P1658
Electronic Throttle Control System Control Relay ON Malfunction
Severity
⚠️ MediumCan you drive?
Limited driving only, diagnose soon
Approx. repair cost
$6–22 (est.)
Symptoms
- Reduced engine power
- Unstable idle speed
- Check Engine Light Illuminates
- The car goes into emergency mode
- Acceleration problems
Causes
- Faulty throttle control relay
- Problems with wiring or relay contacts
- Short circuit in control circuit
- Engine control unit (ECU) malfunction
- Corrosion or oxidation of relay contacts
How to Fix
- Check the condition of the throttle control relay
- Inspect wiring and connectors for damage
- Check the voltage on the relay and its circuits
- Replace relay if necessary
- Test the system after repair