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) (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 (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 specified value was obtained:
- Condition is not present at this time. Check connections for loose or damaged terminals and check harness for an intermittant short.
If the specified value was Not obtained:
Test sequence
- 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 specified value was 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) (J220). 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 terminal 4 to the Motronic Engine Control Module (ECM) (J220) electrical harness connector T121 terminal 101 for resistance.
- Check the wiring for an open circuit, high resistance, short circuit to each other, Battery (+), or 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 the specified value of 4.5 V was Not obtained:
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) (J220). 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 resistance.
Specified value: 1.5 ohms 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 (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 Not OK:
- Replace the Motronic Engine Control Module (ECM) (J220). Refer to => [ Motronic Engine Control Module, Replacing ] Motronic Engine Control Module, Replacing.
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.