P0419
PowertrainSecondary Airlow severitySecondary Air Injection System Relay B Circuit Malfunction
What P0419 Means
The PCM detected a fault in the secondary air injection pump relay B circuit. This relay controls power for the air pump during warm-up.
Symptoms
- Check engine light on
- Air pump inoperative
- Failed emissions test
Common Causes
- Faulty relay B
- Open or shorted wiring
- Blown fuse
- Faulty PCM driver
Diagnostic Steps
- Scan and confirm P0419
- Test relay B operation
- Inspect wiring and fuse
- Check PCM control output
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