P0687
Engine Control Module Voltage Error High
Generic code
Computer Output Circuit
High severity
Hard repair
Free on OBD DashX
Want real-world data on P0687?
See which problems come with P0687, how often it shows up in other vehicles, and how to fix it — step by step.
- Real-world fix data
- How often it happens
- Step-by-step repairs
What P0687 means
- The fault code P0687 indicates that there is an issue with the power relay control circuit for the engine control module/ powertrain control module, which is causing the voltage to be higher than the normal range. This may cause the engine to run poorly or not start at all.
Possible symptoms
- Engine runs poorly or not at all
- Illuminated check engine light
- Reduced engine power or acceleration
Possible causes
- Faulty power relay
- Faulty wiring or connections in the circuit
- Loose or corroded electrical connections
- Failed engine control module (ECM)/powertrain control module (PCM)
Related parts
- Engine Control Module (ECM): ECM is the part of the car computer that controls the engine system and performance. Problems lead to poor fuel economy, engine stalling & unwanted engine vibrations
Possible solutions
- Replace the power relay
- Check and repair any damaged wiring or connections
- Tighten or clean any loose or corroded electrical connections
- Replace the engine control module (ECM)/powertrain control module (PCM) if necessary
Free on OBD DashX
P0687 on OBD DashX
Real-world causes, how often this code shows up, and the fix — step by step.
Open P0687 No sign-up needed · available in 10 languagesScan your own car
Read and clear fault codes, live data and service resets with the CaRPM app.