0301732 JOHNSON PLUG,Oil hole

Table 1
Diagnostic Codes Table
Code and Description Conditions which Generate this Code System Response
110-3 Engine Coolant Temperature Sensor : Voltage Above Normal The engine's Electronic Control Module (ECM) detects signal voltage that is more than 4.9 VDC for eight seconds. The ECM has been powered for at least two seconds. The code is logged.
The alarm output is activated.
The shutdown output is activated.
The engine is shut down.
The value of the parameter is set to the last value from the sensor that is valid.
110-4 Engine Coolant Temperature Sensor : Voltage Below Normal The ECM detects signal voltage that is less than 0.2 VDC for eight seconds. The ECM has been powered for at least two seconds. System OperationUse this procedure to troubleshoot any suspect problems with the engine's coolant temperature sensor.The sensor signal for the passive sensor is routed from the ECM to terminal 1 of the sensor connector. The sensor return for the passive sensors is routed from the ECM to terminal 2 of the sensor connector.
Illustration 1 g01771633
Schematic for the passive analog sensor
Illustration 2 g01771693
Locations of the passive analog sensor (left front side engine view)
(1) Engine coolant temperature sensor
Illustration 3 g01771694
Locations of the connectors at the ECM junction box (left front engine view)
(2) J1/P1 ECM connectors
(3) Control harness connectors
Illustration 4 g01420865
Terminal locations at the P1 ECM connector for the passive sensor
(P1-3) Analog return
(P1-27) Engine coolant temperature
Illustration 5 g01771695
Terminal locations at the control harness connector for the passive sensor
(Terminal q) Engine coolant temperature
(Terminal r) Analog return
(Terminal s) Shield
Illustration 6 g01436505
Terminal locations at the connector for the passive analog sensor
(Terminal 1) Sensor signal
(Terminal 2) Analog return Test Step 1. Check for Diagnostic Codes that are Active or Logged
Turn the engine control to the OFF/RESET position. Remove electrical power from the engine.
Connect Caterpillar Electronic Technician (ET) to the service tool connector.
Restore electrical power to the engine. Turn the engine control to the STOP position.
Monitor the diagnostic codes on Cat ET. Check and record any diagnostic codes. Note: Wait at least 30 seconds in order for the diagnostic codes to become active.
Determine if a diagnostic code has occurred several times. Note: A diagnostic code that is logged several times is an indication of an intermittent problem. Most intermittent problems are the result of a poor connection between a socket and a pin in a connector or of a poor connection between a wire and a terminal.
Determine if the problem is active and related to one of the following failure modes for the analog passive sensor:
-3
-4
Turn the engine control to the OFF/RESET position. Remove electrical power from the engine. Expected Result:A diagnostic code is not active.Results:
OK - A diagnostic code is not active.Repair: There may be an intermittent electrical problem in the harness or in a connector. If an intermittent electrical problem is suspected, refer to Troubleshooting, "Electrical Connectors - Inspect" for information that is related to troubleshooting these problems.STOP
Active -3 - An active -3 diagnostic code is present. The ECM detects an open in the circuit for the sensor. Proceed to Test Step 2.
Active -4 - An active -4 diagnostic code is present. Proceed to Test Step 4.Test Step 2. Check for Battery Voltage on the Signal Wire
Restore electrical power to the engine. Turn the engine control to the STOP position.
Measure the voltage on the harness side of the sensor connector between pin 1 and engine ground for the coolant temperature sensor.
Turn the engine control to the OFF/RESET position. Remove electrical power from the engine. Expected Result:The signal voltage is less than battery voltage.Results:
OK - The signal voltage is less than battery voltage. The circuit for the signal is not shorted to the +Battery. Proceed to Test Step 3.
Not OK - The signal voltage is equal to battery voltage.Repair: There is a short circuit to the +Battery in the harness. Repair the wiring harness or replace the wiring harness. Verify that the repair has resolved the original problem.STOPTest Step 3. Create a Short Circuit at the Connector for the Coolant Temperature Sensor
Disconnect the harness connector for the coolant temperature sensor.
Fabricate a jumper wire that is long enough to create a test circuit across the harness side of the sensor connector. Crimp connector pins to each end of the jumper wire.
Install the jumper wire between terminal 1 (sensor signal) and terminal 2 (sensor return) at the sensor connector.
Restore electrical power to the engine. Turn the engine control to the STOP position.
Access the "Active Diagnostic Code" screen on Cat ET. Check for an active -4 diagnostic code for the coolant temperature sensor. Wait at least 30 seconds in order for the diagnostic codes to become active.
Turn the engine control to the OFF/RESET position. Remove electrical power from the engine. Expected Result:A -4 diagnostic code is now active for the coolant temperature sensor.Results:
OK - A -4 diagnostic code became active with the jumper wire in place.Repair: A -3 diagnostic code was active before creating the short at the sensor connector. A -4 diagnostic code became active after creating the short at the sensor connector. The wiring between the ECM and the sensor connector is OK. Perform the following procedure:Temporarily connect a new sensor to the harness, but do not install the new sensor in the engine. Verify that there are no active diagnostic codes for the sensor. If there a