P0AB6
Engine Mount B Control Circuit/Open.
- Generic
- Powertrain
- Generic code
- Low severity
How this code is built
- P
- SystemPowertrain
- 0
- Defined bySAE, the same on every car
- A
- AreaHybrid propulsion
- B6
- FaultThe specific fault in that area
What it means
P0AB6 means the control unit has detected an open circuit or no continuity in the control circuit for engine mount B, an electronically controlled (active or switchable) engine mount. The module commands the mount actuator, usually a solenoid or valve, and sees a circuit state that doesn't match what it expects, such as an open circuit. Which mount is 'B' and how it is controlled depends on the vehicle and engine, so check the model-specific information.
Symptoms
- Warning light on, or a powertrain or hybrid system message
- More vibration or shake at idle, especially in gear with the engine running
- Increased engine vibration or noise at certain speeds or during start-up and shut-down
- Rough or shuddering feel as the engine starts or stops (on vehicles with stop-start or hybrid systems)
- Possible harshness through the steering wheel, seat or floor
- No noticeable change in some cases, with only the stored code present
Possible causes
- Damaged, chafed or broken wiring in the engine mount B control circuit, often caused by engine movementlikely
- Corroded, loose or pushed-out pins in the mount actuator connector or control module connectorlikely
- Faulty engine mount B actuator or solenoid with an open internal coillikely
- Blown fuse or loss of power or earth supply to the mount control circuitpossible
- Fault in the control module driver for the mount circuitrare
- Software issue where the manufacturer has issued a calibration update for this code on that modelrare
How to diagnose
- Read all stored and pending codes and note the freeze frame data, then check for other related codes such as other mount, power supply or communication faults.
- Check for any technical service bulletins or known issues for the specific model and engine, as mount layout and control method vary.
- Visually inspect the engine mount B wiring, harness routing and clips for chafing, stretching, heat damage or fluid contamination, particularly where the engine moves.
- Inspect the actuator and control module connectors for corrosion, water ingress, bent or loose pins, and poor locking.
- Check the relevant fuse and the power and earth supplies to the mount circuit using the wiring diagram.
- With the ignition off and the connector disconnected, measure the actuator coil resistance and compare it with the specification for the vehicle.
- Check circuit continuity between the control module and actuator, and test for shorts to earth or supply.
- Operate the mount using the bidirectional test function if available, and confirm actuator response and that the code does not return.
How to fix
- Repair or replace the damaged section of wiring, securing it correctly clear of moving parts and heat.
- Clean, repair or replace corroded or damaged connectors and terminals, ensuring they lock securely.
- Replace the engine mount or its actuator if the coil is open or it fails the operation test.
- Restore the power or earth supply and replace the blown fuse after finding the cause of the failure.
- Replace or repair the control module only after the wiring and actuator are proven good and the manufacturer's procedure calls for it.
- Apply a manufacturer calibration update only if one is published for this fault on the vehicle.
Can I keep driving?
The car can usually be driven carefully while you book it in, as this is mainly a comfort and vibration issue. If vibration becomes severe, or you notice excessive engine movement or other warning lights, have it checked sooner.
Guide written by AI from the code's definition. Confirm with a diagnosis before replacing parts.