PowertrainP0686
SeriousSeverity: Serious - have it checked soon
ECM/PCM Power Relay Control Circuit Low
Key terms: Control module: a small computer that runs one part of the car · SAE J2012: the standard generic code list · Powertrain: engine, transmission and emissions
1What it means in plain English
The engine computer or one of its output circuits has a fault.
2Common causes
- Engine control module fault
- Power or ground connection problem
- Low battery or charging voltage
- Wiring short or open circuit
- Software or memory fault
3Can I drive?
If the engine runs normally, drive carefully to a workshop for diagnosis. If it runs badly, stalls, or will not restart, have the car towed.
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 32
| Brand | Code | Description | System |
|---|---|---|---|
| Ashok Leyland CV | P0686 | ECM/PCM Power Relay Control Circuit Low SAE | Powertrain |
| BAIC Motor | P0686 | Main relay circuit voltage low Brand | Powertrain |
| BYD | P0686 | Main relay circuit stuck closed Brand | Powertrain |
| Chery | P0686 | Main Relay Open Too Early Brand | Powertrain |
| Chrysler | P0686 | ECM/PCM Power Relay Control Circuit Low SAE | Powertrain |
| Daewoo | P0686 | Main Relay Malfunction Brand | Powertrain |
| DFFS | P0686 | Power relay control failure Brand | Powertrain |
| DFFX | P0686 | Main relay circuit stuck closed Brand | Powertrain |
| DFXK | P0686 | Main Relay, Premature Disconnect Fault Brand | Powertrain |
| EOBD | P0686 | Styrkrets ECM/PCM-strömrelä låg Brand | Powertrain |
| Geely | P0686 | Main relay circuit stuck closed Brand | Powertrain |
| GM | P0686 | ECM/PCM Power Relay Control Circuit Low Brand | Powertrain |
| Great Wall | P0686 | Main relay open too early Brand | Powertrain |
| Hafei | P0686 | Main relay circuit stuck closed Brand | Powertrain |
| Holden | P0686 | Engine Controls Ignition Relay Control Circuit Low Voltage Brand | Powertrain |
| Honda | P0686 | ECM/PCM Power Relay Control Circuit Low SAE | Powertrain |
| Hyundai | P0686 | ECM/PCM Power Relay Control Circuit Low SAE | Powertrain |
| Isuzu | P0686 | ECM/PCM Power Relay Control Circuit Low SAE | Powertrain |
| Land Rover | P0686 | ECM/PCM Power Relay Control Circuit Low SAE | Powertrain |
| Mahindra | P0686 | ECM/PCM Power Relay Control Circuit Low SAE | Powertrain |
| Maserati | P0686 | Engine Control Module Main Control Circuit Low Brand | Powertrain |
| Mitsubishi | P0686 | Fuel pump relay circuit low Brand | Powertrain |
| Opel | P0686 | ECM/PCM Power Relay Control Circuit Low Brand | Powertrain |
| Peugeot | P0686 | ECM/PCM Power Relay Control Circuit Low SAE | Powertrain |
| Porsche | P0686 | ECM/PCM Power Relay Control Circuit Low SAE | Powertrain |
| Proton | P0686 | Fuel pump relay circuit low Brand | Powertrain |
| Saab | P0686 | ECM/PCM Power Relay Control Circuit Low Brand | Powertrain |
| MG (SAIC) | P0686 | ECM/PCM Power Relay Control Circuit Low Brand | Powertrain |
| Suzuki | P0686 | ECM / PCM Power Relay Control Circuit Low Brand | Powertrain |
| Tata | P0686 | Main Relay Response Slow Brand | Powertrain |
| Toyota | P0686 | Fuel pump relay control circuit voltage low Brand | Powertrain |
| Volkswagen | P0686 | ECM power relay control circuit (J271): short to GND; Short to plus 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 1
These 7-character codes are manufacturer-specific variants of P0686 and may be reported by some scan tools.
| Brand | Code | Description | System |
|---|---|---|---|
| Mercedes-Benz | P068600 | The output for relay 'Circuit 87' has a short circuit to ground. Brand | Powertrain |
6Related codes
Browse Pxxx codes or P068xx codes.