|P0012 – Intake Camshaft Position Timing – Over-Retarded (Bank 1)|
|Description: The powertrain control module (PCM) monitors the variable camshaft timing (VCT) position for over-retarded camshaft timing. The test fails when the camshaft timing exceeds a maximum calibrated value or remains in a retarded position.
Possible Causes: • Camshaft timing incorrectly set
• Continuous oil flow to the VCT piston chamber
• Erratic camshaft position due to low oil pressure
• Oil flow restriction in the oil passages or the VCT valve body
• VCT solenoid valve stuck open
• Open or short in the VCT circuit
• Open VPWR circuit
• Camshaft advance mechanism binding (VCT unit)
• Damaged VCT phaser
• Damaged camshaft position (CMP) sensor
• Open or short in the CMP sensor circuits
• Radio frequency interference (RFI)
Diagnostic Aids: These DTCs may be accompanied by other DTCs. Diagnose all CMP sensor DTCs first. If no CMP sensor related DTCs are present, continue to follow diagnosis for the DTC.
This DTC is a functional check of the VCT unit. Diagnose any base engine concerns related to the engine oil pressure or engine timing. Refer to the Workshop Manual Section 303-00, Engine System, Oil Pressure Test, to check the engine oil pressure. Refer to the Workshop Manual Section 303-01, Engine, Timing Drive Components, to check the engine timing and VCT phasers.