What Does P0AB7 Mean?
DTC P0AB7 indicates that the engine mount 'B' control circuit is reading low. Active engine mounts use electronically controlled fluid or vacuum actuators to counteract engine vibration, and this code means the control signal voltage has fallen below the expected operating range. This is typically caused by a short to ground in the mount solenoid circuit or a failed mount actuator. Excessive engine vibration transmitted to the cabin is the most common symptom.
Common Causes
30%
Short to ground in the engine mount 'B' solenoid control wire
28%
Failed active engine mount 'B' solenoid (internally shorted)
22%
Damaged wiring harness near the engine mount due to heat or vibration
12%
Corroded connector at the engine mount actuator
8%
Powertrain control module driver circuit failure
Diagnostic Steps
1
With the engine running, note if there is excessive vibration at idle or during specific RPM ranges (particularly the transition between EV and ICE modes on hybrids). Compare vibration levels with the mount commanded on versus off.
2
Locate the 'B' active engine mount and inspect its electrical connector for damage, corrosion, or loose pins. Check for oil contamination from a leaking mount.
3
Disconnect the mount solenoid and measure its resistance with a DVOM. Compare to the manufacturer's specification (typically 10-40 ohms). Also check for shorts to ground.
4
With the solenoid disconnected, measure the control signal voltage at the harness-side connector while commanding the mount on. If voltage is still low, the wiring has a short to ground.
5
Inspect the wiring harness for heat damage from the exhaust manifold or abrasion against engine components. Active mount wiring is particularly vulnerable to vibration-induced wear.
Estimated Repair Cost
$200 - $800
Parts + labor, varies by vehicle and location
DTC P0AB7 indicates that the engine mount 'B' control circuit is reading low. Active engine mounts use electronically controlled fluid or vacuum actuators to counteract engine vibration, and this code means the control signal voltage has fallen below the expected operating range. This is typically c...
The most common cause of P0AB7 (Engine Mount "B" Control Circuit Low) is: Short to ground in the engine mount 'B' solenoid control wire
Typical repair costs for P0AB7 range from $200 to $800, depending on the vehicle, location, and whether you do it yourself or go to a shop.
While not immediately dangerous, a non-functional active engine mount increases cabin vibration and can accelerate wear on other engine mounts and drivetrain components. On hybrid vehicles, excessive vibration during ICE-to-EV transitions can be particularly noticeable.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P0AB7 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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