P0690
PowertrainPcm Powermoderate severityECM/PCM Power Relay Sense Circuit High
What P0690 Means
The PCM detected a high voltage on the power relay sense circuit when it should be low. This usually means the main power relay is staying energized or there is a wiring fault feeding voltage back to the PCM.
Symptoms
- Check engine light on
- Hard starting or no start
- Battery drain when parked
Common Causes
- Faulty main/ECM power relay
- Short to voltage in sense circuit wiring
- Corroded or damaged relay connector
- Failed PCM
Diagnostic Steps
- Scan and record freeze frame data
- Inspect power relay and connector for corrosion
- Test relay operation and sense circuit voltage
- Check wiring for short to power
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✓ Autel official store
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