What it means
The active engine mount B control circuit reports a control circuit/open condition. Vibration damping cannot be modulated.
At a glance
- Usually lights the check-engine light
How it works
Active engine mount B uses an electrically controlled actuator to change how much engine movement it absorbs. The control module monitors mount B's circuit for an open path; it sets P0AB6 when that circuit appears disconnected, so the mount's damping cannot be adjusted.
Common causes
Most likely first.
- Open in mount control wire
- Open mount actuator
- Pin pushed back out of connector body
Symptoms
- Check-engine light may illuminate
- Increased engine vibration, especially at idle
- Clunk or thump when starting, stopping, or shifting
How to diagnose it
- Record freeze-frame data and check whether the fault returns at idle or during a start, stop, or gear change.
- With the engine off, inspect mount B's connector for a pushed-back pin, poor seating, damage, or corrosion.
- Inspect the harness from mount B for breaks, chafing, or a pulled wire that could interrupt the circuit.
- Using the vehicle wiring diagram, check continuity through the mount B control wires and connectors for an open.
- If the wiring and connections are intact, test the mount B actuator and control-module output according to the manufacturer's specification.
Common fixes
- Reseat the mount B connector and secure its terminals.
- Repair an open or damaged wire in the mount B control circuit.
- Replace a damaged connector or terminal, including a pushed-back pin.
- Replace the mount B actuator if it fails the specified test.
Can I keep driving?
If vibration or clunking is mild, a short, gentle drive to a repair location may be possible, but avoid hard acceleration and abrupt gear changes. Stop if engine movement becomes severe, as it can strain mounts and nearby components.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.