Testing if display approx. 140° C
-- Disconnect the Mass Air Flow (MAF) Sensor -G70- /Intake Air Temperature (IAT) Sensor -G42- electrical harness connector.
If indication jumps to approx. -40 °C or -46 °C:
-- End diagnosis and switch ignition off.
-- Replace the Mass Air Flow (MAF) Sensor -G70- /Intake Air Temperature (IAT) Sensor -G42-. Refer to appropriate service information.
If the indication remains at approx. 140 °C:
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 Engine Control Module (ECM) -J220-. Refer to appropriate service information.
-- Using a Multimeter --, check the Mass Air Flow (MAF) Sensor -G70- /Intake Air Temperature (IAT) Sensor -G42- electrical harness connector terminals to the Engine Control Module (ECM) -J220- electrical harness connector T121 terminals for resistance.
| Mass Air Flow (MAF) Sensor -G70- /Intake Air Temperature (IAT) Sensor -G42- electrical harness connector terminals | Engine Control Module (ECM) -J220- electrical harness connector T121 terminals or test box socket |
|---|---|
| 1 | 26 |
| 3 | 27 |
Specified value: 1.5 Ω Max.
If the specification was not obtained:
-- Check the wiring for an open circuit, a short circuit to Battery (+), or an open circuit.
-- 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:
-- Erase the DTC memory. Refer to DIAGNOSTIC MODE 04 - ERASE DTC MEMORY .
-- Perform a road test to verify repair.
If the DTC does not return:
Generate readiness code. Refer to READINESS CODE .
If the DTC does return and no malfunction is detected in the wiring and the voltage supply was not OK:
-- Replace the Engine Control Module (ECM) -J220-. Refer to appropriate service information.
Final procedures
After repair work, the following work steps must be performed in the mentioned sequence:
- Check the DTC memory. DIAGNOSTIC MODE 03 - READ DTC MEMORY .
- If necessary, erase the DTC memory. DIAGNOSTIC MODE 04 - ERASE DTC MEMORY .
- If the DTC memory was erased, generate readiness code. READINESS CODE .