C4.4 and C6.6 Industrial Engines and Engines for Caterpillar Built Machines Caterpillar

The Electronic Control Module (ECM) detects the following conditions:

• The signal voltage from the engine coolant temperature sensor is less than 0.2 Volts DC for more than eight seconds.

• The ECM has been powered for at least two seconds.

• Diagnostic code 0168-01 is not active.

System Response:

The ECM will default to 90 °C (194 °F) for engine coolant temperature. "Voltage Below Normal" will be displayed next to the status for "Engine Coolant Temperature" on the electronic service tool.

If equipped, the warning light will come on. An active diagnostic code will be generated after 8 seconds. The diagnostic code will be logged if the engine has been operating for more than 7 minutes.

• Poor stability

• Poor cold running

• White smoke

The diagnostic code will detect an excessively low voltage from the engine coolant temperature sensor.

Test Step 1. Perform the following diagnostic procedure: Engine Temperature Sensor Open or Short Circuit - Test

Results:

• OK - STOP