PowertrainP0139
CautionSeverity: Caution - get it checked when you can
O2 Sensor Circuit Slow Response (Bank 1 Sensor 2)
Key terms: Oxygen sensor: measures oxygen in the exhaust gas · Mass air flow sensor: measures the air going into the engine · Bank 1: the side of the engine containing cylinder 1 · SAE J2012: the standard generic code list · Powertrain: engine, transmission and emissions
1What it means in plain English
This code is in the fuel, air and oxygen sensor range, which also includes coolant temperature faults.
2Common causes
- Dirty or faulty mass air flow sensor
- Vacuum or intake air leak
- Weak fuel pump or clogged fuel filter
- Faulty fuel injector
- Faulty oxygen sensor
- Wiring or connector fault
3Can I drive?
Have it diagnosed if the engine runs badly or the code keeps returning. Because this range includes coolant temperature sensors, watch the temperature gauge: if it climbs into the red, or the engine overheats or stalls, stop safely and get professional help.
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 41
| Brand | Code | Description | System |
|---|---|---|---|
| Ashok Leyland CV | P0139 | Injector Supply Voltage. Group 5. High Signal Brand | Powertrain |
| BAIC Motor | P0139 | Downstream oxygen sensor response too slow Brand | Powertrain |
| Mercedes-Benz | P0139 | O2 Sensor Circuit Slow Response (Bank 1 Sensor 2) SAE | Powertrain |
| BMW | P0139 | Sensor too slow Brand | Powertrain |
| BYD | P0139 | O2 sensor signal stuck rich Brand | Powertrain |
| Chery | P0139 | Rear oxygen signal diagnosis Brand | Powertrain |
| Daewoo | P0139 | O2 Sensor Circuit Slow Response Bank 1 Sensor 2 Brand | Powertrain |
| DFFS | P0139 | Downstream oxygen sensor signal failure Brand | Powertrain |
| DFFX | P0139 | Oxygen sensor slow resp. Brand | Powertrain |
| DFXK | P0139 | Downstream oxygen sensor reaction aging Brand | Powertrain |
| EOBD | P0139 | O2-sensorcircuit trage respons bank 1 sensor 2 Brand | Powertrain |
| Ford | P0139 | O2 Sensor Circuit Slow Response (Bank 1 Sensor 2) SAE | Powertrain |
| Geely | P0139 | Oxygen sensor slow resp. Brand | Powertrain |
| GM | P0139 | Respuesta Lenta HO2S 2 Bnc.1 Brand | Powertrain |
| Great Wall | P0139 | Oxygen sensor slow resp. Brand | Powertrain |
| Hafei | P0139 | Oxygen sensor slow resp. Brand | Powertrain |
| Holden | P0139 | HO2S Slow Response Sensor 2 Brand | Powertrain |
| Honda | P0139 | O2 Sensor Circuit Slow Response (Bank 1 Sensor 2) SAE | Powertrain |
| Hyundai | P0139 | O2 Sensor Circuit Slow Response (Bank 1 Sensor 2) SAE | Powertrain |
| Isuzu | P0139 | O2 Sensor Circuit Slow Response (Bank 1 Sensor 2) SAE | Powertrain |
| Land Rover | P0139 | O2 sensor circuit slow response Brand | Powertrain |
| Mahindra | P0139 | O2 Sensor Circuit Slow Response (Bank 1 Sensor 2) SAE | Powertrain |
| Maserati | P0139 | O2 Sensor Circuit Slow Response (Bank 1 Sensor 2) SAE | Powertrain |
| Mazda | P0139 | O2 Sensor Circuit Slow Response (Bank 1 Sensor 2) SAE | Powertrain |
| Mitsubishi | P0139 | Oxygen sensor(rear) response Brand | Powertrain |
| Nissan | P0139 | Heated oxygen sensor 2 Brand | Powertrain |
| Opel | P0139 | Respuesta Lenta HO2S 2 Bnc.1 Brand | Powertrain |
| Peugeot | P0139 | O2 Sensor Circuit Slow Response (Bank 1 Sensor 2) SAE | Powertrain |
| Porsche | P0139 | Lambda-Sonde nach Kat Bank 1: Signal zu langsam Brand | Powertrain |
| Proton | P0139 | O2 Sensor Circuit Slow Response (Bank 1 Sensor 2) SAE | Powertrain |
| Renault | P0139 | O2 Sensor Circuit Slow Response (Bank 1 Sensor 2) SAE | Powertrain |
| Saab | P0139 | Respuesta Lenta HO2S 2 Bnc.1 Brand | Powertrain |
| MG (SAIC) | P0139 | O2 Sensor Circ.,Bank1-Sensor2 Slow Response Brand | Powertrain |
| Smart | P0139 | O2 Sensor Circuit Slow Response (Bank 1 Sensor 2) SAE | Powertrain |
| Sprinter | P0139 | O2 Sensor Circuit Slow Response (Bank 1 Sensor 2) SAE | Powertrain |
| Subaru | P0139 | O2 Sensor Circuit Slow Response Brand | Powertrain |
| Suzuki | P0139 | O2 Sensor Circuit Slow Response (Bank1 Sensor2) Brand | Powertrain |
| SWM Motor | P0139 | Downstream oxygen sensor response is too slow Brand | Powertrain |
| Tata | P0139 | Oxygen Sensor 2 Brand | Powertrain |
| Toyota | P0139 | The downstream oxygen sensor responds slowly Brand | Powertrain |
| Volkswagen | P0139 | Oxygen (Lambda) sensor B1 S2: response too slow 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 3
These 7-character codes are manufacturer-specific variants of P0139 and may be reported by some scan tools.
| Brand | Code | Description | System |
|---|---|---|---|
| SsangYong | P013900 | Rear O2 sensor circuit slow response Brand | Powertrain |
| Mercedes-Benz | P013902 | Die Lambdasonde 2 (Zylinderreihe 1) reagiert verzögert.Es liegt ein allgemeiner Signalfehler vor. Brand | Powertrain |
| Mercedes-Benz | P013926 | Die Lambdasonde 2 (Zylinderreihe 1) reagiert verzögert.Signaländerungsrate ist unterhalb des zulässigen Grenzwertes. Brand | Powertrain |
6Related codes
Browse Pxxx codes or P013xx codes.