COVER 6G1539 - Caterpillar

Illustration 3 g03374231
Fuel rail pressure sensor
(1) Ground
(2) Signal
(3) 5 VDC Supply
Illustration 4 g01170310
Typical example of an engine pressure sensor
(1) 5 VDC Supply
(2) Ground
(3) Signal
Table 2
Troubleshooting Test Steps Values Results
1. Inspect Electrical Connectors and Wiring
A. Thoroughly inspect the terminal connections on the P2/J2 ECM connectors and the engine pressure sensors.
Refer to Troubleshooting, "Electrical Connectors - Inspect".
B. Perform a 45 N (10 lb) pull test on each of the wires in the ECM connector and the sensor connectors that are associated with the active diagnostic code.
C. Check the screw for the ECM connector for the correct torque of 6 N m (53 lb in).
D. Check the harness for corrosion, abrasion, and pinch points from the engine pressure sensors to the ECM.
Loose connection or damaged wire
Result: There is a fault in a connector or the wiring.
Repair: Repair any faulty connectors or replace the wiring harness. Ensure that all the seals are properly in place and ensure that the connectors are correctly coupled.
Use the electronic service tool to clear all logged diagnostic codes and verify that the repair eliminates the fault.
Result: All connectors, pins, and sockets are correctly coupled and/or inserted. The harness is free of corrosion, abrasion, and pinch points.
Proceed to Test Step 2.
2. Check For Active Diagnostic Codes
A. Turn the keyswitch to the OFF position.
B. Connect the electronic service tool to the diagnostic connector.
C. Turn the keyswitch to the ON position. Wait at least 10 seconds for activation of the diagnostic codes.
D. Verify if any of the diagnostic codes that are listed in Table 1 are active.
E. Turn the keyswitch to the OFF position.
Diagnostic codes
Result: There are no active diagnostic codes for the active sensors.
Repair: If there are logged diagnostic codes for the active sensors, the fault may be intermittent.
Refer to Troubleshooting, "Electrical Connectors - Inspect" to identify intermittent faults.
Result: A diagnostic code that is listed in Table 1 is active.
Proceed to Test Step 3.
3. Check the Supply Voltage at the Sensor Connector
A. Turn the keyswitch to the OFF position.
B. Disconnect the connector for the suspect sensor.
C. Turn the keyswitch to the ON position. Do not start the engine.
D. Measure the voltage between the supply terminal and the ground terminal on the harness connector for the suspect sensor. The voltage measurement should be 5.0 0.2 VDC.
E. Turn the keyswitch to the OFF position.
F. Reconnect the sensor.
4.8 VDC to 5.2 VDC
Result: The voltage measurement is not within the expected range. The fault is in the supply wire or the ground wire in the engine wiring harness.
Repair: Repair the faulty wiring or replace the faulty wiring.
Use the electronic service tool to clear all logged diagnostic codes. Return the engine to service.
Result: The voltage measurement is within the expected range - The correct supply voltage is reaching the sensor.
Proceed to Test Step 4.
4. Check the Type of Diagnostic Code that is Active
A. Turn the keyswitch to the ON position. Wait at least 10 seconds for activation of the diagnostic codes.
B. Use the electronic service tool to check for active diagnostic codes. Record all active