Resistance Inspection

NOTE: Perform the following test only when directed.

ECT Sensor Resistance Inspection

1. Drain the engine coolant. (Refer to COOLING SYSTEM SERVICE WARNINGS.) (Refer to ENGINE COOLANT REPLACEMENT.)
2. Remove the ECT sensor.




3. Place the ECT sensor in water with a thermometer, and heat the water gradually.
4. Measure the resistance between the ECT sensor terminals A and C using an ohmmeter.




Specification

- If not as specified, replace the ECT sensor.

- If the ECT sensor is okay, but PID value or PCM terminal 38 voltage are out of specification, inspect as follows.
1. Remove the PCM.




2. Connect the SST (104 Pin Breakout Box) to the PCM as shown.
3. Tighten the connector attaching screw.

Tightening torque
7.9 - 10.7 Nm (80 - 110 kg.cm, 69.5 - 95.4 in.lb)

4. Inspect for an open or short circuit in the following wiring harnesses by probing the applicable sensor and SST (104 Pin Breakout Box) terminals with ohmmeter leads.
- If there is an open or short circuit, repair or replace wiring harnesses.
- If there is no open or short circuit, replace the ECT sensor.




Open circuit
- ECT signal circuit (ECT sensor connector terminal C and PCM connector terminal 38 through common connector)
- Ground circuit (ECT sensor connector terminal A and PCM connector terminal 91)

Short circuit
- ECT signal circuit (ECT sensor connector terminal C and PCM connector terminal 38 to Ground)
- Ground circuit (ECT sensor connector terminal A and PCM connector terminal 91 to Ground)

5. Install the ECT sensor.