Manifold Pressure/Vacuum Sensor: Testing and Inspection

Manifold Absolute Pressure Sensor, Checking

• Use only gold-plated terminals when servicing terminals in harness connector of Manifold Absolute Pressure (MAP) Sensor (G71).

Special tools, testers and auxiliary items required

• Multimeter.

• Wiring diagram.

Test conditions

• The Engine Control Module (ECM) (J220) OK.

• The parking brake must be applied, otherwise daytime running lights are switched on.

• On vehicles with automatic transmission, selector lever must be in position "P" or "N".

• The ground connections between engine and body must be OK.

Function test

- Connect the scan tool.

- Start engine and let it run at idle.

- Using the scan tool, Check the specified value of the Manifold Absolute Pressure (MAP) Sensor (G71) at idle:






If the specified value was obtained:

- Condition is not present at this time. Check connections for loose or damaged terminals and check harness for an intermittent short.

If the specified value was Not obtained:

Test sequence

- Disconnect the Manifold Absolute Pressure (MAP) Sensor (G71) electrical harness connector.

- Start the engine and run at idle speed.

- Using a multimeter, check the Manifold Absolute Pressure (MAP) Sensor (G71) electrical harness connector terminals 1 to 3 for voltage.

Specification: above 4.4 V

- Using a multimeter, check the Manifold Absolute Pressure (MAP) Sensor (G71) electrical harness connector terminals 1 to 4 for voltage.

Specification: above 4.8 V

- Switch the ignition OFF.

If the specified values were obtained:

- Replace Manifold Absolute Pressure (MAP) Sensor (G71).

If the specified values were Not obtained:

Checking wiring

- Remove the Engine Control Module (ECM) (J220). Refer to the Repair Information.

- Using a multimeter, check the Manifold Absolute Pressure (MAP) Sensor (G71) electrical harness connector to the Engine Control Module (ECM) (J220) electrical harness connector T60 for resistance. Refer to Wiring Diagrams for pin locations.






Specified Value: 1.5 ohm max.

If the specified value was Not obtained:

- Check the wiring for an open circuit, high resistance, short circuit to each other, Battery (+) or Ground.

- Check the electrical harness connector for damage, corrosion, loose or broken terminals.

- If necessary, repair the faulty wiring connection.

Specified value: 1.5 ohms max.

If no malfunction is detected in the wiring and the voltage supply was Not OK:

- Replace the Motronic Engine Control Module (ECM) (J220). Refer to the Repair Information.

Final procedures

After the repair work, the following work steps must be performed in the following sequence:

1. Check the DTC memory. Refer to => [ Diagnostic Mode 03 - Read DTC Memory ] Diagnostic Modes 01 - 09.

2. If necessary, erase the DTC memory. Refer to => [ Diagnostic Mode 04 - Erase DTC Memory ] Diagnostic Modes 01 - 09.

3. If the DTC memory was erased, generate readiness code. Refer to => [ Readiness Code ] Monitors, Trips, Drive Cycles and Readiness Codes.