ROD AS 0R1427 - Caterpillar

Illustration 6 g01212995
Typical example of the speed/timing sensor (1) Supply (2) SignalTest Step 1. Inspect the Electrical Connectors and the Harness
Turn the keyswitch to the OFF position.
Illustration 7 g01325579
Typical engine ECM (1) P2 ECM connector (2) P1 ECM connector
Thoroughly inspect the P2 connector and the circuit that is associated with the suspect sensor. Refer to service Troubleshooting, "Electrical Connectors - Inspect".
Perform a 45 N (10 lb) pull test on each of the wires that are associated with the engine speed/timing sensors.
Check the torque of the allen head screws for the ECM connectors. Refer to serviceTroubleshooting, "Electrical Connectors - Inspect" for the correct torque values.
Check the harness and the wiring for abrasion and for pinch points from each sensor back to the ECM.
Check that the suspect sensor is installed correctly. Check that the suspect sensor is fully seated into the engine. Check that the sensor is securely latched.Expected Result:All of the connectors, pins and sockets are completely coupled and/or inserted and the harness and wiring are free of corrosion, of abrasion and of pinch points.Results:
OK - The connectors and/or wiring are OK. Proceed to Test Step 2.
Not OK - The connectors and/or wiring are Not OK.Repair: Repair the faulty connectors or the harness and/or replace the faulty connectors or the harness. Ensure that all of the seals are correctly in place and ensure that the connectors are correctly coupled.If a sensor must be replaced or the sensor must be reinstalled, complete all of the following tasks:
Lubricate the O-ring with clean engine lubricating oil.
Ensure that the plug for the sensor has a seal inside the connector body. If a seal is damaged or missing, replace the seal.
Ensure that the sensor is fully seated into the engine before tightening the bracket bolt.
Ensure that the connector is latched.
Ensure that the harness is correctly secured, and ensure that the harness is attached to the harness clip.Verify that the repair eliminates the problem.If applicable, use Caterpillar Electronic Technician (ET) to perform a wiggle test.STOPTest Step 2. Check for Active Diagnostic Codes and Recently Logged Diagnostic Codes
Turn the keyswitch to the OFF position.
Connect Cat ET to the diagnostic connector.
Turn the keyswitch to the ON position.
With the engine diagnostics disabled, monitor the "Status Screen" on Cat ET to determine if there is a valid input from both of the speed/timing sensors.Note: The diagnostics for the speed/timing sensors may be erratic during engine cranking.
If the engine will start, run the engine.
Use Cat ET in order to monitor active diagnostic codes or recently logged diagnostic codes. Expected Result:One or more of the following diagnostic codes are active or recently logged:
190-8 Engine Speed Sensor : Abnormal Frequency, Pulse Width, or Period
342-8 Secondary Engine Speed Sensor : Abnormal Frequency, Pulse Width, or PeriodResults:
OK - One or more of the diagnostic codes are active or recently logged. Proceed to Test Step 3.
Not OK - No diagnostic codes are active.Repair: If the engine is running properly at this time, there may be an intermittent problem in a harness that is causing the codes to