MOTOR GP-GEAR 4425647 - Caterpillar

The Engine Control Module (ECM) detects the following conditions:
The primary engine speed/timing signal was lost and then returned within one second.
The engine has been running for more than three seconds.
The engine speed did not pass through the 350 to 500 rpm range.
Battery voltage is greater than 9 VDC prior to the short or open circuit condition.System Response:The ECM will use the secondary speed/timing sensor. "DIAG" will be displayed next to the status for "Engine Speed" on Caterpillar Electronic Technician (ET).Possible Performance Effect:There should not be a noticeable change in engine response unless the signal for the secondary speed/timing sensor is also lost. This loss will shut down the engine.Troubleshooting:Test Step 1. Perform the following diagnostic procedure: "Engine Speed/Timing Sensor Circuit - Test"Results:
OK - STOP