The 2001 Subaru Forester Obd2 Error Codes List is a valuable resource for diagnosing and addressing potential issues with your vehicle; MERCEDES-DIAGNOSTIC-TOOL.EDU.VN provides comprehensive information to help you understand these codes and take appropriate action. By understanding these codes, you can maintain your Subaru Forester’s optimal performance and longevity.
Contents
- 1. Understanding OBD2 Error Codes for Your 2001 Subaru Forester
- 1.1. What is the OBD2 System?
- 1.2. How to Retrieve OBD2 Error Codes
- 1.3. Common Categories of OBD2 Codes
- 2. Comprehensive List of 2001 Subaru Forester OBD2 Error Codes
- 2.1. P0000 – P0099: Fuel and Air Metering
- 2.2. P0100 – P0199: Fuel and Air Metering (Continued)
- 2.3. P0200 – P0299: Injector Circuit Malfunctions
- 2.4. P0300 – P0399: Misfire Detection
- 2.5. P0400 – P0499: Auxiliary Emission Controls
- 2.6. P0500 – P0599: Vehicle Speed Controls and Idle Control System
- 2.7. P0600 – P0699: Computer Output Circuit
- 2.8. P0700 – P0799: Transmission
- 2.9. P0800 – P0999: Transmission (Continued) and Hybrid Powertrain
- 2.10. P0A00 – P0C99: Hybrid Powertrain (Continued)
- 2.11. P2000 – P2AFF: Fuel and Air Metering and Auxiliary Emission Controls (Advanced)
1. Understanding OBD2 Error Codes for Your 2001 Subaru Forester
OBD2 (On-Board Diagnostics II) error codes are standardized codes used to diagnose issues within your vehicle’s engine and related systems. Accessing and understanding these codes empowers you to address potential problems promptly.
1.1. What is the OBD2 System?
The OBD2 system is a standardized system that monitors the performance of your vehicle’s engine, emissions control system, and other critical components. According to the Environmental Protection Agency (EPA), OBD2 systems have been mandatory on all cars and light trucks sold in the United States since 1996, ensuring consistent diagnostic capabilities.
1.2. How to Retrieve OBD2 Error Codes
To retrieve OBD2 error codes from your 2001 Subaru Forester, you’ll need an OBD2 scanner. Here’s how to use it:
- Locate the OBD2 Port: This is typically found under the dashboard on the driver’s side.
- Plug in the Scanner: Connect the OBD2 scanner to the port.
- Turn on the Ignition: Turn the key to the “ON” position without starting the engine.
- Read the Codes: Follow the scanner’s instructions to read the stored codes.
- Record the Codes: Write down any codes that appear for further investigation.
1.3. Common Categories of OBD2 Codes
OBD2 codes are categorized to help identify the area of the vehicle experiencing issues. The main categories include:
- P (Powertrain) Codes: These relate to the engine, transmission, and associated components.
- B (Body) Codes: These relate to body components like airbags, power windows, and central locking.
- C (Chassis) Codes: These relate to the chassis system, including ABS, brakes, and suspension.
- U (Network) Codes: These relate to the vehicle’s communication network.
2. Comprehensive List of 2001 Subaru Forester OBD2 Error Codes
Below is a detailed list of OBD2 error codes that your 2001 Subaru Forester might display, along with possible causes and troubleshooting tips. This information is crucial for accurate diagnostics and effective repairs.
2.1. P0000 – P0099: Fuel and Air Metering
These codes often involve issues with the fuel and air mixture, which can significantly affect engine performance and fuel efficiency.
| Code | Description | Possible Causes | Troubleshooting Tips |
|---|---|---|---|
| P0010 | “A” Camshaft Position Actuator Circuit (Bank 1) | Powertrain Control Module (PCM) failure, Variable valve timing actuator failure, Wiring issue. | Check wiring and connections, test the VVT actuator, inspect PCM. |
| P0011 | “A” Camshaft Position – Timing Over-Advanced or System Performance (Bank 1) | Camshaft variable timing solenoid failure, Low engine oil level, Incorrect engine timing, Non-compliant engine oil, Variable valve timing actuator failure, Worn timing chain. | Check oil level and quality, verify engine timing, inspect VVT solenoid and actuator, check timing chain wear. |
| P0012 | “A” Camshaft Position – Timing Over-Retarded (Bank 1) | Camshaft variable timing solenoid failure, Low engine oil level, Incorrect engine timing, Non-compliant engine oil, Variable valve timing actuator failure, Worn timing chain. | Check oil level and quality, verify engine timing, inspect VVT solenoid and actuator, check timing chain wear. |
| P0013 | “B” Camshaft Position Actuator Circuit (Bank 1) | Powertrain Control Module (PCM) failure, Variable valve timing actuator failure, Wiring issue. | Check wiring and connections, test the VVT actuator, inspect PCM. |
| P0014 | “B” Camshaft Position – Timing Over-Advanced or System Performance (Bank 1) | Camshaft variable timing solenoid failure, Low engine oil level, Incorrect engine timing, Non-compliant engine oil, Variable valve timing actuator failure, Worn timing chain. | Check oil level and quality, verify engine timing, inspect VVT solenoid and actuator, check timing chain wear. |
| P0101 | Mass Air Flow (MAF) Sensor Circuit Range/Performance | Large vacuum leaks, Split Intake Air Boot or PCV Hose, Defective intake manifold gaskets, Mass Airflow Sensor (MAF), Circuit and wiring problems, Defective Barometric Pressure Sensor. | Check for vacuum leaks, inspect MAF sensor and wiring, check intake manifold gaskets, update PCM software. |
| P0102 | Mass Air Flow (MAF) Sensor Circuit Low Input | Unplugged or damaged MAF Sensor wiring, Loose or corroded electrical terminals, Faulty MAF Sensor. | Check MAF sensor connections and wiring, clean or replace MAF sensor. |
| P0113 | Intake Air Temperature Sensor Circuit High Input | Defective Intake Air Temperature Sensor, Dirty air filter, Defective Mass Air Flow Sensor, Faulty or corroded wiring or connections. | Check IAT sensor and wiring, replace dirty air filter, inspect MAF sensor. |
2.2. P0100 – P0199: Fuel and Air Metering (Continued)
These codes continue to address issues related to fuel and air intake, temperature sensors, and overall system efficiency.
| Code | Description | Possible Causes | Troubleshooting Tips |
|---|---|---|---|
| P0128 | Coolant Thermostat (Coolant Temperature Below Thermostat Regulating Temperature) | Defective Engine Thermostat, Defective Engine Coolant Temperature Sensor, Defective Intake Air Temperature Sensor, Defective Cooling System, Low Engine Coolant. | Check and replace thermostat, inspect coolant temperature sensor, check cooling system for leaks. |
| P0135 | O2 Sensor Heater Circuit Malfunction (Bank 1, Sensor 1) | Defective Oxygen Sensor/Air Fuel Ratio Sensor, Exhaust System Leak, Intake Air System leak, Low Fuel Pressure. | Check O2 sensor and heater circuit, inspect exhaust and intake systems for leaks, check fuel pressure. |
| P0171 | System Too Lean (Bank 1) | Control module software needs to be updated, Vacuum leaks, Mass air flow sensor, Plugged fuel filter or weak fuel pump, Plugged or dirty fuel injectors. | Check for vacuum leaks, inspect MAF sensor, replace fuel filter, clean or replace fuel injectors, update control module software. |
| P0174 | System Too Lean (Bank 2) | PCM software needs to be updated, Vacuum leaks, Faulty Mass Airflow (MAF) Sensor, Plugged Fuel Filter or weak Fuel Pump, Plugged or dirty Fuel Injectors. | Check for vacuum leaks, inspect MAF sensor, replace fuel filter, clean or replace fuel injectors, update PCM software. |
2.3. P0200 – P0299: Injector Circuit Malfunctions
These codes relate to issues with the fuel injectors, which are critical for delivering the correct amount of fuel to the engine cylinders.
| Code | Description | Possible Causes | Troubleshooting Tips |
|---|---|---|---|
| P0200 | Injector Circuit Malfunction | Defective Fuel Injector, Faulty or corroded wiring and connections, Plugged Fuel Injector, Dirt in the Fuel Injector. | Check fuel injector wiring and connections, clean or replace fuel injectors. |
| P0201 | Cylinder 1 Injector Circuit Malfunction | Defective Fuel Injector, Faulty or corroded wiring and connections, Plugged Fuel Injector, Dirt in the Fuel Injector. | Check fuel injector wiring and connections, clean or replace fuel injectors. |
| P0202 | Cylinder 2 Injector Circuit Malfunction | Malfunction of the Fuel Injector, Malfunction of the PCM Fuel Injector driver circuit, Defective wiring/connections. | Check fuel injector wiring and connections, inspect PCM, replace fuel injector. |
| P0203 | Cylinder 3 Injector Circuit Malfunction | Fuel injector failure, Powertrain Control Module (PCM) failure, Wiring issue. | Check fuel injector wiring, inspect PCM, replace fuel injector. |
| P0205 | Cylinder 5 Injector Circuit Malfunction | Fuel injector failure, Powertrain Control Module (PCM) failure, Wiring issue. | Check fuel injector wiring, inspect PCM, replace fuel injector. |
2.4. P0300 – P0399: Misfire Detection
Misfire codes indicate that one or more cylinders are not firing correctly, which can lead to rough running and decreased power.
| Code | Description | Possible Causes | Troubleshooting Tips |
|---|---|---|---|
| P0300 | Random/Multiple Cylinder Misfire Detected | Worn out spark plugs, ignition wires, coil(s), Vacuum leak(s), Low or weak fuel pressure, Improperly functioning EGR system, Defective Mass Air Flow Sensor. | Replace spark plugs and ignition wires, check for vacuum leaks, inspect fuel pressure, check EGR system and MAF sensor. |
| P0301 | Cylinder 1 Misfire Detected | Worn out spark plugs, ignition wires, coil(s), Vacuum leak(s), Low or weak fuel pressure, Improperly functioning EGR system, Defective Mass Air Flow Sensor. | Replace spark plugs and ignition wires, check for vacuum leaks, inspect fuel pressure, check EGR system and MAF sensor. |
| P0302 | Cylinder 2 Misfire Detected | Worn out spark plugs, ignition wires, coil(s), Vacuum leak(s), Low or weak fuel pressure, Improperly functioning EGR system, Defective Mass Air Flow Sensor. | Replace spark plugs and ignition wires, check for vacuum leaks, inspect fuel pressure, check EGR system and MAF sensor. |
| P0303 | Cylinder 3 Misfire Detected | Worn out spark plugs, ignition wires, coil(s), Vacuum leak(s), Low or weak fuel pressure, Improperly functioning EGR system, Defective Mass Air Flow Sensor. | Replace spark plugs and ignition wires, check for vacuum leaks, inspect fuel pressure, check EGR system and MAF sensor. |
| P0304 | Cylinder 4 Misfire Detected | Worn out spark plugs, ignition wires, coil(s), Vacuum leak(s), Low or weak fuel pressure, Improperly functioning EGR system, Defective Mass Air Flow Sensor. | Replace spark plugs and ignition wires, check for vacuum leaks, inspect fuel pressure, check EGR system and MAF sensor. |
2.5. P0400 – P0499: Auxiliary Emission Controls
These codes pertain to issues with the emission control systems, which are vital for reducing harmful pollutants.
| Code | Description | Possible Causes | Troubleshooting Tips |
|---|---|---|---|
| P0401 | Exhaust Gas Recirculation Flow Insufficient Detected | Restriction in the EGR passages, The EGR Valve is defective, Lack of proper vacuum or electrical signal to the EGR valve, Malfunctioning EGR Vacuum supply solenoid, Lack of proper EGR system feedback. | Check EGR passages for blockage, test EGR valve, check vacuum and electrical signals to EGR valve, inspect EGR vacuum supply solenoid, check feedback from MAP, DPFE, EVP, and EGR Temperature Sensors. |
| P0420 | Catalyst System Efficiency Below Threshold (Bank 1) | Inefficient Catalytic Converter(s), Defective Front or Rear Oxygen Sensor(s), Misfiring engines. | Check catalytic converter efficiency, inspect oxygen sensors, address any engine misfires. |
| P0430 | Catalyst System Efficiency Below Threshold (Bank 2) | Defective Catalytic Converter, Internal engine damage resulting in high oil consumption and/or a leaking Head Gasket has damaged the Catalytic Converter. | Check catalytic converter, inspect engine for internal damage and head gasket leaks. |
| P0440 | Evaporative Emission Control System Malfunction | Missing fuel cap, Defective or damaged fuel cap, Distorted or damaged Fuel Tank Filler Neck, Torn or punctured Evaporative system hose(s), Defective Fuel Tank Sending Unit gasket or seal. | Check fuel cap, inspect fuel tank filler neck, check evaporative system hoses, check fuel tank sending unit gasket. |
| P0441 | Evaporative Emission Control System Incorrect Purge Flow | Missing fuel cap, Stuck open or closed purge valve, Defective or damaged fuel cap, Distorted, damaged or cracked Fuel Tank Filler Neck, Torn or punctured Evaporative system hose(s). | Check fuel cap, test purge valve, inspect fuel tank filler neck, check evaporative system hoses. |
| P0442 | Evaporative Emission Control System Leak Detected (small leak) | Defective or damaged fuel cap, Distorted or damaged Fuel Tank Filler Neck, Small tear or puncture in the Evaporative system hose(s) and/or Carbon Canister, Defective Fuel Tank Sending Unit gasket or seal. | Check fuel cap, inspect fuel tank filler neck, check evaporative system hoses and carbon canister, check fuel tank sending unit gasket. |
| P0455 | Evaporative Emission Control System Leak Detected (large leak) | Missing fuel cap, Defective or damaged fuel cap, Distorted or damaged Fuel Tank Filler Neck, Torn or punctured Evaporative system hose(s), Defective Fuel Tank Sending Unit gasket or seal. | Check fuel cap, inspect fuel tank filler neck, check evaporative system hoses, check fuel tank sending unit gasket. |
2.6. P0500 – P0599: Vehicle Speed Controls and Idle Control System
These codes relate to issues with maintaining proper vehicle speed and idle, which can affect driveability and fuel consumption.
| Code | Description | Possible Causes | Troubleshooting Tips |
|---|---|---|---|
| P0500 | Vehicle Speed Sensor Malfunction | Defective Vehicle Speed Sensor, Defective Speedometer, Vehicle Speed Sensor wiring or connector problems. | Check vehicle speed sensor, speedometer, and associated wiring and connectors. |
| P0501 | Vehicle Speed Sensor Range/Performance | Defective Vehicle Speed Sensor, Defective Speedometer, Vehicle Speed Sensor wiring or connector problems. | Check vehicle speed sensor, speedometer, and associated wiring and connectors. |
| P0505 | Idle Air Control System Malfunction | Defective Idle Air Control Motor, Intake Manifold Vacuum leaks, Carbon buildup in the Throttle Body air passages. | Check idle air control motor, inspect for intake manifold vacuum leaks, clean throttle body. |
| P0506 | Idle Air Control System RPM Lower Than Expected | Defective/sticking Idle Air Control Motor, Intake Manifold Vacuum leaks, Carbon buildup in the Throttle Body. | Check idle air control motor, inspect for intake manifold vacuum leaks, clean throttle body. |
| P0507 | Idle Air Control System RPM Higher Than Expected | Defective/sticking Idle Air Control Motor, Intake Manifold Vacuum leaks, Carbon buildup in the Throttle Body. | Check idle air control motor, inspect for intake manifold vacuum leaks, clean throttle body. |
2.7. P0600 – P0699: Computer Output Circuit
These codes refer to problems with the vehicle’s computer systems, which can affect a wide range of functions.
| Code | Description | Possible Causes | Troubleshooting Tips |
|---|---|---|---|
| P0600 | Serial Communication Link Malfunction | Defective PCM (Power Train Control Module), Defective PCM data bus wiring/connections, Defective CAN bus. | Check PCM and associated wiring and connections, inspect CAN bus. |
| P0601 | Internal Control Module Memory Check Sum Error | Lack of proper voltage to the PCM, Defective PCM memory module, Defective PCM ground circuit(s). | Check PCM voltage and ground, inspect PCM memory module. |
| P0602 | Control Module Programming Error | Powertrain Control Module (PCM) failure, Wiring issue. | Check PCM and associated wiring. |
| P0603 | Internal Control Module Keep Alive Memory (KAM) Error | Lack of proper voltage to the Keep Alive Memory connection on the PCM, Defective PCM ground circuit(s). | Check PCM voltage and ground, inspect PCM. |
| P0605 | Internal Control Module Read Only Memory (ROM) Error | Lack of proper voltage and/or ground to the PCM, Defective PCM ground circuit(s). | Check PCM voltage and ground, inspect PCM. |
2.8. P0700 – P0799: Transmission
These codes indicate issues with the transmission system, which is critical for smooth gear changes and overall vehicle performance.
| Code | Description | Possible Causes | Troubleshooting Tips |
|---|---|---|---|
| P0700 | Transmission Control System Malfunction | Defective Shift Solenoids, Defective Engine Coolant Temperature Sensor, Defective Valve Body, Dirty transmission fluid. | Check shift solenoids, engine coolant temperature sensor, valve body, and transmission fluid condition. |
| P0705 | Transmission Range Sensor Circuit Malfunction (PRNDL Input) | Defective Transmission Range Sensor (PRNDL input), Defective wiring or connector, Defective Valve Body, Defective manual shift valve linkage. | Check transmission range sensor, wiring, connector, valve body, and manual shift valve linkage. |
| P0706 | Transmission Range Sensor Circuit Range/Performance | Defective Transmission Range Sensor (PRNDL input), Defective wiring or connector, Defective Valve Body, Defective manual shift valve linkage. | Check transmission range sensor, wiring, connector, valve body, and manual shift valve linkage. |
| P0720 | Output Speed Sensor Circuit Malfunction | Defective Output Speed Sensor, Defective Shift Solenoids, Defective Engine Coolant Temperature Sensor, Defective Valve Body, Dirty transmission fluid. | Check output speed sensor, shift solenoids, engine coolant temperature sensor, valve body, and transmission fluid condition. |
| P0730 | Incorrect Gear Ratio | Defective Shift Solenoids, Defective Engine Coolant Temperature Sensor, Defective Valve Body, Dirty transmission fluid. | Check shift solenoids, engine coolant temperature sensor, valve body, and transmission fluid condition. |
2.9. P0800 – P0999: Transmission (Continued) and Hybrid Powertrain
This range continues the transmission-related codes and includes codes for hybrid powertrain systems, reflecting advancements in vehicle technology.
| Code | Description | Possible Causes | Troubleshooting Tips |
|---|---|---|---|
| P0841 | Transmission Fluid Pressure Sensor/Switch “A” Circuit Range/Performance | Transmission Control Module (TCM) failure, Low transmission fluid level, Transmission fluid pressure sensor failure, Wiring issue. | Check TCM, transmission fluid level, transmission fluid pressure sensor, and wiring. |
| P0842 | Transmission Fluid Pressure Sensor/Switch “A” Circuit Low | Transmission Control Module (TCM) failure, Low transmission fluid level, Transmission fluid pressure sensor failure, Wiring issue. | Check TCM, transmission fluid level, transmission fluid pressure sensor, and wiring. |
| P0845 | Transmission Fluid Pressure Sensor/Switch “B” Circuit | Transmission Control Module (TCM) failure, Low transmission fluid level, Transmission fluid pressure sensor failure, Wiring issue. | Check TCM, transmission fluid level, transmission fluid pressure sensor, and wiring. |
| P0846 | Transmission Fluid Pressure Sensor/Switch “B” Circuit Range/Performance | Transmission Control Module (TCM) failure, Low transmission fluid level, Transmission fluid pressure sensor failure, Wiring issue. | Check TCM, transmission fluid level, transmission fluid pressure sensor, and wiring. |
| P0847 | Transmission Fluid Pressure Sensor/Switch “B” Circuit Low | Transmission Control Module (TCM) failure, Low transmission fluid level, Transmission fluid pressure sensor failure, Wiring issue. | Check TCM, transmission fluid level, transmission fluid pressure sensor, and wiring. |
| P0901 | Clutch Actuator Circuit Range/Performance | Clutch master cylinder failure, Clutch solenoid failure, Transmission Control Module (TCM) failure. | Check clutch master cylinder, clutch solenoid, and TCM. |
| P0935 | Hydraulic Pressure Sensor Range/Performance | Hydraulic power unit assembly failure, Transmission Control Module (TCM) failure, Wiring issue. | Check hydraulic power unit assembly, TCM, and wiring. |
| P0942 | Hydraulic Power Unit Activated Too Long | Hydraulic power unit assembly failure, Transmission Control Module (TCM) failure, Wiring issue. | Check hydraulic power unit assembly, TCM, and wiring. |
| P0944 | Loss of Hydraulic Pressure | Clogged transmission filter, Transmission fluid level is low, Transmission oil pump failure, Wiring issue. | Check transmission filter, fluid level, oil pump, and wiring. |
| P0961 | Pressure Control Solenoid “A” Control Circuit Range/Performance | Transmission shift solenoid failure. | Check transmission shift solenoid. |
2.10. P0A00 – P0C99: Hybrid Powertrain (Continued)
These codes focus on issues specific to hybrid vehicles, including the inverter, converter, and high-voltage systems.
| Code | Description | Possible Causes | Troubleshooting Tips |
|---|---|---|---|
| P0A08 | DC/DC Converter Circuit Malfunction | Inverter/converter assembly failure, Powertrain Control Module (PCM) failure, Wiring issue. | Check inverter/converter assembly, PCM, and wiring. |
| P0A0D | High Voltage System Interlock Circuit Malfunction | High voltage safety device failure, Inverter/converter assembly failure, Power management control module failure. | Check high voltage safety device, inverter/converter assembly, and power management control module. |
| P0A0F | Engine Failed to Start | Hybrid transaxle assembly failure, Internal engine failure, Power management control module failure. | Check hybrid transaxle assembly, engine, and power management control module. |
| P0A7F | Battery Module Deterioration | Poor connections at the HV battery, A problem with the HV battery, ECU issues. | Check HV battery connections, HV battery condition, and ECU. |
| P0A80 | Replace Hybrid Battery Pack | High voltage battery assembly failure. | Replace high voltage battery assembly. |
| P0B22 | Hybrid Battery Contactor Circuit “A” Stuck Closed | Battery contactor assembly failure, Battery Energy Control Module (BECM) failure. | Check battery contactor assembly and BECM. |
| P0B24 | Hybrid Battery Voltage Sense “A” Circuit Range/Performance | Battery Energy Control Module (BECM) failure, High voltage battery assembly failure, Wiring issue. | Check BECM, high voltage battery assembly, and wiring. |
| P0B26 | Hybrid Battery Voltage Sense “B” Circuit Range/Performance | Battery Energy Control Module (BECM) failure, High voltage battery assembly failure, Wiring issue. | Check BECM, high voltage battery assembly, and wiring. |
| P0B28 | Hybrid Battery Voltage Sense “C” Circuit Range/Performance | Battery Energy Control Module (BECM) failure, High voltage battery assembly failure, Wiring issue. | Check BECM, high voltage battery assembly, and wiring. |
| P0B30 | Hybrid Battery Voltage Sense “E” Circuit Range/Performance | Battery Energy Control Module (BECM) failure, High voltage battery assembly failure, Wiring issue. | Check BECM, high voltage battery assembly, and wiring. |
| P0C00 | Drive Motor “A” Inverter Performance | Drive motor generator power inverter control module failure. | Check drive motor generator power inverter control module. |
| P0C09 | Generator Inverter Performance | Drive motor generator assembly failure, Drive motor generator power inverter control module failure. | Check drive motor generator assembly and power inverter control module. |
| P0C11 | Drive Motor “A” Coolant Pump Control Circuit/Open | Coolant system leak, Drive motor generator power inverter control module failure, Engine cooling fan failure, Water pump failure. | Check coolant system, drive motor generator power inverter control module, engine cooling fan, and water pump. |
| P0C14 | Drive Motor “B” Coolant Pump Control Circuit/Open | Coolant system leak, Drive motor generator power inverter control module failure, Engine cooling fan failure, Water pump failure. | Check coolant system, drive motor generator power inverter control module, engine cooling fan, and water pump. |
| P0C15 | Drive Motor “B” Coolant Pump Control Circuit Low | Coolant system leak, Drive motor generator power inverter control module failure, Engine cooling fan failure, Water pump failure. | Check coolant system, drive motor generator power inverter control module, engine cooling fan, and water pump. |
2.11. P2000 – P2AFF: Fuel and Air Metering and Auxiliary Emission Controls (Advanced)
These codes address more specific fuel and air metering issues and advanced emission control problems, often found in newer vehicles or those with advanced systems.
| Code | Description | Possible Causes | Troubleshooting Tips |
|---|---|---|---|
| P2000 | NOx Adsorber Efficiency Below Threshold Bank 1 | Diesel Particulate Filter (DPF) failure, Intake air leak, Mass Airflow (MAF) sensor is dirty/loss of calibration. | Check DPF, intake for leaks, and MAF sensor. |
| P2002 | Diesel Particulate Filter Efficiency Below Threshold Bank 1 | Diesel Particulate Filter (DPF) failure, Intake air leak, Mass Airflow (MAF) sensor is dirty/loss of calibration. | Check DPF, intake for leaks, and MAF sensor. |
| P2004 | Intake Manifold Runner Control Stuck Open Bank 1 | A failed IMRC actuator, A problem with the intake manifold or linkage, Wiring issues. | Check IMRC actuator, intake manifold and linkage, and wiring. |
| P2006 | Intake Manifold Runner Control Stuck Closed Bank 1 | Intake manifold runner control actuator failure, Powertrain Control Module (PCM) failure, Restricted vacuum lines. | Check intake manifold runner control actuator, PCM, and vacuum lines. |
| P2101 | Throttle Actuator Control Motor Circuit Range/Performance | Accelerator Pedal Position (APP) assembly failure, Powertrain Control Module (PCM) failure, Throttle control motor failure. | Check APP assembly, PCM, and throttle control motor. |
| P2122 | Throttle/Pedal Position Sensor/Switch “D” Circuit Low Input | Accelerator Pedal Position (APP) assembly failure, Powertrain Control Module (PCM) failure, Throttle control motor failure. | Check APP assembly, PCM, and throttle control motor. |
| P2135 | Throttle/Pedal Position Sensor/Switch “A”/”B” Voltage Correlation | Accelerator Pedal Position (APP) assembly failure, Powertrain Control Module (PCM) failure, Throttle Position Sensor (TPS) failure. | Check APP assembly, PCM, and TPS. |
| P2138 | Throttle/Pedal Position Sensor/Switch “D”/”E” Voltage Correlation | Accelerator Pedal Position (APP) assembly failure, Powertrain Control Module (PCM) failure, Throttle Position Sensor (TPS) failure. | Check APP assembly, PCM, and TPS. |
| P2181 | Cooling System Performance | Engine coolant heater failure, Engine coolant level is too low, Thermostat failure. | Check engine coolant heater, coolant level, and thermostat. |
| P2210 | NOx Sensor Circuit Malfunction Bank 1 | NOx sensor failure, Powertrain Control Module (PCM) failure, Wiring issue. | Check NOx sensor, PCM, and wiring. |
| P2213 | NOx Sensor Circuit Malfunction Bank 2 | NOx sensor failure, Powertrain Control Module (PCM) failure, Wiring issue. | Check NOx sensor, PCM, and wiring. |
| P2237 | O2 Sensor Pumping Current Circuit Open Bank 1 Sensor 1 | Exhaust leak, Oxygen sensor failure, Powertrain Control Module (PCM) failure, Wiring issue. | Check for exhaust leaks, oxygen sensor, PCM, and wiring. |
| P2238 | O2 Sensor Pumping Current Circuit Low Bank 1 Sensor 1 | Exhaust leak, Oxygen sensor failure, Powertrain Control Module (PCM) failure, Wiring issue. | Check for exhaust leaks, oxygen sensor, PCM, and wiring. |
| P2251 | O2 Sensor Control Circuit High Bank 1 Sensor 1 | Exhaust leak, Oxygen sensor failure, Powertrain Control Module (PCM) failure, Wiring issue. | Check for exhaust leaks, oxygen sensor, PCM, and wiring. |
| P2302 | Ignition Coil “A” Secondary Circuit | Ignition coil failure, Powertrain Control Module (PCM) failure, Wiring issue. | Check ignition coil, PCM, and wiring. |
| P2303 | Ignition Coil “B” Secondary Circuit | Ignition coil failure, Powertrain Control Module (PCM) failure, Wiring issue. | Check ignition coil, PCM, and wiring. |
| P2305 | Ignition Coil “C” Secondary Circuit | Ignition coil failure, Powertrain Control Module (PCM) failure, Wiring issue. | Check ignition coil, PCM, and wiring. |
| P2308 | Ignition Coil “D” Secondary Circuit | Ignition coil failure, Powertrain Control Module (PCM) failure, Wiring issue. | Check ignition coil, PCM, and wiring. |
| P2310 | Ignition Coil “E” Secondary Circuit | Ignition coil failure, Powertrain Control Module (PCM) failure, Wiring issue. | Check ignition coil, PCM, and wiring. |
| P2401 | Evaporative Emission System Leak Detection Pump Control Circuit Open | Evap leak detection pump failure, Powertrain Control Module (PCM) failure, Wiring issue. | Check evap leak detection pump, PCM, and wiring. |
| P2402 | Evaporative Emission System Leak Detection Pump Control Circuit Shorted | Evap leak detection pump failure, Powertrain Control Module (PCM) failure, Wiring issue. | Check evap leak detection pump, PCM, and wiring. |
| P2422 | Evaporative Emission System Vent Valve Stuck Closed | EVAP vent valve failure, Powertrain Control Module (PCM) failure, Wiring issue. | Check EVAP vent valve, PCM, and wiring. |
| P2431 | Secondary Air Injection System Air Flow/Pressure Sensor Circuit Range/Performance Bank 1 | Air control solenoid failure, Powertrain Control Module (PCM) failure, Secondary Air System pressure sensor failure. | Check air control solenoid, PCM, and secondary air system pressure sensor. |
| P2432 | Secondary Air Injection System Air Flow/Pressure Sensor Circuit Range/Performance Bank 2 | Air control solenoid failure, Powertrain Control Module (PCM) failure, Secondary Air System pressure sensor failure. | Check air control solenoid, PCM, and secondary air system pressure sensor. |
| P2500 | Charging System Voltage Low | Alternator failure, Battery failure, Powertrain Control Module (PCM) failure, Wiring issue. | Check alternator, battery, PCM, and wiring. |
| P2501 | Charging System Voltage High | Alternator failure, Battery failure, Powertrain Control Module (PCM) failure, Wiring issue. | Check alternator, battery, PCM, and wiring. |
| P2503 | Charging System Voltage Too Low | Alternator failure, Battery failure, Wiring issue. | Check alternator, battery, and wiring. |
| P2509 | ECM/PCM Power Input Signal Intermittent | Powertrain Control Module (PCM) failure, Powertrain Control Module (PCM) power relay failure, Wiring issue. | Check PCM, PCM power relay, and wiring. |
| P250C | Engine Oil Level Sensor Circuit Range/Performance | Oil level sensor failure, Powertrain Control Module (PCM) failure, Wiring issue. |
