DaimlerChrysler Jeep Grand Cherokee 2002 Service Manual page 44

DRIVEABILITY - DIESEL
P0115-ENGINE COOLANT TEMP SENSOR CIRCUIT SIGNAL VOLTAGE
TOO HIGH —
Continued
TEST
3 Turn the ignition off.
Disconnect the ECT Sensor harness connector.
Connect a jumper wire between the ECT Sensor harness connector cavities.
Turn the ignition on.
With the DRB, read the ECT Sensor voltage.
Is the voltage below 1.0 volt?
Yes → Replace the ECT Sensor in accordance with the Service Informa-
→ Go To 4
No
4 Turn the ignition off.
Disconnect the ECT Sensor harness connector.
Disconnect the ECM harness connectors.
Measure the resistance of the ECT Sensor Ground circuit.
Is the resistance below 10.0 ohms?
Yes → Go To 5
→ Repair the ECT Sensor Ground circuit for an open.
No
5 Turn the ignition off.
Disconnect the ECM harness connectors.
Disconnect the ECT Sensor harness connector.
Measure the resistance of the ECT Sensor Signal circuit.
Is the resistance below 10.0 ohms?
Yes → Go To 6
→ Repair the ECT Sensor Signal circuit for an open.
No
6 If there are no possible causes remaining, view repair.
Repair
ACTION
tion.
Perform ROAD TEST VERIFICATION - VER-2.
Perform ROAD TEST VERIFICATION - VER-2.
Perform ROAD TEST VERIFICATION - VER-2.
Replace and program the Engine Control Module in accordance
with the Service Information.
Perform ROAD TEST VERIFICATION - VER-2.
36
APPLICABILITY
All
All
All
All