ISB/ISBe Series Engines – 019-019   Engine Coolant Temperature Sensor

Warm Engine

Connect an electronic service tool to the vehicle’s datalink.

Turn the keyswitch to the ON position.

Monitor the coolant temperature with the electronic service tool.

Compare the coolant temperature value with the water temperature gauge in the vehicle’s dash.

If the coolant temperature on the electronic service tool is excessively higher than the water temperature or does

not increase with the water temperature, then refer to the appropriate fault code troubleshooting tree in Section TF.

Cold Engine

Remove the coolant temperature sensor.

Connect the coolant temperature sensor to the engine harness.

Connect an electronic service tool to the vehicle’s datalink.

Turn the keyswitch to the ON position.

Monitor the coolant temperature with the electronic service tool.

If the coolant temperature does

not change to the present ambient air temperature, then refer to the appropriate fault code troubleshooting tree in

Section TF.

WARNING  Do not remove the pressure cap from a hot engine. Wait until the coolant temperature is below 50°C [120°F] before removing the coolant system pressure cap. Heated coolant spray can cause personal injury.

Drain the cooling system. Refer to Procedure

008-018 in the Troubleshooting and Repair Manual, ISB (4 cylinder) and ISB

^e (4 and 6 cylinder) Series Engines, Bulletin

4021271.

Lift up on the locking tab, and pull the electrical connectors apart.

Remove the sensor.

Inspect the engine harness connector and the coolant temperature sensor for the following:

1. Cracked or broken connector shell
2. Missing or damaged connector seals
3. Dirt, debris, or moisture in or on the connector pins
4. Corroded, bent, broken, pushed back, or expanded pins.

Inspect the coolant temperature sensor for the following:

1. Damaged seal
2. Nicks or cuts in or on the seal
3. Dirt or debris on the sensor tip.

Make sure the new sensor has an o-ring installed.

Lubricate the o-ring with clean engine oil.

Install the new sensor into the engine. Tighten the sensor.

Push the connectors together until they lock.

Fill the cooling system, and operate the engine to check for leaks.

Refer to Procedure

008-018
in the Troubleshooting and Repair Manual, ISB (4 cylinder) and ISB

^e
(4 and 6 cylinder) Series Engine, Bulletin

4021271.