Complaint
The customer says that the check engine light is on and that the vehicle vibrates at idle.
Cause
The customer’s complaint is confirmed, with the vehicle vibrating at idle, but the vibration was not felt at high speeds. A scan tool found code P1573 – Left Engine Mount Solenoid Valve (N144) Open Circuit (17981). A visual inspection of the engine mount solenoid after raising the vehicle found no obvious faults.
At idle, a multimeter was used to check for the presence of voltage at the engine mount solenoid and ground from the engine control module (ECM), and found both were present. The multimeter was also used to measure the resistance of the engine mount solenoid and found that the measured resistance was out of specifications.
The results of these tests verified the engine mount solenoid was faulty. The engine mount solenoid is integrated into the engine mount and is replaced as an entire unit.
Correction
The engine mount was replaced, codes were cleared, and a road test was performed to verify that the vehicle operated properly. The check engine light did not illuminate and no fault codes returned.
Vehicle: 2006, Audi A4 Quattro, 2.0-L
Courtesy of Mitchell1’s SureTrack Real Fixes.