The Electronic Control Module (ECM) detects all of the following conditions:
- The engine speed is greater than 0 rpm.
- The pattern for the timing ring is incorrect for five seconds.
The ECM will log a diagnostic code, and the ECM will have an active diagnostic code if the ECM detects all of the following conditions:
- The engine speed is greater than 0 rpm.
- The pattern for the timing ring is incorrect for five seconds.
- The pattern for the timing ring is correct again for five seconds.
System Response:
The ECM will log the diagnostic code. The diagnostic code may be viewed on a display module or on the Caterpillar Electronic Technician (ET). If a valid signal is not received from the primary engine speed/timing sensor, the ECM will default to the secondary engine speed/timing sensor.
Possible Performance Effect:
- Engine misfires
- Engine shutdown
Note: The engine will shut down only if both the primary engine speed/timing sensor and the secondary engine speed/timing sensor are abnormal.
Troubleshooting:
Test Step 1. Perform the following diagnostic procedure: "Engine Speed/Timing Sensor Circuit - Test"
Results:
- OK - STOP