Advanced Diagnostics

Advanced Diagnostics

DTC P0AB7: Rear Engine Mount Actuator Control Circuit Low Current (ACM System)







General Description
The engine mount control system controls the engine mounts electronically. The system consists of the active control engine mount (ACM) actuators, the engine mount control unit, and the powertrain control module (PCM). The engine mount control unit uses the crankshaft and camshaft position sensor outputs (received from the PCM) to estimate engine vibration. The engine mount control unit then sends signals to the ACM actuators to command the engine mounts to push and pull on the engine to counteract the engine vibration. The PCM monitors the rear ACM actuator, and when an abnormal condition continues for a set time, the PCM detects a malfunction and a DTC is stored.

Monitor Execution, Sequence, Duration, DTC Type, OBD Status







Enable Conditions







Malfunction Threshold
The duty cycle of the rear ACM actuator, which outputs in 1 TDC duration as one cycle, reads 100 % all the time during engine mount operation and continues at least 20 seconds.

Driving Pattern
Start the engine, and let it idle for at least 20 seconds.

Diagnosis Details

Conditions for illuminating the indicator
When a malfunction is detected, the DTC and the freeze frame data are stored in the PCM memory. The MIL does not come on.

Conditions for clearing the DTC
The DTC and the freeze frame data can be cleared by using the scan tool Clear command or by disconnecting the battery.