P1AB7 BMW Fault Code

Description:

Variable Cam Timing Over-advanced (Bank 1) The comprehensive component monitor (CCM) monitors the VCT position for an over-advanced camshaft timing.
The test fails when the camshaft timing exceeds a maximum calibrated value or remains in an advanced position.

BMW cam timing improperly set No oil flow to the VCT piston chamber Low oil pressure VCT solenoid valve stuck closed Camshaft advance mechanism binding (VCT unit) P1AB7 DTC is a check of the VCT unit.

P1AB7 Code Symptoms :

If your vehicle failed a P1AB7 test and the P1AB7 Check Engine Light is NOT on, chances are you have a problem with the OBDII system, a burned out MIL lamp, or a faulty catalytic converter. The converter is essentially an afterburner that cleans up the exhaust after it exits the engine. The OBDII system uses P1AB7 a ownstream oxygen sensor to monitor the efficiency of the converter, and it should detect a drop in converter efficiency if the converter has been contaminated or is failing (ignition misfiring, leaky exhaust valves, and oil burning can all damage the converter). What you want to look : Any conditions that might cause ignition misfire, an overly rich or lean fuel condition, or loss of compression.

Diagnosis And Repairing P1AB7

P1AB7 OBD2 may also be triggered by faults earlier down the line. For example, a dirty MAF sensor might be causing the car to overcompensate in its fuel-trim adjustments. As a result, oxygen sensors are likely to report fuel mixture problems.

How to fix P1AB7 code ?

• Erratic camshaft position due to low oil pressure
• Faulty Mass Air Flow (MAF) sensor
• Faulty Air fuel ratio (A/F) Sensor 1 Bank 1
• Open VPWR circuit

In most cases, the TCM is integrated into a single housing with the BMW PCM. Nevertheless, the section of the module which controls (automatic) transmission function may be powered up separately.

In any case, the TCM is typically powered using switched (only present with the ignition switch in the ON, start, or run position) voltage. This circuit is normally equipped with a fuse, fusible link, and/or a relay. Frequently, the PCM and TCM are powered using the same relay albeit by separate circuits. Access to a reliable vehicle information source will yield necessary details of the TCM power circuit for the specific vehicle in question.