The Engine Speed/Timing Sensors provide engine information to the Electronic Control Module (ECM). The sensor generates a pulse signal. A loss of the signal causes the ECM to stop sending power to the fuel injectors.
If the Primary Engine Speed/Timing Sensor fails, the ECM will use the Secondary Engine Speed/Timing Sensor until electrical power is removed from the ECM. To prevent any unnecessary down time, the primary sensor should be repaired or replaced at the earliest possible convenience.
Test Step 1. Check for an Engine Diagnostic Code.
- Connect the Caterpillar Electronic Technician (ET).
- Start the engine.
- Operate the engine until normal operating temperatures are obtained.
Expected Result:
There should be one active Diagnostic Code 261-13.
Results:
- OK - There is one active Diagnostic Code 261-13. Proceed to test step 2.
- Not OK - There are other active Diagnostic Codes.
Repair: Repair any active Diagnostic Codes.
Stop.
Test Step 2. Calibrate the Fuel Injection Timing.
- Select the Monitor/Calibrate Timing screen on the Cat ET.
The end of the Timing Error bar should always be within the tolerance lines. If the Timing Error bar is NOT within the two sets of vertical timing error tolerance lines, the timing calibration is incorrectly set.
- To calibrate the timing to the correct setting, press the space key on the Cat ET. Wait until the Cat ET indicates that the timing is calibrated.
Note: Engine rpm will be set to 800 rpm. Verify that the timing has been calibrated. Observe the Timing Error bar on the Cat ET.
Note: If the Cat ET reads "COULD NOT CALIBRATE" the timing has not been set.
Expected Result:
The Timing Calibration procedure was successful.
Results:
- OK - The Timing Calibration procedure was completed successfully. Stop.
- Not OK - The Timing could not be calibrated.
Repair: Check for excessive backlash in the gear train.
Stop.