5031024 JOHNSON KEY

Illustration 1 g00782186
Sensor locations (typical example)
Illustration 2 g00889942
Schematic
Test Step 1. Verify All Active Diagnostic Codes
Connect the Caterpillar Electronic Technician (ET) to the service tool connector.
Place the engine control in the ON mode. Wait at least 15 seconds for activation of the diagnostic codes.
Verify whether any of the following diagnostic codes are active:
110-03
110-04
172-03
172-04
175-03
175-04 Expected Result:One or more of the preceding diagnostic codes are active.Results:
OK - One or more of the preceding diagnostic codes are active. Proceed to Test Step 2.
Not OK - One or more of the preceding diagnostic codes are not active.Repair: If the preceding codes are logged but not active and the engine is not running properly, refer to Troubleshooting, "Troubleshooting without a Diagnostic Code". If the engine is running properly at this time, an intermittent condition may be causing the logged codes. Refer to Troubleshooting, "Electrical Connections - Inspect". STOPTest Step 2. Inspect Electrical Connectors And Wiring
Illustration 3 g00765339
P2 ECM connector
Thoroughly inspect ECM engine harness connector J2/P2 and the suspect sensor connector. Refer to Troubleshooting, "Electrical Connectors - Inspect" for details.
Perform a 45 N (10 lb) pull test on each of the wires in the sensor connector and the ECM connector that are associated with the active diagnostic code.
Verify that the latch tab of the connector is properly latched and that the latch tab of the connector has returned to the fully latching position.
Check the ECM connector (allen head screw) for the proper torque of 6.0 N m (55 lb in).
Check the harness and wiring for abrasions and for pinch points from the sensor to the ECM. Expected Result:All connectors, pins, and sockets are completely coupled and/or inserted. The harness and wiring are free of corrosion, of abrasion, and of pinch points.Results:
OK - The connectors and the wiring is good. Proceed to Test Step 3.
Not OK - There is a problem with the connectors and the wiring.Repair: Repair the connectors or wiring and/or replace the connectors or wiring. Ensure that all of the seals are properly in place and ensure that the connectors are completely coupled.Verify that the repair eliminates the problem.STOPTest Step 3. Verify That The Diagnostic Code Is Still Active
Place the engine control in the ON mode. Wait at least 15 seconds for activation of the diagnostic codes.
Access the "Active Diagnostic Code" screen of the electronic service tool. Check for active diagnostic codes.
Determine if the problem is related to an open circuit diagnostic code or a short circuit diagnostic code. Expected Result:A short circuit diagnostic code or an open circuit diagnostic code is active.Results:
Short Circuit - A short circuit diagnostic code is active at this time. Proceed to Test Step 4.
Open Circuit - An open circuit diagnostic code is active at this time. Proceed to Test Step 5.Test Step 4. Disconnect The Sensor In Order To Create An Open Circuit
Place the engine control in the OFF/RESET mode.
Disconnect the sensor connector of the sensor with the short circuit diagnostic code.
Place the engine control in the ON mode. Wait at least 15 seconds for activation of the diagnostic codes.
Access the "Active Diagnostic Code" screen of the electronic service tool. Check for an active open circuit diagnostic code. Expected Result:An open circuit diagnostic code for the disconnected sensor is now active.Results:
OK - A short circuit diagnostic code was active before disconnecting the sensor. An open circuit diagnostic code became active after disconnecting the sensor. Proceed to Test Step 6.
Not OK - There is a short circuit between the sensor harness connector and the ECM. Leave the sensor disconnected. Proceed to Test Step 7.Test Step 5. Create A Short Circuit Between The Signal And The Common Terminals At The Sensor Connector
Place the engine control in the ON mode.
Fabricate a jumper wire 150 mm (6 inch) long. Crimp a Deutsch terminal to both ends of the wire.
Monitor the "Active Diagnostic Code" screen before installing the jumper wire and after installing the jumper wire.
Install the jumper on the engine harness connector. Install one end of the jumper at the sensor signal (terminal 1). Install the other end of the jumper at the common connection for the engine temperature sensor (terminal 2). Wait at least 15 seconds for activation of the short circuit diagnostic code. Expected Result:A short circuit diagnostic code is active when the jumper is installed. An open circuit diagnostic code is active when the jumper is removed.Results:
OK - The engine harness and the ECM are OK.Repair: Perform the following repair:
Temporarily connect the suspect sensor.
If the diagnostic code remains active, replace the sensor.
Verify that the repair eliminates the problem.
Clear all logged diagnostic codes. STOP
Not OK - The open circuit diagnostic code remains active with the jumper in place. The most probable location for the open is in the sensor common or the sensor signal wire in the engine harness between the ECM and the sensor. Remove the jumper. Proceed to Test Step 7.Test Step 6. Determine If The Short Circuit Is In The Connector Or In The Sensor
Thoroughly inspect the connector for moisture.
Inspect the seals and reconnect the sensor.
If the short circuit diagnostic code reappears, the sensor is the problem.
Temporarily connect a new sensor to the harness, but do not install the new sensor in the engine.
Check for a short circuit diagnostic code while the new sensor is connected to the harness. Expected Result:The short circuit diagnostic code is not present when a new sensor is connected.Results:
OK - Verify that the repair eliminates the problem. Clear the logged diagnostic codes.STOP
Not OK - Repair: Repair the engine harness connector.STOPTest Step 7. Check The Operation Of The ECM By Creating Open And Short Circuits At The ECM Connector
Illustration 4 g00765339
P2 ECM connector
Place the engine control in the OFF/RESET mode.
Disconnect the connector for the