Cause
Faulty active engine mount
A switchable engine mount that has stopped switching — stuck soft, stuck stiff, or leaking the vacuum or losing the solenoid that worked it. The consequence is always comfort, never reliability: shudder as the engine stops and starts, coarse idle vibration, a thump under hard acceleration.
On vacuum-operated designs, check the line before the mount. A split, perished or slipped vacuum hose produces exactly the same complaint and the same codes for pennies — and engine bay work is the classic disturber. The mount itself does wear out (its internal diaphragm or solenoid failing), but it is the second suspect, priced accordingly.
Typically a moderate job.
Codes this can cause (6)
Codes where this is a likely explanation first, rather than merely a possible one.
- P0A14 Engine Mount A Control Circuit/Open Likely for this code Low
- P0A15 Engine Mount A Control Circuit Low Likely for this code Low
- P0A16 Engine Mount A Control Circuit High Likely for this code Low
- P0AB6 Engine Mount B Control Circuit/Open Likely for this code Low
- P0AB7 Engine Mount B Control Circuit Low Likely for this code Low
- P0AB8 Engine Mount B Control Circuit High Likely for this code Low
Information, not instruction
CarGeek is a reference, not a service manual. Its pages are written from public sources and from what other people have found, never from a manufacturer's own service information, so they can be wrong or incomplete for your particular vehicle. Some of what they describe carries real risk: high voltage, fuel under pressure, stored energy, hot and moving parts.
Have anything you intend to act on checked by a trained person against the manufacturer's own procedure for your vehicle. Nothing here replaces that procedure.
Others who found this
Be the first to write this up
Nothing posted about this yet. Whatever you found is worth writing down — even a dead end saves someone the same afternoon.
What makes one worth reading:
- The car — make, model, year and engine. The same fault behaves differently on each.
- What you measured, not only what you replaced.
- What actually fixed it — or that nothing did, which is worth knowing too.
Sign in or create an account to add what you found about Faulty active engine mount.