DETECTED CONDITION | POSSIBLE CAUSE |
Output voltage is out of the specified range. 0.1 V ≤ Sensor voltage ≤ 4.6 V | • ECT sensor circuit open or short. • ECT sensor malfunction. • ECM malfunction. |
Inspection
Step 1
1) Turn the ignition switch OFF.
2) Check the ECT sensor coupler for loose or poor contacts. If OK, then measure the ECT sensor voltage at the wire side coupler.
3) Disconnect the coupler and turn the ignition switch ON.
4) Measure the voltage between B/BI wire terminal (1) and ground.
5) If OK, then measure the voltage between B/Bl wire terminal (1) and B/Br wire terminal (2).
- ETC sensor voltage: 4.5 - 5.5 V
- ((+) B/BI - (-) Ground)
- ((+) B/BI - (-) B/Br)
- 09900-25008: Multi circuit tester set
- Tester knob indication: Voltage (⎓)
Is the voltage OK?
YES | Go to Step 2 |
NO | • Loose or poor contacts on the ECM coupler. • Open or short circuit in the B/BI wire or B/Br wire. |
Step 2
1) Turn the ignition switch OFF.
2) Measure the ECT sensor resistance. (Refer to page 6-10 for details.)
- ECT sensor resistance: Approx. 2.45 kΩ at 20°C (68°F) (Terminal - Terminal)
- 09900-25008: Multi circuit tester set
- Tester knob indication: Resistance (Ω)
Is the resistance OK?
YES | • B/Br or B/BI wire open or shorted to ground, or poor (34) or (36) connection. • If wire and connection are OK, intermittent trouble or faulty ECM. • Recheck each terminal and wire harness for open circuit and poor connection. |
NO | Replace the ECT sensor with a new one. |
Engine Coolant Temp | Resistance |
20°C (68°F) | Approx. 2.45 kΩ |
40°C (104°F) | Approx. 1.148 kΩ |
60°C (140°F) | Approx. 0.587 kΩ |
80°C (176°F) | Approx. 0.322 kΩ |