Cylinder 9 Exhaust Valve Control Circuit Low
This code means the PCM/ECM has detected a low-voltage control circuit condition affecting cylinder 9 exhaust valve. On engines that use variable valve timing or cylinder deactivation, this can interfere with normal valve operation and may cause rough running, reduced fuel economy, or poor performance.
What You Might Notice
- Check Engine Light illuminated
- Rough idle or vibration
- Reduced engine performance
- Poor fuel economy
- Possible misfire or valvetrain noise
Most Common Causes
- 1
Short to ground or excessive resistance in the circuit
- 2
Dirty, low, or incorrect engine oil
- 3
Damaged wiring or corroded connector
- 4
Mechanical timing or valvetrain problem
- 5
PCM/ECM fault
How to Diagnose It
- 1
Check Short to ground or excessive resistance in the circuit — Inspect for signs of failure and test before replacing.
- 2
Check Dirty, low, or incorrect engine oil — Inspect for signs of failure and test before replacing.
- 3
Check Damaged wiring or corroded connector — Inspect for signs of failure and test before replacing.
- 4
Check Mechanical timing or valvetrain problem — Inspect for signs of failure and test before replacing.
- 5
Check PCM/ECM fault — Inspect for signs of failure and test before replacing.
How to Fix It
- 1
Check engine oil level/condition and correct it if needed
- 2
Inspect and repair wiring/connectors to the affected solenoid or switch
- 4
Verify mechanical timing or valvetrain condition
- 5
Clear the code and confirm normal operation with scan data
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