PowertrainP2251
CautionSeverity: Caution - get it checked when you can
Upstream oxygen sensor negative current control circuit open
Key terms: Oxygen sensor: measures oxygen in the exhaust gas · Control module: a small computer that runs one part of the car · Powertrain: engine, transmission and emissions
1What it means in plain English
The engine or powertrain control system has stored a fault that does not have specific guidance in this database yet.
2Common causes
- Sensor or actuator fault
- Wiring or connector fault
- Vacuum or intake leak
- Fuel or ignition problem
- Control module fault
3Can I drive?
Have it diagnosed promptly. If the car runs and drives normally, drive gently to a workshop. If it runs badly, stalls, overheats, loses oil pressure, or a warning light is flashing or red, stop safely and get professional help. If the code concerns the brakes, brake vacuum or brake assist, do not drive until it is checked: a hard pedal or longer stopping distance means stop.
This page gives general information. It is not professional advice. For a definite diagnosis and a repair quote, ask a qualified mechanic to inspect the car.
4Brand data 35
| Brand | Code | Description | System |
|---|---|---|---|
| Ashok Leyland CV | P2251 | Leakage Or Misfiring In Cylinder 5 Brand | Powertrain |
| BAIC Motor | P2251 | O2 Sensor Negative Current Control Circuit/Open Bank 1 Sensor 1 Brand | Powertrain |
| Mercedes-Benz | P2251 | No description available | Powertrain |
| BYD | P2251 | O2 Sensor Negative Current Control Circuit/Open Bank 1 Sensor 1 Brand | Powertrain |
| Chery | P2251 | Oxygen (Lambda) Sensor B1 S1: Negative Lead: Open Circuit Brand | Powertrain |
| Daewoo | P2251 | O2 Sensor Ground Circuit Open Brand | Powertrain |
| Daihatsu | P2251 | A/F sensor B1S1- voltage Brand | Powertrain |
| DFFS | P2251 | The upstream oxygen sensor virtual ground circuit is open Brand | Powertrain |
| DFFX | P2251 | The upstream oxygen sensor line is open Brand | Powertrain |
| DFXK | P2251 | Oxygen (Lambda) Sensor B1 S1: Negative Lead: Open Circuit Brand | Powertrain |
| EOBD | P2251 | Syresensor negativ strömkontrollkrets/öppen bank 1 sensor 1 Brand | Powertrain |
| Geely | P2251 | Oxygen (Lambda) Sensor B1 S1: Negative Lead: Open Circuit Brand | Powertrain |
| GM | P2251 | O2 Sensor Negative Current Control Circuit/Open Bank 1 Sensor 1 Brand | Powertrain |
| Great Wall | P2251 | O2 Sensor Negative Current Control Circuit/Open Bank 1 Sensor 1 Brand | Powertrain |
| Hafei | P2251 | O2 Sensor Negative Current Control Circuit/Open Bank 1 Sensor 1 Brand | Powertrain |
| Holden | P2251 | HO2S Low Reference Circuit Sensor 1 Brand | Powertrain |
| Honda | P2251 | No description available | Powertrain |
| Hyundai | P2251 | No description available | Powertrain |
| Isuzu | P2251 | No description available | Powertrain |
| Land Rover | P2251 | No description available | Powertrain |
| Maserati | P2251 | Oxygen sensor negative current control circuit/open (bank 1 sensor 1) Brand | Powertrain |
| Mitsubishi | P2251 | O2S/LAFS(front) nega.current OPN Brand | Powertrain |
| Opel | P2251 | O2 Sensor Negative Current Control Circuit/Open Bank 1 Sensor 1 Brand | Powertrain |
| Perodua | P2251 | A/F sensor B1S1- voltage Brand | Powertrain |
| Peugeot | P2251 | No description available | Powertrain |
| Porsche | P2251 | No description available | Powertrain |
| Proton | P2251 | No description available | Powertrain |
| Saab | P2251 | O2 Sensor Negative Current Control Circuit/Open Bank 1 Sensor 1 Brand | Powertrain |
| MG (SAIC) | P2251 | O2 Sensor Negative Current Control Circuit/Open Bank 1 Sensor 1 Brand | Powertrain |
| Smart | P2251 | No description available | Powertrain |
| Sprinter | P2251 | No description available | Powertrain |
| Suzuki | P2251 | O2 Sensor Negative Current Control Circuit / Open Brand | Powertrain |
| Tata | P2251 | O2 Sensor Negative Current Control Circuit/Open Bank 1 Sensor 1 Brand | Powertrain |
| Toyota | P2251 | Upstream oxygen sensor negative current control circuit open Brand | Powertrain |
| Volkswagen | P2251 | Oxygen (Lambda) sensor B1 S1: negative Lead: open circuit; Defective Brand | Powertrain |
Legend: SAE is the generic J2012 description; Brand is text taken from that manufacturer’s data. Manufacturer rows keep the wording and language of the source data, and non-English text is tagged so screen readers pronounce it correctly.
5Extended variant codes 7
These 7-character codes are manufacturer-specific variants of P2251 and may be reported by some scan tools.
| Brand | Code | Description | System |
|---|---|---|---|
| Mercedes-Benz | P225100 | Der Anschluss der Signalrücklaufleitung der Lambdasonde 1 (Zylinderreihe 1) hat einen elektrischen Fehler oder Unterbrechung. Brand | Powertrain |
| Hyundai | P225100 | If open in virtual ground circuit of front lambda sensor is detected, ECM sets DTC Brand | Powertrain |
| SsangYong | P225100 | Front O2 Sensor Negative Current Control Open Circuit Brand | Powertrain |
| Mercedes-Benz | P225113 | Der Anschluss der Signalrücklaufleitung der Lambdasonde 1 (Zylinderreihe 1) hat einen elektrischen Fehler oder Unterbrechung. Es liegt eine Unterbrechung vor. Brand | Powertrain |
| Sprinter | P225113 | Der Anschluss der Signalrücklaufleitung der Lambdasonde 1 (Zylinderreihe 1) hat einen elektrischen Fehler oder Unterbrechung. Es liegt eine Unterbrechung vor. Brand | Powertrain |
| SsangYong | P225113 | WRAF open circuit failure on vm (during WRAF active state) Brand | Powertrain |
| SsangYong | P225115 | WRAF open circuit failure on vm (before WRAF init state) Brand | Powertrain |
6Related codes
Browse Pxxx codes or P225xx codes.