P2A39: The lambda sensor positive current control (bank 1
The lambda sensor positive current control (bank 1, sensor 3) gives a lower signal than normal. It is usually the sensor itself, its wiring or a real fault in what it measures.
| Code | P2A39 |
|---|---|
| System | Engine and transmission |
| Group | P2Axx, Engine and emissions |
| Type | Generic: it means the same on every make |
How to read and clear P2A39 with Final OBD
Plug an OBD2 scanner in under the steering wheel, switch the ignition on and open Final OBD. Under Faults you’ll see P2A39 with its description and whether it’s confirmed, pending or permanent.
If the engine stores it over standard OBD, with FREE you read this code with its explanation for nothing and clear it. With PRO you also read the faults of every control unit and clear them in all of them.
Clearing the code only turns the light off: if the cause is still there, it comes back. Clear it once it’s fixed, and not right before an inspection. It’s all in how to read and clear fault codes and in inspections and OBD.
Similar codes
- P2A2F The alternative fuel tank lock valve E control circuit has got stuck
- P2A30 The alternative fuel tank lock valve E control gives a lower signal than normal
- P2A31 The alternative fuel tank lock valve E control gives a higher signal than normal
- P2A38 The lambda sensor positive current control (bank 1
- P2A3A The lambda sensor positive current control (bank 1
- P2A3B The lambda sensor negative current control (bank 1
- P2A3C The lambda sensor negative current control (bank 1
- P2A3D The lambda sensor negative current control (bank 1
- P2A00 O2 sensor circuit range/performance (bank 1, sensor 1)
What does code P2A39 mean?
The lambda sensor positive current control (bank 1, sensor 3) gives a lower signal than normal. It is usually the sensor itself, its wiring or a real fault in what it measures.
How do you clear P2A39?
With an OBD2 scanner and an app like Final OBD, which clears it for free if it’s stored by the engine control unit. But clearing it only turns the light off: if the cause isn’t fixed, P2A39 comes back.
Read it on your car
Final OBD reads and clears engine faults through standard OBD for free, each one explained in plain English. With PRO it also reads the faults of every control unit, each make’s own codes included, and clears them in all of them.
