P0429
PowertrainCatalystlow severityCatalyst Heater Control Circuit (Bank 1)
What P0429 Means
The PCM detected a fault in the bank 1 catalyst heater control circuit. The heater helps the converter reach operating temperature faster for emissions control.
Symptoms
- Check engine light on
- Failed emissions test
- Slow catalyst warm-up
Common Causes
- Faulty catalyst heater
- Open or shorted wiring
- Blown fuse or relay
- Faulty PCM driver
Diagnostic Steps
- Scan and confirm P0429
- Test heater circuit continuity
- Inspect wiring and fuse
- Verify PCM control signal
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