ECM/PCM Power Relay Sense Circuit Range/Performance
The voltage reported on the main power relay sense line for the engine controller does not match expectation. The ECU may shut down too early or stay awake too long, draining the battery.
Affected components
- Main relay
- Ecm
Common causes
- High likelihood: Main relay contacts pitted
- Medium likelihood: Sense wiring corroded
- Low likelihood: Sensor element aged beyond calibration window
Diagnostic notes
- The malfunction indicator lamp may illuminate
Sources
Diagnostic information is provided for reference only. Confirm the code with a compatible scan tool and follow the vehicle manufacturer's service procedures before replacing components.