Engine Mount Control Circuit Low
The P0AB7 code indicates that the Powertrain Control Module (PCM) has detected a low voltage condition in the control circuit of the active engine mount system. This system uses electronically controlled mounts to reduce engine vibrations. A low circuit voltage typically points to a wiring issue, a faulty mount solenoid, or a PCM problem. This can lead to increased vibrations and potential drivability concerns.
1. Symptoms You Will Notice
- Check Engine Light on
- Excessive engine vibration at idle or during acceleration
- Clunking noise from engine bay
- Reduced fuel economy
2. Most Common Causes
- Faulty electronic or hydraulic engine mount B
- Short to ground in the control circuit wiring
- Open electrical connection or loose terminals at the mount connector
- Broken wiring or damaged insulation
- Failed powertrain control module (PCM/ECM)
- Blown fuse or relay for the engine mount system
3. Step-by-Step Diagnosis
Step 1: Use a scan tool to confirm P0AB7 and check for related codes.
Step 2: Visually inspect the engine mount wiring and connector for damage, corrosion, or loose pins.
Step 3: Test the mount solenoid resistance with a multimeter (specs vary by vehicle, typically 10-30 ohms).
Step 4: Check for voltage and ground at the mount connector with the engine running.
Step 5: If wiring and mount test OK, suspect a PCM fault; perform a PCM update or replacement if necessary.
4. Frequently Asked Questions
Is it safe to drive with this code?▼
It is generally safe for short trips, but excessive vibration can cause damage to other components over time. Have it diagnosed promptly.
How much does it cost to fix?▼
Repair costs range from $150 to $400, depending on the cause. A simple wiring fix may be under $200, while replacing an engine mount can cost $300-$400 including labor.
5. Commonly Affected Makes
This is a generic OBD2 code, potentially applicable to any manufacturer using this diagnostic standard.