Manifold Pressure/Vacuum Sensor: Testing and Inspection

Manifold Absolute Pressure Sensor, Checking

The Manifold Absolute Pressure (MAP) and Intake Air Temperature (IAT) sensors are located inside the same housing and cannot be serviced separately. Replacing one replaces the other.

Test requirements

• The Diesel Direct Fuel Injection (DFI) Engine Control Module (ECM) (J248) fuses OK.

• Battery voltage at least 12.5 volts.

• All electrical consumers such as, lights and rear window defroster, switched off.

• Vehicles with automatic transmission, shift selector lever into position " P" or "N".

• A/C switched off.

• Ground (GND) connections between engine/transmission/chassis OK.

• Ignition switched off.

• Engine cold.

Test procedure

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

Start diagnosis

- Perform the function test in diagnostic mode 06. Refer to => [ Diagnostic Mode 06 - Read Test Results for Specific Diagnostic Functions ] Diagnostic Mode 06 - Read Test Results For Specific Diagnostic Functions.

If the specified values were not obtained:

- Check the Diesel Direct Fuel Injection (DFI) Engine Control Module (ECM) (J248) electrical harness connector for damage, corrosion, loose or broken terminals.





If no malfunction is detected with the Diesel Direct Fuel Injection (DFI) Engine Control Module (ECM) (J248) electrical harness connector:

- Replace the Diesel Direct Fuel Injection (DFI) Engine Control Module (ECM) (J248). Refer to => [ Engine Control Module, Replacing ] Engine Control Module, Replacing.

- 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.

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 ] Readiness Code.

End of diagnosis