P1643moderate severityPowertrain
Engine Speed Output Circuit
on 2023 Chevrolet Bolt EUV 65 kWh Single Motor FWD · FWD
What this code means
The PCM detected a fault in the engine speed output circuit sent to other modules. This can affect components that rely on RPM signals.
Symptoms
- Check engine light on
- Tachometer erratic or dead
- Related module faults
Common causes
- Wiring or connector fault
- Short or open in output circuit
- Faulty receiving module
- Faulty PCM
Diagnostic steps
- Check engine speed output wiring
- Test signal at receiving module
- Inspect connectors for damage
- Repair circuit or replace PCM
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