Drive Belts, Mounts, Brackets and Accessories: Testing and Inspection

Electro-Hydraulic Engine Mount Solenoid Valve, checking

Special tools, testers and auxiliary items required





^ Multimeter V.A.G 1526 B or V.A.G 1526 A
^ Voltage tester V.A.G 1527 B
^ Connector test kit V.A.G 1594 C or V.A.G 1594 A
^ Test box 1598/31
^ Vehicle Diagnostic, Testing and Information System VAS 5051 A with diagnostic cable VAS 5051/1

Work sequence
- Connect Vehicle Diagnostic, Testing and Information System VAS 5051 A and select vehicle system "01 - Engine electronics". Ignition must be switched on Guided Fault Finding in VAS 5051 A.





Display on VAS 5051 A:
- In selection - 1 -, click on function "03 - output Diagnostic Test Mode (DTM)".
- Press button repeatedly until Right Electro-Hydraulic Engine Mount Solenoid Valve -N145-.
^ Right Electro-Hydraulic Engine Mount Solenoid Valve -N145- is actuated in intervals (clicks) for about 1 minute.
- Press button repeatedly until Left Electro-Hydraulic Engine Mount Solenoid Valve N144 is actuated.
^ Left Electro-Hydraulic Engine Mount Solenoid Valve -N144- is actuated in intervals (clicks) for about 1 minute.
- End function "03 - output Diagnostic Test Mode (DTM)" by pressing button.
- Select "06 - End Output".
- Switch ignition off.
If one of the valves is not being actuated (does not click):





Electrical check for electro-hydraulic engine mount solenoid valves
- Remove quick-release screws - 1 -, remove screws - 2 - and remove sound insulation.





Checking internal resistance
- Disconnect electrical harness connector at respective solenoid valve - arrow -.
- Connect multimeter to valve for resistance measurement.
^ Specified value: 18 to 26

If specified value is not obtained:
- Replace solenoid valve.

If specified value is obtained:
- Check voltage supply.

Checking voltage supply
^ Fuse for electro-hydraulic engine mount solenoid valve OK. Electrical Wiring Diagrams, Troubleshooting Component Locations





- Connect voltage tester V.A.G 1527 B as follows:





- Switch ignition on.
^ LED must light up
- Switch ignition off.

If LED does not light up:
- Check wiring connection from terminal - 1 - of electrical harness connector via fuse to Motronic Engine Control Module (ECM) Power Supply Relay -J271- for open circuit according to wiring diagram.
- Repair wiring connection if necessary.

If LED lights up:
- Check actuation.

Checking actuation





- Connect voltage tester V.A.G 1527 B between terminals - 1 - and - 2 -.
^ Vehicle Diagnostic, Testing and Information System VAS 5051 A connected, "Vehicle Self-Diagnosis" "01 Engine electronics" selected. Ignition must be switched on.





Display on VAS 5051 A:
- In selection - 1 -, click on function "03 - output Diagnostic Test Mode (DTM)".
- Press button repeatedly until the Right Electro-Hydraulic Engine Mount Solenoid Valve -N145- is actuated.
^ LED must blink
- Press button repeatedly until the Left Electro-Hydraulic Engine Mount Solenoid Valve -N144- is actuated.
^ LED must blink
- End function "03 - output Diagnostic Test Mode (DTM)" by pressing button.
- Select "06 - End Output".
- Switch ignition off.

If LED does not blink or if it remains constantly lit:





- Connect test box V.A.G 1598/31 to wiring harness connectors, Engine Control Module (ECM) is not connected. Connect Ground (GND) clip at test box (not visible in illustration) to Ground (GND).

CAUTION: To avoid damaging electronic components, set measuring range before connecting test leads and observe all test requirements.





- Check following wiring connections for open circuit and short circuit to Ground (GND) and B+:
^ Left Electro-Hydraulic Engine Mount Solenoid Valve -N144-





^ Right Electro-Hydraulic Engine Mount Solenoid Valve -N145-





- Repair wiring connection if necessary. If wiring connection is OK:
- Replace Engine Control Module (ECM).

If no malfunctions are detected:
- Replace respective electro-hydraulic engine mount.