DTC P0117-P0118: Engine Coolant Temperature (ECT) Circuit
NOTE:
T-5 ECT sensor is under upper engine cover and has Yellow/White and Black wires running to it.
- Disconnect T-5 ECT sensor harness connector. Connect SST 86 11 857 test light (or equivalent) between positive battery terminal and ECT sensor harness connector terminal No. 2 (Black wire). See Fig 1 . If test light illuminates, go to next step. If test light does not illuminate, check for faulty circuit between ECT sensor harness connector terminal No. 2 and splice connector J31 (Black wire) located about 2" from ECM harness connector. ECM is next to glove box on right side. See appropriate wiring diagram in WIRING DIAGRAMS article. Repair as necessary and go to step 4 .
- Turn ignition off. Connect TECH 2 scan tool to DLC. Turn ignition on. Contact TRIONIC 5 OBD II. Select READING: COOLANT TEMPERATURE. If scan tool display is around -40°F (-40°C), go to next step. If readings are not as specified, check for faulty circuit between ECT sensor harness connector terminal No. 1 and ECM harness connector terminal No. 68 (Yellow/White wire). See Figure for ECM terminal identification. Repair as necessary and go to step 4 .
- Connect a jumper wire between ECT sensor harness connector terminals No. 1 and 2. Reading on scan tool should now be 257-266°F (125-130°C). If reading is as specified, replace ECT sensor. See ENGINE COOLANT TEMPERATURE (ECT) SENSOR under ENGINE SENSORS & SWITCHES in REMOVAL, OVERHAUL & INSTALLATION article. If reading is not as specified, check for faulty circuit between ECT sensor harness connector terminal No. 1 and ECM harness connector terminal No. 68 (Yellow/White wire). Repair as necessary. Go to next step.
- Use scan tool to clear DTCs. Drive vehicle for 5 minutes under varying loads and engine RPM. Recheck for any stored DTCs. If DTC P0117-P0118 is present, substitute known good ECM and retest system. See ENGINE CONTROL MODULE (ECM) under COMPUTERIZED ENGINE CONTROLS in REMOVAL, OVERHAUL & INSTALLATION article.