CHECKING WIRING
Remove the Engine Control Module (ECM) -J623-. Refer to the Repair Information.
Using a multimeter, check the Engine Coolant Temperature (ECT) Sensor -G62 or 83- electrical harness connector terminals to the Engine Control Module (ECM) -J623- electrical harness connector T60 terminals for an open circuit or a short to voltage, refer to the chart below.
| Engine Coolant Temperature (ECT) Sensor - G62- electrical harness connector terminals | Engine Control Module (ECM) -J623- electrical connector T60 terminals |
|---|---|
| 1 | 57 |
| 2 | 14 |
OR
| Engine Coolant Temperature (ECT) Sensor - G83- electrical harness connector terminals | Engine Control Module (ECM) -J623- electrical connector T94 terminals |
|---|---|
| 1 | 36 |
| 2 | 12 |
Specified values: 1.5 ohms Max. and 0 volts with key on and ECM disconnected.
If the specified value was Not obtained
Check the wiring for an open or short circuit to Battery (+).
Check the electrical harness connector for damage, corrosion, loose or broken terminals.
If necessary, repair the faulty wiring connection.
If the specified value was obtained
Using a multimeter, check terminal 2 of the ECT sensor to engine ground.
Specified value: 1.5 ohms Max
If the specified value was Not obtained
Check the wiring for an open circuit or high resistance.
Check the electrical harness connector for damage, corrosion, loose or broken terminals.
If necessary, repair the faulty wiring connection.
If the specified value was obtained
Replace the Engine Control Module (ECM) -J623-. Refer to the Repair Information.
Remove the Engine Control Module (ECM) -J623- and disconnect the ECM connectors. Refer to the Repair Information.
Disconnect the ECT harness connector at the sensor.
Using a multimeter, check the signal circuit of the Engine Coolant Temperature (ECT) Sensor -G62 or 83- electrical harness connector terminal 1 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.
Check the electrical harness connector for damage, corrosion, loose or broken terminals.
If necessary, repair the faulty wiring connection.
If the specified value was obtained
Replace the Engine Control Module (ECM) -J623-. Refer to the Repair Information.
Remove the Engine Control Module (ECM) -J623-. Refer to the Repair Information.
Disconnect the ECM harness.
Using a multimeter, check the IAT sensor -G42- electrical harness connector terminal 1 to the Engine Control Module (ECM) -J623- electrical harness connector T60 terminal 42 for an open circuit or a short to voltage, refer to the wiring diagram.
Specified values: Circuit continuity; 1.5 ohms max; Circuit voltage = 0 volts when disconnected from ECM (with ignition on).
If the specified value was Not obtained
Check the wiring for an open, high resistance or short circuit to Battery (+)
Check the electrical harness connector for damage, corrosion, loose or broken terminals.
If necessary, repair the faulty wiring connection.
If the specified value was obtained
Using a multimeter, check terminal 2 of the IAT sensor to engine ground.
Specified value: 1.5 ohms Max
If the specified value was Not obtained
Check the wiring between terminal 2 of the IAT and T60/14 of the ECM connector for an open circuit or high resistance.
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 ground circuit
Replace the Engine Control Module (ECM) -J623-. Refer to the Repair Information.