s specifications, as there may be a chart indicating the voltage at a given RPM. If it fails this test, replace the MAF sensor and retest.

If the previous tests passed and the code is still present, monitor the Air/Fuel Ratio Sensor or Oxygen Sensor (AFR/O2). If it continuously indicates the engine is running rich, locate all possibilities that could cause a rich running condition. These include:

Fuel system, including fuel pressure regulator/fuel pressure
Fuel pressure sensor
Fuel injectors
Post-catalytic converter oxygen sensor
EVAP system, including the purge control valve
If the AFR/O2 sensor indicates the engine is running normally or even rich, a PCM may be suspected only after all other issues have been ruled out.

Again, it cannot be overemphasized that all other codes must be diagnosed before this one, as issues causing other codes to set may also cause this one.

P2193 – System Too Lean at Higher Load 2

Symptoms

Symptoms of a P2193 engine code may include:

Malfunction Indicator Lamp (MIL) illuminated
Lack of power
Occasional misfires
Poor fuel economy

Causes

Possible causes for this code being set include:

Faulty Air/Fuel Ratio Sensor/Oxygen Sensor (AFR/O2)
Faulty Mass Air Flow (MAF) Sensor
Rarely – Faulty Powertrain Control Module (PCM)

Diagnostic and Repair Procedures

First, note if there are any other Diagnostic Trouble Codes. If any are related to the fuel/fuel system, diagnose those first. Misdiagnosis is known to occur if a technician diagnoses this code before thoroughly diagnosing and clearing any fuel system-related codes. Ensure there are no intake or exhaust leaks. An intake leak, or vacuum leak, causes the engine to idle roughly. An exhaust leak makes the engine appear to be running lean to the AFR/O2 sensor.

Once located, visually inspect the connectors and wiring. Look for chafing, rubbing, bare wires, burns, or melted plastic. Disconnect the connectors and carefully inspect the terminals (the metal parts) inside. Check if they appear corroded, burnt, or possibly greenish compared to the normal metallic color you’re used to seeing. You can get electrical contact cleaner at any auto parts store if terminal cleaning is needed. If not available, find 91% isopropyl alcohol and a soft plastic-bristled brush to clean them. Then, let them air dry, get some dielectric silicone compound (the same type used for bulb sockets and spark plug wires), and apply a small amount where the terminals make contact.

If you have a scan tool, clear the Diagnostic Trouble Codes from memory and see if this code returns. If it doesn’t, the connections were likely your issue.

If the code returns, we’ll need to test the voltage signal from the MAF sensor to the PCM. Monitor the MAF sensor voltage on your scan tool. If a scan tool is not available, test the signal from the MAF sensor with a Digital Volt-Ohm Meter (DVOM). With the sensor connected, attach the red voltmeter lead to the MAF sensor signal wire and the black voltmeter lead to ground. Start the engine and monitor the MAF sensor input. As engine RPM increases, the MAF sensor signal should increase. Check the manufacturer’s specifications, as there may be a chart indicating the expected voltage at a given RPM. If it fails this test, replace the MAF sensor and retest.

If the previous tests pass and the code is still present, monitor the Air/Fuel Ratio Sensor/Oxygen Sensor (AFR/O2). If it continuously indicates the engine is running lean, locate all possible causes that could result in a lean condition. These include:

Intake or exhaust leaks
Fuel system, including fuel pressure regulator/fuel pressure
Fuel pressure sensor
Fuel injectors
Bank 2 O2 sensor after the catalytic converter
EVAP system, including the canister purge valve

If the AFR/O2 sensor indicates the engine is running normally or even rich, a faulty PCM may be suspected, but only after all other potential issues have been ruled out.

Again, it cannot be overemphasized that all other codes should be diagnosed before this one, as issues causing other codes to set can also trigger this code.

P2194 – System Too Rich at Higher Load 2

Symptoms

Symptoms of a P2194 engine code may include:

Malfunction Indicator Lamp (MIL) illuminated
Lack of power
Occasional misfires
Poor fuel economy

Causes

Possible causes for this code definition include:

Faulty Air/Fuel Ratio Sensor / Oxygen Sensor (AFR/O2)
Faulty Mass Air Flow (MAF) Sensor
Rarely – Faulty Powertrain Control Module (PCM)

Diagnostic and Repair Procedures

Once located, visually inspect the connectors and wiring. Look for chafing, rubbing, bare wires, burns, or melted plastic. Disconnect the connectors and carefully inspect the terminals (the metal parts) inside. Check if they appear corroded, burnt, or possibly greenish compared to the normal metallic color you’re used to seeing. You can get electrical contact cleaner at any auto parts store if terminal cleaning is needed. If not available, find 91% isopropyl alcohol and a soft plastic-bristled brush to clean them. Then, let them air dry, get some dielectric silicone compound (the same used for bulb sockets and spark plug wires), and apply it where the terminals make contact.

If you have a scan tool, clear the diagnostic codes from memory and see if this code returns. If it doesn’t, the connections were likely your issue.

If the previous tests passed and the code is still present, monitor the Bank 2 Air/Fuel Ratio Sensor / Oxygen Sensor (AFR/O2). If it continuously indicates the engine is running rich, identify all possible causes that could lead to a rich-running engine. These include:

Fuel system, including fuel pressure regulator / fuel pressure.
Fuel pressure sensor
Fuel injectors
Bank 2 post-catalytic converter O2 sensor
EVAP system, including the canister purge valve.
If the AFR/O2 sensor indicates the engine is running normally or even rich, a PCM may be suspected once all other issues have been ruled out.

Again, it cannot be overemphasized that all other codes should be diagnosed before this one, as issues causing other codes to set can also trigger this one.

P2195 O2 Sensor A/F Signal Biased/Stuck Lean (Bank 1 Sensor 1)

Symptoms

For this DTC, the malfunction indicator light (MIL) illuminates. There may be other symptoms.

Causes

Potential causes of a P2195 code include:

Malfunction of the oxygen sensor (O2) or A/F ratio sensor or sensor heater
Open or shorted O2 sensor circuit (wiring, harness)
Fuel pressure or fuel injector issue
Faulty PCM
Intake air leaks or engine vacuum leaks
Faulty fuel injector(s)
Fuel pressure too high or too low
PCV system leak/failure
Faulty A/F sensor relay
MAF sensor malfunction
ECT sensor malfunction
Fuel pressure too low
Fuel leak
Air intake in the air intake system

Diagnostic Steps and Possible Solutions

Use a scan tool to obtain sensor readings and monitor short-term and long-term fuel trim values and O2 sensor or air/fuel ratio readings. Also look at freeze frame data to see the conditions when the code was set. This should help determine if the AF O2 sensor is functioning properly. Compare with manufacturer values.

If you don’t have access to a scan tool, you can use a multimeter and probe the O2 sensor wiring connector terminals again. Check for shorts to ground, shorts to power, open circuits, etc. Compare specifications with manufacturer specifications.

Visually inspect the wiring and connectors leading to the sensor, look for loose connectors, rubbed/chafed wires, melted wires, etc. Repair if necessary.

Visually inspect the vacuum lines. You can also test for vacuum leaks using propane or carburetor cleaner along the hoses while the engine is running; if the RPM changes, you’ve probably found the leak. Be very careful if you do this, and have a fire extinguisher handy in case of problems. For example, on many Ford vehicles, the hose from the PCV to the throttle body can melt, causing P2195, P2197, P0171 and/or P0174 codes. If a vacuum leak proves to be the problem, it would be wise to replace all vacuum lines if they are aging, becoming brittle, etc.

Use a digital volt ohmmeter (DVOM) to check the proper operation of other mentioned sensors such as MAF, IAT.

Perform a fuel pressure test, check readings against manufacturer specifications.

If you are on a tight budget and only have an engine with more than one bank and the problem is only on one bank, you can swap the sensor from one bank to the other, clear the code and see if the code follows to the other bank. This would tell you that it is the sensor/heater itself that has failed.

Check for outstanding Technical Service Bulletins (TSBs) for your vehicle; in some cases, the PCM may be recalibrated to fix this issue (not a common solution though). TSBs might also call for sensor replacement.

When replacing oxygen/AF sensors, be sure to use high-quality sensors. In many cases, non-OEM sensors are of lower quality and will not function properly. We strongly recommend sticking with OEM brand replacements.

Saab P1443 Code: EVAP System Vent Control Circuit Explained

Understanding the Saab P1443 OBD-II Trouble Code

When your Saab’s check engine light illuminates and you retrieve the P1443 diagnostic trouble code, you’re dealing with a specific issue within your vehicle’s Evaporative Emission Control (EVAP) system. This code indicates a malfunction in the vent control circuit, which is crucial for preventing fuel vapors from escaping into the atmosphere. The P1443 code is manufacturer-specific to Saab vehicles, meaning its exact definition and diagnostic procedures are tailored to Saab’s engineering specifications.

The EVAP system in your Saab is designed to capture and store fuel vapors from the fuel tank, preventing them from being released into the environment. These vapors are later purged and burned in the engine during normal operation. The P1443 code specifically points to an electrical or functional problem within the circuit that controls the vent valve, which manages the flow of fresh air into the EVAP system and seals the system during pressure testing.

What Does the P1443 Code Mean in Saab Vehicles?

In technical terms, Diagnostic Trouble Code P1443 indicates “Evaporative Emission (EVAP) System Vent Control Circuit/Open.” This means the Engine Control Module (ECM) has detected an unexpected voltage level, resistance value, or operational behavior in the electrical circuit controlling the EVAP vent valve. The ECM continuously monitors this circuit, and when it receives signals outside predetermined parameters, it stores the P1443 code and illuminates the check engine light to alert the driver.

How the EVAP System Works in Saab Models

To properly understand and diagnose P1443, it’s essential to comprehend the EVAP system’s operation in Saab vehicles:

The fuel tank stores gasoline, which naturally produces vapors
These vapors are routed to the charcoal canister for temporary storage
The vent valve controls atmospheric ventilation to the canister
The purge valve regulates vapor flow to the engine intake
The ECM monitors system pressure and controls both valves
During refueling, the system allows vapors to be captured rather than released

Common Symptoms and Causes of P1443 in Saab Cars

Recognizing the symptoms associated with P1443 can help you identify the issue early and prevent potential complications. While some symptoms may be subtle, others can significantly impact your driving experience and vehicle performance.

Primary Symptoms of P1443 Code

Illuminated check engine light on your dashboard
Possible failed emissions test due to EVAP system malfunction
Fuel odor around the vehicle, particularly near the fuel tank
Difficulty refueling (clicking off fuel nozzle prematurely)
Decreased fuel efficiency in some cases
Rough engine idle if the purge system is affected

Root Causes of P1443 Diagnostic Trouble Code

Faulty EVAP vent control solenoid or valve
Damaged wiring or connectors in the vent control circuit
Blown fuse affecting the EVAP system components
Poor electrical connections at the vent valve or ECM
Failed charcoal canister (contaminated or damaged)
Blocked or restricted EVAP vent lines or hoses
Software or programming issue with the Engine Control Module
Physical damage to vent valve components from road debris

Comprehensive Diagnostic Procedure for P1443

Diagnosing P1443 requires a systematic approach to identify the exact cause efficiently. Always begin with visual inspections before proceeding to electrical tests, as many issues can be identified without specialized equipment.

Initial Visual Inspection Steps

Start your diagnosis with these crucial visual checks:

Inspect all EVAP system hoses for cracks, disconnections, or deterioration
Check the vent valve and associated wiring for obvious damage or corrosion
Examine the charcoal canister for physical damage or contamination
Verify all electrical connectors are securely seated and free of corrosion
Look for any obstructions around the vent valve inlet/outlet
Check relevant fuses in the engine compartment and interior fuse boxes

Electrical Circuit Testing Methods

After completing visual inspections, proceed with these electrical tests using a digital multimeter:

Test power and ground circuits at the vent valve connector
Check vent valve solenoid resistance against manufacturer specifications
Verify ECM command signals using a bidirectional scanner or oscilloscope
Perform continuity tests on wiring between ECM and vent valve
Check for short circuits to power or ground in control wires
Test voltage drop across connections to identify high resistance points

Advanced Diagnostic Techniques

For persistent P1443 codes, these advanced procedures may be necessary:

Use a smoke machine to detect leaks in the EVAP system
Perform active commands to the vent valve using a professional scan tool
Monitor live data parameters related to EVAP system operation
Check for technical service bulletins specific to your Saab model
Update ECM software if available recalls or reprogramming exists

Repair Procedures and Prevention Strategies

Once you’ve identified the root cause of P1443, proper repair techniques are essential for lasting resolution. The specific repair will depend on your diagnostic findings, but these procedures cover the most common solutions.

Common Repair Solutions for P1443

Replace faulty EVAP vent valve assembly
Repair or replace damaged wiring and connectors
Clear blocked vent lines and restore proper airflow
Replace contaminated or damaged charcoal canister
Address any ECM programming issues or updates
Replace blown fuses and investigate the cause of overload

Preventive Maintenance Tips

Preventing recurrence of P1443 involves regular maintenance and awareness:

Avoid overfilling your fuel tank during refueling
Keep the area around the fuel tank and EVAP components clean
Address other EVAP-related codes promptly to prevent system strain
Have your EVAP system inspected during routine maintenance
Protect underside components from road debris and corrosion
Use quality fuel to minimize contamination in the system

Successfully addressing a P1443 code in your Saab requires understanding the EVAP system’s function, methodical diagnosis, and proper repairs. While some DIY enthusiasts can tackle simpler aspects of this repair, complex electrical diagnostics and ECM-related issues often benefit from professional expertise. Always clear the code after repairs and verify the fix with a test drive and system monitor check to ensure complete resolution.

P2196 O2 Sensor A/F Signal Biased/Stuck Rich (Bank 1 Sensor 1)

Symptoms

For this DTC, the malfunction indicator light (MIL) illuminates. There may be other symptoms.

Causes

Potential causes of a P2196 code include:

Malfunction of the oxygen sensor (O2) or A/F ratio sensor or sensor heater
Open or shorted O2 sensor circuit (wiring, harness)
Fuel pressure or fuel injector issue
Faulty PCM
Intake air leaks or engine vacuum leaks
Faulty fuel injector(s)
Fuel pressure too high or too low
PCV system leak/failure
Faulty A/F sensor relay
MAF sensor malfunction
ECT sensor malfunction
Air intake restriction
Fuel pressure too high
Fuel pressure sensor malfunction
Fuel pressure regulator malfunction

Note: On some modified vehicles, this code may be caused by the modifications (e.g., aftermarket exhaust, headers, etc.).

Diagnostic Steps and Possible Solutions

If you do not have access to a scan tool, you can use a multimeter and backprobe the terminals of the O2 sensor wiring connector. Check for shorts to ground, shorts to power, open circuits, etc. Compare the specifications with the manufacturer’s specifications.

Visually inspect the wiring and connectors leading to the sensor, look for loose connectors, chafed/rubbed wires, melted wires, etc. Repair as necessary.

Visually inspect the vacuum lines. You can also test for vacuum leaks using propane or carburetor cleaner along the hoses while the engine is running; if the RPM changes, you have likely found the leak. Be very careful if you do this, and have a fire extinguisher handy in case of problems. If a vacuum leak proves to be the problem, it would be wise to replace all vacuum lines if they are aging, becoming brittle, etc.

Use a digital volt ohmmeter (DVOM) to check the proper operation of other mentioned sensors such as MAF, IAT.

Perform a fuel pressure test, check readings against manufacturer specifications.

If you are on a tight budget and only have an engine with more than one bank and the problem is only on one bank, you can swap the sensor from one bank to the other, clear the code, and see if the code follows to the other bank. This would tell you that it is the sensor/heater itself that has failed.

Check for any outstanding Technical Service Bulletins (TSBs) for your vehicle; in some cases, the PCM may be recalibrated to fix this issue (not a common solution however). TSBs might also call for sensor replacement.

When replacing oxygen/AF sensors, be sure to use high-quality sensors. In many cases, non-OEM sensors are of lower quality and will not function correctly. We strongly recommend sticking with OEM brand replacements.

P2197 O2 Sensor A/F Biased/Stuck Signal (Bank 2 Sensor 1)

Symptoms

For this DTC, the malfunction indicator light (MIL) illuminates. There may be other symptoms.

Causes

Potential causes for a P2197 code include:

Malfunction of the oxygen sensor (O2) or A/F ratio sensor or sensor heater
Open or shorted O2 sensor circuit (wiring, harness)
Fuel pressure or fuel injector issue
Faulty PCM
Intake air leaks or engine vacuum leaks
Faulty fuel injector(s)
Fuel pressure too high or too low
PCV system leak/failure
Faulty A/F sensor relay
MAF sensor malfunction
ECT sensor malfunction
Fuel pressure too low
Fuel leak
Air intake in the air intake system

Diagnostic Steps and Possible Solutions

Use a scan tool to obtain sensor readings and monitor short-term and long-term fuel trim values and O2 sensor or air/fuel ratio readings. Also, look at freeze frame data to see the conditions when the code was set. This should help determine if the AF O2 sensor is functioning correctly. Compare with manufacturer values.

If you don’t have access to a scan tool, you can use a multimeter and probe the terminals of the O2 sensor wiring connector again. Check for shorts to ground, shorts to power, open circuits, etc. Compare the specifications with the manufacturer’s specifications.

Visually inspect the wiring and connectors leading to the sensor, look for loose connectors, rubbed/chafed wires, melted wires, etc. Repair as necessary.

Visually inspect the vacuum lines. You can also test for vacuum leaks using propane or carburetor cleaner along the hoses while the engine is running; if the RPM changes, you’ve likely found the leak. Be very careful if you do this, and have a fire extinguisher on hand in case of issues. For example, on many Ford vehicles, the hose from the PCV to the throttle body can melt, causing codes P2195, P2197, P0171, and/or P0174. If a vacuum leak turns out to be the problem, it would be wise to replace all vacuum lines if they are aging, becoming brittle, etc.

Use a digital volt ohmmeter (DVOM) to check the proper operation of other mentioned sensors such as MAF, IAT.

Perform a fuel pressure test, check readings against manufacturer specifications.

If you’re on a tight budget and have an engine with more than one bank and the issue is only on one bank, you can swap the sensor from one bank to the other, clear the code, and see if the code follows to the other bank. This would tell you that it’s the sensor/heater itself that has failed.

Check for any outstanding technical service bulletins (TSB) for your vehicle; in some cases, the PCM may be recalibrated to resolve this issue (not a common solution, however). TSBs might also call for sensor replacement.

When replacing oxygen/AF sensors, make sure to use high-quality sensors. In many cases, non-OEM sensors are of lower quality and will not function properly. We strongly recommend sticking with OEM brand replacements.

P2198 O2 A/F Sensor Signal Biased/Stuck Rich (Bank 2 Sensor 1)

Symptoms

For this DTC, the malfunction indicator light (MIL) illuminates. There may be other symptoms such as increased fuel consumption.

Causes

Potential causes of a P2198 code include:

Malfunction of the oxygen sensor (O2) or A/F ratio sensor or sensor heater
Open or shorted O2 sensor circuit (wiring, harness)
Fuel pressure or fuel injector issue
Faulty PCM
Intake air leaks or engine vacuum leaks
Faulty fuel injector(s)
Fuel pressure too high or too low
PCV system leak/failure
Faulty A/F sensor relay
MAF sensor malfunction
ECT sensor malfunction
Air intake restriction
Fuel pressure too high
Fuel pressure sensor malfunction
Fuel pressure regulator malfunction
Note: On some vehicles that have been modified, this code may be caused by the modifications (e.g., aftermarket exhaust, headers, etc.).

Diagnostic Steps and Possible Solutions

Visually inspect the wiring and connectors leading to the sensor, look for loose connectors, chafed/rubbed wires, melted wires, etc. Repair as necessary.

Visually inspect the vacuum lines. You can also test for vacuum leaks using propane or carburetor cleaner along the hoses while the engine is running; if the RPM changes, you’ve likely found the leak. Be very careful if you do this, and have a fire extinguisher handy in case of problems. If a vacuum leak proves to be the problem, it would be wise to replace all vacuum lines if they are aging, becoming brittle, etc.

Use a digital volt ohmmeter (DVOM) to check the proper operation of other mentioned sensors such as MAF, IAT.

Perform a fuel pressure test, check readings against manufacturer specifications.

P2199 Intake Air Temperature Sensor Correlation 1/2

How serious is this DTC?

The IAT sensor input is essential for fuel delivery and ignition timing. A stored P2199 code should be treated as serious.

What are some symptoms of the code?

Symptoms of a P2199 trouble code may include:

Decreased engine performance
Reduced fuel efficiency
Hesitation during acceleration

What are some common causes of the code?

Causes of this code may include:

Disconnected IAT sensor
Faulty IAT sensor
Restricted air filter
Open or shorted circuits or connectors
PCM programming error or faulty PCM

What are the troubleshooting steps for P2199?

Start with an inspection of the air filter element. It should be inserted into the housing as intended—without dirt or debris.

If the air filter element is relatively clean and installed correctly, perform a visual inspection of the IAT sensor system wiring and connectors.

A diagnostic scanner, infrared thermometer (with a laser pointer), digital volt/ohmmeter (DVOM), and a reliable vehicle information source will be needed to diagnose a P2199.

At the end of a visual inspection, connect the scanner to the vehicle’s diagnostic port and retrieve all stored codes and freeze frame data. Note this information for later. Clear the codes and test the vehicle to see if P2199 resets.

Obtain diagnostic flowcharts, wiring diagrams, connector pinout diagrams, component testing procedures/specifications, and connector face views from your vehicle information source. This type of information, in addition to applicable technical service bulletins, can be crucial in the diagnostic process.

Disconnect the PCM (and any associated controllers) before testing individual system circuits with the DVOM. This will help prevent damage to the controller.

Test each IAT sensor:

Use the DVOM to test the IAT sensors
Set the DVOM to the ohms setting
Disconnect the sensor being tested
Follow the manufacturer’s component testing specifications
Sensors that do not meet testing specifications should be considered faulty

Test the reference circuit:

Use the DVOM to test the reference voltage (typically 5 V)
With the key on and engine off (KOEO), disconnect each IAT sensor connector
Using the DVOM’s positive test lead, probe the reference circuit pin of the IAT sensor connector
Simultaneously, probe the ground pin with the DVOM’s negative test lead
The reference voltage should be detected
If not, test the same circuit at the PCM connector. If no reference voltage signal is detected there, suspect a PCM issue or programming error.

Test each IAT sensor signal circuit:

Test each IAT sensor signal circuit using the DVOM
Plug in the IAT sensor
Use the DVOM’s positive test lead to probe the signal circuit of each sensor
The negative test lead should be connected to a chassis or engine ground
The infrared thermometer will be used to verify the actual IAT
Compare individual IAT sensor signal voltage levels at the sensor connectors with the actual IAT as reflected on the infrared thermometer
Use the temperature-to-voltage chart (found in the vehicle information source) to determine if each sensor is functioning properly
This is achieved by comparing individual IAT sensor data (collected in step 6 of the previous section) with the desired IAT voltage (reflected on the temperature-to-voltage chart).

If any IAT sensor does not reflect the appropriate voltage level (according to the temperature-to-voltage chart), suspect it is faulty.

If both the IAT and ambient air temperature sensor signal circuits reflect the appropriate voltage:

Use the DVOM to test the signal circuit (for the sensor in question) at the PCM connector
Consider there is an open circuit between the IAT and PCM if there is a proper sensor signal at the sensor connector but not at the PCM connector
Applicable Technical Service Bulletins (TSBs) will likely assist in your diagnosis

P219A Bank 1 Air/Fuel Ratio Imbalance

How severe is this DTC?

An incorrect air/fuel ratio can result from insufficient fuel or excess air (vacuum). A P219A code should be classified as severe and corrected as quickly as possible.

What are some symptoms of the code?

Symptoms of a P219A fault code may include:

Reduced fuel efficiency
General lack of engine performance
Stored misfire codes or lean/rich exhaust codes
Service engine soon light illumination

What are some common causes of the code?

Causes of this code may include:

Engine vacuum leak (large)
Faulty oxygen sensor(s)
Burned, chafed, broken, or disconnected wiring and/or connectors
Engine exhaust leaks
Faulty mass airflow or manifold air pressure sensor
Bad fuel pump or clogged fuel filter

What are the troubleshooting steps for P219A?

All misfire codes, throttle position sensor codes, manifold air pressure codes, and mass airflow sensor codes should be addressed before attempting to diagnose a P219A code. The engine must also be running properly and efficiently. If it’s determined that there is a rich or lean condition (with the engine), this must be repaired as it could be the cause of the P219A being stored.

You will need a diagnostic scanner, a digital volt/ohmmeter (DVOM), and a reliable source of vehicle information to accurately diagnose a P219A code.

You can save time by looking for Technical Service Bulletins (TSBs) that match the recorded code, vehicle (year, make, model, and engine), and the symptoms presented. This information can be found in your vehicle information source. If you find the right TSB, it might provide a quick solution to your diagnosis.

After connecting the scanner to the vehicle’s diagnostic port and retrieving all stored codes and relevant freeze frame data, note the information (in case the code turns out to be intermittent). After that, clear the codes and test the vehicle until one of two things happens; the code is restored or the PCM enters readiness mode.

The code may actually be more difficult to diagnose if the PCM enters readiness mode at this point, as the code is intermittent. The condition that caused the P219A to be stored may need to worsen before an accurate diagnosis can be made. If the code is restored, proceed with the diagnosis.

You can obtain connector face views, connector pinout charts, component location diagrams, wiring diagrams, and diagnostic flowcharts (related to the code and the vehicle in question) using your vehicle information source.

Perform a visual inspection of the associated wiring and connectors. Repair or replace wiring that has been cut, burned, or damaged.

If the engine is running smoothly and the P219A/P219B code continues to reset, start the engine and let it reach its normal operating temperature. Let the engine idle (with the transmission in neutral or park). With the scanner connected to the vehicle’s diagnostic port, observe the oxygen sensor input data on the data stream. Limit the scope of the data stream to include only relevant data, and you’ll get a faster response.

If the oxygen sensors are functioning normally, the voltage on the pre-cat oxygen sensors will continuously cycle between 1 and 900 millivolts once the PCM enters closed-loop operation. The post-cat sensors will also cycle between 1 and 900 millivolts, but they will stabilize at a certain point and remain relatively stable compared to the pre-cat sensors. Oxygen sensors that are not functioning properly should be considered faulty if the engine is in good running condition.

In most cases, you will fix this code by correcting a rich or lean running engine.