P0024Powertrain
Powertrain · SAE
'B' Camshaft Position – Timing Over-Retarded (Bank 2)
Meaning
The variable valve timing (VVT) system has detected that the exhaust camshaft on bank 2 is retarded beyond the commanded target. The ECM commands a specific phaser position and detects an excessive deviation toward retard. This fault can impair exhaust valve timing and overall engine performance.
Common causes
- Depleted, contaminated, or incorrect viscosity engine oil reducing hydraulic pressure to the phaser
- Stuck or faulty oil control valve (OCV) locked in the retard position
- Mechanically seized cam phaser stuck in the retarded position
- Timing chain stretch or excessive wear causing phase loss
- Insufficient oil pressure due to pump failure or internal leakage
- Damaged or shorted wiring or connector at the OCV
Symptoms
- Malfunction indicator lamp (MIL) illuminated
- Reduced engine performance and torque, especially at mid-range RPM
- Increased fuel consumption
- Difficult or rough engine start
- Metallic rattling noise from the timing chain area on cold start
- Exhaust emissions exceeding limits
Severity
Medium to high severity: if neglected, a stuck phaser can damage the timing chain and lead to permanent engine damage.
What to do
- Check engine oil level and condition; replace with the specified viscosity if depleted or contaminated
- Measure actual oil pressure with a mechanical gauge
- Electrically test the bank 2 OCV (resistance, supply voltage, control signal)
- Perform an actuator test with a scan tool to verify phaser response
- If the timing chain is stretched or the phaser is mechanically faulty, replace the affected components