0321677 JOHNSON ROD,Reverse lock release

Illustration 1 g01788353
Schematic for engine temperature sensors
Illustration 2 g01788354
Terminal locations at the P1 ECM connector
(P1-18) Sensor common
(P1-26) Ambient air temperature
Illustration 3 g01150436
Terminal locations at the P2 ECM connector
(P2-18) Sensor common
(P2-32) Engine coolant temperature
(P2-35) Intake manifold air temperature Test Step 1. Check for Active Diagnostic Codes
Connect Caterpillar Electronic Technician (ET) to the service tool connector.
Turn the keyswitch to the ON position. Wait at least 30 seconds for activation of the diagnostic codes.
Monitor the "Active Diagnostic Codes" screen on Cat ET. Expected Result:There is an active diagnostic code for one or more of the temperature sensors.Results:
OK - There is an active diagnostic code for one or more of the temperature sensors. Proceed to Test Step 2.
Not OK - There are no active diagnostic codes for the temperature sensors.Repair: If there are logged diagnostic codes for one or more of the temperature sensors and the engine is not running properly, refer to the diagnostic section Troubleshooting, "Troubleshooting without a Diagnostic Code". If the engine is running properly at this time, an intermittent condition may be causing logged codes. Refer to the diagnostic functional test Troubleshooting, "Electrical Connectors - Inspect". STOPTest Step 2. Inspect the Electrical Connectors and the Wiring
Turn the keyswitch to the OFF/RESET position.
Thoroughly inspect the J2/P2 ECM connector, the suspect sensor connector, and any other connectors in the circuit. Refer to the diagnostic functional test 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.
Check the allen head screw for each ECM connectors for the proper torque. Refer to Troubleshooting, "Electrical Connectors - Inspect" for the correct torque values.
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 wiring are OK. Proceed to Test Step 3.
Not OK - There is a problem in the connectors and/or 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. Check for "Active" or "Logged" Diagnostic Codes
Turn the keyswitch to the ON position. Wait at least 15 seconds for activation of the diagnostic code.
Access the "Active Diagnostic Codes" screen on Cat ET and check for active diagnostic codes.
Determine if the problem is related to an open circuit diagnostic code 03 or a short circuit diagnostic code 04. Expected Result:No active codes are present.Results:
OK - No active codes are present.Repair: The problem seems to be resolved. There appears to be an intermittent problem in the wiring or in a connector. Carefully reinspect the connectors and wiring in order to identify the problem. Refer to the diagnostic functional test Troubleshooting, "Electrical Connectors - Inspect" for additional information.STOP
Not OK - A short circuit diagnostic code -4 is active at this time. Proceed to Test Step 4.
Not OK - An open circuit diagnostic code -3 is active at this time. Proceed to Test Step 5.Test Step 4. Create an Open Circuit at the Sensor Connector
Turn the keyswitch to the OFF/RESET position.
Disconnect the connector to the sensor with the short circuit diagnostic code -4.
Turn the keyswitch to the ON position. Wait at least 30 seconds for activation of the diagnostic codes.
Access the "Active Diagnostic Codes" screen on Cat ET and check for an active open circuit diagnostic code -3 for the suspect sensor. Expected Result:An open circuit diagnostic code -3 is now active for the disconnected sensor.Results:
OK - A short circuit diagnostic code -4 was active before disconnecting the sensor. An open circuit diagnostic code -3 became active after disconnecting the sensor.Repair: 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 -4 while the new sensor is connected. If the short circuit diagnostic code -4 is not present, permanently install a new sensor. Clear any logged diagnostic codes.Verify that the repair eliminates the problem.STOP
Not OK - The short circuit diagnostic code -4 remains present. There is probably a short circuit between the sensor harness connector and the ECM. Leave the sensor disconnected at the sensor harness connector. Proceed to Test Step 6.Test Step 5. Create a Short Circuit at the Sensor Connector
Turn the keyswitch to the OFF/RESET position.
Unplug the suspect sensor at the suspect sensor's harness connector.
Fabricate a jumper wire that is long enough to create a test circuit at the sensor connector. Crimp connector sockets to each end of the jumper wire.
Install the jumper wire across the terminals at the harness connector for the suspect sensor.
Turn the keyswitch to the ON position.
Wait at least 15 seconds for activation of the short circuit diagnostic code -4. Note: Monitor the "Active Diagnostic Codes" screen on Cat ET before installing the jumper wire and after installing the jumper wire.
Remove the jumper wire.
Turn the keyswitch to the OFF/RESET position. Expected Result:A short circuit diagnostic code -4 is active when the jumper wire is installed. An open circuit diagnostic code -3 is active when the jumper wire is removed.Results:
OK - The engine harness and the ECM are OK.Repair: Temporarily connect a new sensor to the harness, but do not install the new sensor in the engine. Check for an open circuit diagnostic code -3 while the new sensor is connected. If the open circuit diagnostic code -3 is not present, permanently install a new sensor. Clear any logged diagnostic codes.STOP
Not OK - The open circuit diagnostic code -3 remains active with the jumper in place. There appears to be an open circuit between the ECM and the sensor. Proceed to Test Step 6.Test Step 6. Check for Proper Operation of the ECM
Remove power from the ECM.
Check the operation of the