What Does P0AB8 Mean?
DTC P0AB8 indicates that the engine mount 'B' control circuit is reading high. The control signal voltage for the active engine mount actuator has exceeded the expected range, typically indicating an open circuit condition or a short to battery voltage in the solenoid control wire. The active mount system cannot dampen engine vibration properly, and the mount will default to its passive (non-energized) state.
Common Causes
30%
Open circuit in the engine mount 'B' solenoid control wire
25%
Failed active engine mount 'B' solenoid (open coil)
22%
Disconnected or backed-out connector pin at the mount actuator
13%
Short to battery voltage in the control circuit
10%
Powertrain control module output driver fault
Diagnostic Steps
1
Observe engine vibration characteristics at idle and during RPM changes. An inoperative active mount typically causes a pronounced vibration shudder, especially during engine start/stop events on hybrid vehicles.
2
Inspect the connector at the 'B' active engine mount for disconnection, backed-out terminals, or corrosion. These mounts are in a high-vibration environment and connectors can work loose over time.
3
Measure the solenoid coil resistance. An open reading (OL) indicates the mount solenoid has failed and the mount assembly needs replacement.
4
Check for continuity in the control wire from the PCM to the mount connector. Also check for shorts to B+ voltage that could drive the signal high.
5
If the wiring and mount solenoid test good, command the mount actuator on and off using the scan tool while monitoring the circuit voltage at the PCM connector to verify the module's driver circuit is functioning.
Estimated Repair Cost
$200 - $850
Parts + labor, varies by vehicle and location
DTC P0AB8 indicates that the engine mount 'B' control circuit is reading high. The control signal voltage for the active engine mount actuator has exceeded the expected range, typically indicating an open circuit condition or a short to battery voltage in the solenoid control wire. The active mount ...
The most common cause of P0AB8 (Engine Mount "B" Control Circuit High) is: Open circuit in the engine mount 'B' solenoid control wire
Typical repair costs for P0AB8 range from $200 to $850, depending on the vehicle, location, and whether you do it yourself or go to a shop.
A failed active engine mount increases NVH (noise, vibration, harshness) levels in the cabin but does not pose an immediate safety risk. However, prolonged operation with a failed mount can stress adjacent mounts and drivetrain components, potentially leading to premature failure.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P0AB8 to identify the root cause.
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Quick Info
Category
Powertrain
System
Engine Mount / NVH Control
Difficulty
Type
Generic (SAE)
Recommended Tools
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