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

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

• The ECM detected an intermittent loss of signal or a complete loss of signal from the primary speed/timing sensor for 2 seconds.

• The engine has been running for more than three seconds.

System Response:

If equipped, the warning light will come on and the diagnostic code will be logged.

The ECM will use the signal from the secondary speed/timing sensor.

The engine will be derated. If the signal from the secondary speed/timing sensor is also lost, the engine will shut down.

This diagnostic code will detect a loss of signal from the primary speed/timing sensor.

Test Step 1. Perform the following diagnostic procedure: Engine Speed/Timing Sensor Circuit - Test

Results:

• OK - STOP