Manifold Absolute Pressure Sensor, Checking

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) (J623) 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 (GND) 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 specification is not obtained:

- End diagnosis and switch ignition off.

Test procedure

- Perform a preliminary check to verify the customers complaint. Refer to => [ Preliminary Check ] Preliminary Check.

Start diagnosis

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





- 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: 4.5 V

- Switch the ignition off.

If the specification is not obtained:

Checking wiring

If the manufacturers test box is being used. Perform the following step.

- Install the Adapter Cable (121 Pin) (VAG1598/31 ).

If the manufacturers test box is not being used. Perform the following step.

- Remove the Engine Control Module (ECM) (J623). Refer to => [ Motronic Engine Control Module, Replacing ] Motronic Engine Control Module, Replacing.

- Using a multimeter, check the Manifold Absolute Pressure (MAP) Sensor (G71) electrical harness connector terminals to the Motronic Engine Control Module (ECM) (J220) electrical harness connector T121 terminals for an open circuit.









Specified value: 1.5 ohms max.

If the specification is not obtained:

- Check the wiring for a short circuit to each other, Battery (+), and Ground (GND).

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

- If necessary, repair the faulty wiring connection.

If no malfunction is detected in the wiring and if the voltage supply was OK:

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

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

- Erase the DTC memory. Refer to => [ Diagnostic Mode 04 - Erase DTC Memory ] Diagnostic Mode 04 - Erase DTC Memory

- Perform a road test to verify repair.

If the DTC does not return:

Repair complete, Generate readiness code. Refer to => [ Readiness Code ] Readiness Code.

- End diagnosis.

If the DTC does return and no malfunction is detected in the wiring and the voltage supply was OK:

- Replace the Motronic Engine Control Module (ECM) (J623). Refer to => [ Motronic Engine Control Module, Replacing ] Motronic Engine Control Module, Replacing.

- Assembly is performed in the reverse of the removal.

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 Mode 03 - Read DTC Memory.

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

3. If the DTC memory was erased, generate readiness code. Refer to => [ Readiness Code, Setting ] Readiness Code, Setting.

End of Diagnosis.