DTC P0118 - ENGINE COOLANT TEMPERATURE (ECT) SENSOR Honda Odyssey I

1. Turn ignition on. Using scan tool, check ECT. If -4°F (-20°C) or less is not indicated, problem is intermittent. System is okay at this time. Check for poor connections or loose wires in ECT circuits between ECT sensor connector, and PCM connector. See «WIRING DIAGRAMS»(ref-16063-S09829279722001010800000) section.
2. If -4°F (-20°C) or less is indicated, disconnect ECT sensor connector. Install jumper wire between ECT harness connector terminals. Using scan tool, check ECT. If -4°F (-20°C) or less is not indicated, replace ECT sensor. If -4°F (-20°C) or less is indicated, turn ignition off.
3. Install jumper wire between PCM connector terminals D2 and D11. On all models, turn ignition on. Using scan tool, check ECT. If -4°F (-20°C) or less is not indicated, repair open in ECT and SG2 circuit between ECT sensor and PCM connector terminals D2 and D11. See «WIRING DIAGRAMS»(ref-16063-S09829279722001010800000) section. If -4°F (-20°C) or less is indicated, substitute a known-good PCM and recheck. If symptom or indication goes away, replace original PCM.

Scheme 16

1. Turn ignition on. Using scan tool, check TP sensor. If reading is approximately 10% with throttle fully closed and 90% with throttle fully opened, problem is intermittent. System is okay at this time. Check for poor connections or loose wires in TP circuits between TP sensor connector and PCM connector. See «WIRING DIAGRAMS»(ref-16063-S09829279722001010800000) section.
2. If reading is not approximately 10% with throttle fully closed and 90% with throttle fully opened, turn ignition off. Disconnect TP sensor connector. Turn ignition on. Measure voltage between TP sensor harness connector terminals No. 1 (SG2) and 3 (VCC2). (Scheme 16) If reading is approximately 5 volts, go to step 4).
3. If reading is not approximately 5 volts, measure voltage between PCM connector terminals D10 and D11. see scheme 4 If reading is approximately 5 volts, repair open in SG2 circuit between PCM connector TP sensor terminal. See «WIRING DIAGRAMS»(ref-16063-S09829279722001010800000) section. If reading is not approximately 5 volts, substitute a known-good PCM and recheck. If symptom or indication goes away, replace original PCM.
4. Turn ignition off. Measure resistance between TP sensor terminals No. 1 (SG2) and No. 2 (TP) with throttle closed. (Scheme 16) If resistance is not approximately 500 ohms, replace TP sensor. If resistance is approximately 500 ohms), measure resistance between TP sensor terminals No. 2 (TP) and 3 (VCC2) with throttle fully closed.
5. If resistance is not approximately 4500 ohms, replace TP sensor. If resistance is approximately 4500 ohms, reconnect TP sensor and go to next step.
6. Turn ignition on. Measure voltage between PCM connector terminals D1 and D11. see scheme 4 If voltage is approximately.5 volt with throttle fully closed and 4.5 volts with throttle fully open, substitute a known-good PCM and recheck. If symptom or indication goes away, replace original PCM.
7. If voltage is not approximately.5 volt with throttle fully closed and 4.5 volts with throttle fully open, repair short in circuit between PCM connector terminal D1 and TP sensor. See WIRING DIAGRAMS section.
8. Turn ignition off. Disconnect TCM connectors. Turn ignition on. Measure voltage between PCM connector terminals D1 and D11. If voltage is approximately.5 volt with throttle fully closed and 4.5 volts with throttle fully open, replace Transmission Control Module (TCM).
9. If voltage is not approximately.5 volt with throttle fully closed and 4.5 volts with throttle fully open, repair short in circuit between PCM connector terminal D1, TCM connector, and TP sensor connector. See «WIRING DIAGRAMS»(ref-16063-S09829279722001010800000) section.