Testing if display approx. 140° C:
-- Disconnect the MAF / IAT sensor -G70 / G42- electrical harness connector.
-- Check the value indicated on the scan tool display.
If indication jumps to approx. -40° C or -46° C:
-- Switch ignition off.
-- Replace the MAF / IAT sensor -G70 / G42- Refer to the Repair information.
If the indication remains at approx. 140° C
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 the Repair information.
-- Disconnect the ECM harness.
-- Using a multimeter, check the MAF / IAT sensor -G70 / G42- electrical harness connector terminal 5 to engine ground.
Specified value: OL or no continuity.
If the specified value was Not obtained:
-- Check the wiring for a short circuit to ground.
-- 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 the sensor resistance was OK:
-- Replace the Motronic Engine Control Module (ECM) -J623-. Refer to the Repair information.
Final procedures
After the repair work, the following work steps must be performed in the following sequence:
- Check the DTC memory. Refer to DIAGNOSTIC MODE 03 - READ DTC MEMORY .
- If necessary, erase the DTC memory. Refer to DIAGNOSTIC MODE 04 - ERASE DTC MEMORY .
- If the DTC memory was erased, generate readiness code. Refer to READINESS CODE .