ENGINE AR-PRIMARY 3107852 - Caterpillar

Illustration 6 g01142103
Engine speed/timing sensors (4) Bracket (5) Secondary speed/timing sensor (6) Mounting plate (7) O-ring seals (8) Bracket (9) Primary speed/timing sensor
Remove the suspect engine speed/timing sensor from the engine.
Ensure that O-ring seals (4) are installed on each sensor and on the mounting plate. Ensure that the O-ring seals are free of damage.Expected Result:All of the O-ring seals are properly installed and free of damage. The bracket is free of damage.Results:
OK - The O-ring seals are properly installed. The bracket is free of damage.Repair: Perform the following procedure in order to properly install a sensor assembly:
Lubricate the O-ring seals with oil.
Fully seat each sensor into the housing.
Tighten the bracket bolt.
Connect the connector and verify that the latch tab of the connector is latched on both sides.
Ensure that the harness is properly secured, and ensure that the harness is attached to the harness clip. Proceed to Test Step 3.
Not OK - The sensor assembly is damaged or broken.Repair: Replace the sensor assembly.Note: Do not switch the positions of the sensors. The sensors are not interchangeable. A timing calibration is not required when the sensors are replaced.
Lubricate each O-ring with oil.
Fully seat the sensor into the housing.
Tighten the bracket bolt.
Connect the connector and verify that the latch tab of the connector is latched on both sides.
Ensure that the harness is properly secured, and ensure that the harness is attached to the harness clip.Verify that the problem is resolved.STOPTest Step 3. Check for Active Diagnostic Codes
Connect Caterpillar Electronic Technician (ET) to the service tool connector.
Turn the keyswitch to the ON position.
Start the engine and run the engine. The problem may occur when the engine is at any operating temperature. However, the problem is more likely to occur when the engine is at the normal operating temperature.
If the engine will not start, monitor the engine speed on Cat ET while the engine is being cranked. Cat ET may need to be powered from another battery while the engine is being cranked. This is done so that Cat ET will not reset.Note: Upon initial cranking, the status for engine speed may indicate that the engine speed signal is abnormal. This message should be replaced with an engine speed once the ECM is able to calculate a speed from the signal.
Check for one of the following logged diagnostic codes or active diagnostic codes:
190-08
342-08 Expected Result:One of the above codes are active or logged.Results:
Active Code - There is an active code for an engine speed/timing sensor. Proceed to Test Step 4.
Logged Code - There is a logged code for an engine speed/timing sensor. Proceed to Test Step 6.
No engine rpm - Engine speed is not indicated on Cat ET. Proceed to Test Step 4.Test Step 4. Measure the Sensor's Resistance through the Engine Harness
Turn the keyswitch to the OFF position.
Disconnect the P2 connector.
Perform the following procedure in order to measure the resistance of the primary engine speed/timing sensor:
Measure the resistance from P2-35 (Primary engine speed/timing +) to P2-25 (Primary engine speed/timing −).Resistance ... 110 to