As you happen to be driving your Volkswagen on the same day your “Check Engine” light comes on, you can’t help but wonder what’s going on under the hood. It’s almost as if the universe wanted you to pay attention to your car’s internal workings. Well, it’s a good thing you did, because that light is trying to tell you something – and it’s not just a vague warning.
Your Volkswagen’s On-Board Diagnostics II (OBD-II) system has detected an issue and is waiting for you to uncover the specific problem hidden behind a cryptic code. But what does that code mean, exactly?
Understanding OBD-II Codes
Every Volkswagen vehicle manufactured since 1996 is equipped with an On-Board Diagnostics II (OBD-II) system, a standardized diagnostics protocol that monitors and reports on the vehicle’s engine management and transmission systems.
When a malfunction occurs, the OBD-II system records a Diagnostic Trouble Code (DTC) and illuminates the Malfunction Indicator Light (MIL) – also known as the check engine light – on your dashboard.
Each DTC consists of a numerical code and a P-code, which follows a standard format defined by the Society of Automotive Engineers (SAE).
Certified Volkswagen specialists are trained to interpret these OBD-II trouble codes, ensuring accurate diagnosis and correct repairs.
They use advanced diagnostic equipment to read the codes and identify the malfunction, preventing incorrect repairs that can lead to further issues.
Common Error Codes Explained
Now that you’re familiar with how Volkswagen’s OBD-II system works, it’s time to examine the common error codes that may appear.
As you’re troubleshooting issues with your vehicle, it’s essential to understand the codes that the Volkswagen diagnostic system generates. The code you’re looking for is a standardized format, defined by the Society of Automotive Engineers (SAE), to help automotive engineers identify trouble areas in your vehicle.
- P0171: System Too Lean: Indicates that the fuel mixture is too lean, which can cause engine performance issues.
- P0420: Catalyst System Efficiency Below Threshold: Suggests that the catalytic converter isn’t functioning correctly, leading to increased emissions.
- P0700: Transmission Control Module (TCM) Requested MIL Illumination: Indicates a problem with the transmission control module, which may cause issues with shifting or performance.
Diagnosing and Repairing Issues
When diagnosing issues with your Volkswagen, it’s crucial to understand the root cause of the problem to guarantee precise repair. As a car owner, you should be aware that continued use of your vehicle with an illuminated Malfunction Indicator Light (MIL) can lead to further damage and decreased performance. Certified Volkswagen specialists use advanced diagnostic equipment to verify accurate diagnosis and repair of issues.
| Diagnostic Tool | Function | Benefit |
|---|---|---|
| VW/Audi Factory Scan Tools | Retrieves DTCs and provides detailed information | Accurate diagnosis and repair |
| Commercially available scan tools | Retrieves DTCs and provides basic information | Cost-effective diagnosis |
| OBD-II system | Monitors engine management and transmission operation | Guarantees compliance with emission levels |
| Trained technician | Diagnoses and repairs common issues | Improves vehicle performance and safety
Most Common Volkswagen OBD-II Trouble Codes
| Code | Description |
|---|---|
| P0010 | Camshaft Position Actuator Circuit Bank 1 Malfunction |
| P0020 | Camshaft Position Actuator Circuit Bank 2 Malfunction |
| P0101 | Mass/Volume Air Flow Circuit Range/Performance |
| P0102 | Mass/Volume Air Flow Circuit Low Input |
| P0103 | Mass/Volume Air Flow Circuit High Input |
| P0105 | Manifold Absolute Pressure/Barometric Pressure Voltage Supply |
| P0106 | Manifold Absolute Pressure/Barometric Pressure Range/Performance |
| P0107 | Manifold Absolute Pressure/Barometric Pressure Low Input |
| P0108 | Manifold Absolute Pressure/Barometric Pressure High Input |
Fuel System Codes
| Code | Description |
|---|---|
| P0170 | Fuel Trim Bank 1 Malfunction |
| P0171 | Fuel Trim Bank 1 System Too Lean |
| P0172 | Fuel Trim Bank 1 System Too Rich |
| P0173 | Fuel Trim Bank 2 Malfunction |
| P0174 | Fuel Trim Bank 2 System Too Lean |
| P0175 | Fuel Trim Bank 2 System Too Rich |
| P0201 | Cylinder 1 Injector Circuit Fault |
| P0202 | Cylinder 2 Injector Circuit Fault |
| P0203 | Cylinder 3 Injector Circuit Fault |
| P0204 | Cylinder 4 Injector Circuit Fault |
Oxygen Sensor Codes
| Code | Description |
|---|---|
| P0130 | O2 Sensor Circuit Bank 1-Sensor 1 Malfunction |
| P0131 | O2 Sensor Circuit Bank 1-Sensor 1 Low Voltage |
| P0132 | O2 Sensor Circuit Bank 1-Sensor 1 High Voltage |
| P0133 | O2 Sensor Circuit Bank 1-Sensor 1 Slow Response |
| P0134 | O2 Sensor Circuit Bank 1-Sensor 1 No Activity |
| P0135 | O2 Sensor Heater Circuit Bank 1-Sensor 1 Malfunction |
Transmission Codes
| Code | Description |
|---|---|
| P0700 | Transmission Control System Malfunction |
| P0702 | Transmission Control System Electrical |
| P0705 | Transmission Range Sensor Circuit Malfunction |
| P0706 | Transmission Range Sensor Circuit Range/Performance |
| P0707 | Transmission Range Sensor Circuit Low Input |
| P0708 | Transmission Range Sensor Circuit High Input |
Engine Temperature Codes
| Code | Description |
|---|---|
| P0116 | Engine Coolant Temperature Circuit Range/Performance |
| P0117 | Engine Coolant Temperature Circuit Low Input |
| P0118 | Engine Coolant Temperature Circuit High Input |
| P0125 | Insufficient Coolant Temperature for Closed Loop Control |
| P0128 | Coolant Thermostat Temperature Below Control Range |
Turbocharger Codes
| Code | Description |
|---|---|
| P0234 | Turbocharger Overboost Condition |
| P0235 | Turbocharger Boost Sensor Circuit Control Limit Not Reached |
| P0236 | Turbocharger Boost Sensor Circuit Range/Performance |
| P0237 | Turbocharger Boost Sensor Circuit Low Input |
| P0238 | Turbocharger Boost Sensor Circuit High Input |
