P1800high severityPowertrain
Transmission Control Relay Circuit
on 2023 Chevrolet Bolt EUV 65 kWh Single Motor FWD · FWD
What this code means
A fault was detected in the transmission control relay circuit. This can cut power to transmission solenoids.
Symptoms
- No shifting or stuck in gear
- Transmission warning light
- Limp mode
Common causes
- Faulty transmission control relay
- Wiring open or short
- Corroded relay socket
- Faulty TCM driver
Diagnostic steps
- Test relay operation and coil
- Inspect relay circuit wiring
- Check power to solenoids
- Replace relay or repair wiring
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