DTC P15AB
DTC P15AB: Engine Mount Control Unit Power Source Circuit Low Voltage
General Description
The engine mount control system controls the engine mounts electronically. The system consists of the engine mount 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 engine mount actuators to command the engine mounts to push and pull on the engine to counteract engine vibration. The engine mount control unit monitors the IG1 ACM (DC/DC) terminal voltage. If the IG1 ACM (DC/DC) terminal voltage is not within the set value for a set time, the engine mount control unit detects a malfunction and stores a DTC.
Monitor Execution, Sequence, Duration, DTC Type
| Execution | Continuous |
| Sequence | None |
| Duration | 20 seconds or more |
| DTC Type | One drive cycle, MIL off |
Enable Conditions
| Condition | |
|---|---|
| Vehicle | ON mode |
Malfunction Threshold
The IG1 ACM (DC/DC) terminal voltage [ACM UNIT SUPPLY VOLTAGE] is 4.0 V or less for at least 20 seconds.
[ ]: HDS Parameter
Possible Cause
NOTE: The causes shown may not be a complete list of all potential problems, and it is possible that there may be other causes.
- Engine mount control unit IG1 ACM (DC/DC) line open (include fuse blown)
- Engine mount control unit IG1 ACM (DC/DC) line short to ground
- Active control engine mount (ACM) control relay stuck on
- Engine mount control unit internal circuit failure
Diagnosis Details
Conditions for setting the DTC
When a malfunction is detected, a Pending DTC, a Confirmed DTC, and the freeze data are stored in the PCM. The MIL does not come on.
Conditions for clearing the DTC
The Pending DTC, the Confirmed DTC, and the freeze data can be cleared with the scan tool Clear command or by disconnecting the 12 volt battery.