Charge Air Pressure Sensor/Intake Air Temperature Sensor, Checking
Charge Air Pressure Sensor/Intake Air Temperature Sensor, Checking
Observe all safety precautions: => [ Safety Precautions ] Generic Scan Tool
View clean working conditions: => [ Clean Working Conditions ] Clean Working Conditions
Use only gold-plated terminals when servicing any component with gold-plated electrical harness connector terminals.
For wiring diagrams, component locations, and connector views, Refer to the applicable wiring diagram.
Special tools, testers and auxiliary items required
• Multimeter
• Wiring diagram
Test requirements
• The Motronic Engine Control Module (ECM) (J623) fuses OK.
• Battery voltage at least 12.5 volts.
• All electrical consumers such as, lights and rear window defroster, switched off.
• On vehicles with automatic transmission, selector lever in position "P" or "N".
• A/C switched off.
• Ground (GND) connections between engine/transmission/chassis OK.
• Ignition switched off.
Test procedure
- Perform a preliminary check to verify the customers complaint. Refer to => [ Preliminary Check ] Preliminary Check
Start diagnosis
- Remove the engine cover with air filter. Refer to appropriate service information.
Test sequence
- Disconnect the Charge Air Pressure Sensor/Intake Air Temperature Sensor (G31/G72) electrical harness connector - 1 -.
On the right side, on the compressor with the charge air cooler. Note: The intake air temperature sensor 2 -G430- / charge air pressure sensor 2 -G447- are arranged as mirror images of each other.
- Start engine and let it run at idle.
- Using a multimeter, check the Charge Air Pressure Sensor/Intake Air Temperature Sensor (G31/G72) electrical harness connector terminals 1 to 2 for voltage.
Specified value: min. 4.5 V
- Switch the ignition off.
If the specification was obtained:
- Replace the Charge Air Pressure Sensor/Intake Air Temperature Sensor (G31/G72).
If the specification was not obtained:
Checking wiring
If the manufacturers test box is being used, perform the following step.
- Install the test box.
If the manufacturers test box is not being used, perform the following step.
- Remove the Motronic Engine Control Module (ECM) (J623). Refer to appropriate service information.
- Using a multimeter, check the Charge Air Pressure Sensor/Intake Air Temperature Sensor (G31/G72) electrical harness connector terminals to the Motronic Engine Control Module (ECM) (J623)electrical harness connector T94 terminals for an open circuit according to wiring diagram.
Specified value: 1.5 ohms max.
If the specification was not obtained:
- Check the wiring for a short circuit to each other, Battery (+), and Ground (GND).
- If necessary, repair the faulty wiring connection.
- Check the electrical harness connector for damage, corrosion, loose or broken terminals.
If no malfunction is detected in the wiring and if the voltage supply was OK:
- Replace the Charge Air Pressure Sensor/Intake Air Temperature Sensor (G31/G72).
If no malfunction is detected in the wiring and if the voltage supply was not OK:
- Replace the Motronic Engine Control Module (ECM) (J623). Refer to appropriate service information.
- Install the engine cover with air filter. Refer to appropriate service 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.