5031637 JOHNSON SCREW

Illustration 1 g01119633
Schematic
Illustration 2 g01024457
P2 ECM connector
(P2-15) Boost pressure sensor
(P2-17) Sensor common
(P2-28) Engine oil pressure sensor
(P2-40) Fuel pressure sensor
(P2-57) Atmospheric pressure sensor
(P2-72) +5 V Supply
Illustration 3 g01119636
C13 Sensor locations
(1) Atmospheric pressure sensor
(2) Fuel pressure sensor
(3) Engine oil pressure sensor
(4) Boost pressure sensor
Illustration 4 g01252438
C15 and C18 Sensor locations
(5) Boost pressure sensor
(6) Fuel pressure sensor
(7) Atmospheric pressure sensor
(8) Engine oil pressure sensor
Illustration 5 g01094844
Sensor connector
Test Step 1. Inspect Electrical Connectors and Wiring
Turn the keyswitch to the OFF position.
Thoroughly inspect the J1/P1 ECM connector and the J2/P2 ECM connector. Thoroughly inspect the connectors for each analog sensor. Refer to Troubleshooting, "Electrical Connectors - Inspect" for details.
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.
Check the ECM connector (allen head screw) for the proper torque. Refer to Troubleshooting, "Electrical Connectors - Inspect" for details.
Check the harness and wiring for abrasions and for pinch points from the sensors back 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 harness and wiring are OK. Proceed to Test Step 2.
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 2. Check for "Active" or "Logged" Diagnostic Codes
Connect Caterpillar Electronic Technician (ET) to the service tool connector.
Restore electrical power to the ECM.
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 bad connection between a socket and a pin in a connector or a bad connection between a wire and a terminal. The problem may be caused by moisture, corrosion, or wear.
Determine if the problem is active and related to one of the following diagnostic codes:
-3
-4Expected Result:A diagnostic code is not active.Results:
OK - A diagnostic code is not active.Repair: The problem may be intermittent. If the problem is intermittent, refer to Troubleshooting, "Electrical Connectors - Inspect".STOP
Not OK - A diagnostic code is active. Proceed to Test Step 3.Test Step 3. Check the 5 Volt Supply Voltage at the Sensor Connector
Do not disconnect the suspect connector.
Connect a voltmeter between pin A and pin B on the sensor side of the connector for the suspect sensor.
Measure the voltage between pin A and pin B for the suspect sensor(s).
Wiggle the harness while you monitor the voltage on the voltmeter. Perform the 45 N (10 lb) pull test on each wire in the circuit. Each terminal and each connector should easily withstand 45 N (10 lb) of tension and each wire should remain in the connector body. This test checks whether the wire was properly crimped in the terminal and whether the terminal was properly inserted into the connector. Expected Result:The supply voltage is 5.0 0.5 VDC.Results:
OK - The voltage is 5.0 0.5 VDC. An active -3 diagnostic code is present. Proceed to Test Step 4.
OK - The voltage is 5.0 0.5 VDC. An active -4 diagnostic code is present. Proceed to Test Step 6.
Not OK - The voltage is not 5.0 0.5 VDC. Proceed to Test Step 8.Test Step 4. Check for a Short to the +Battery at the Sensor Connector
Measure the voltage on the harness side of the sensor connector between pin B and pin C for the suspect sensor(s). Expected Result:The voltage is less than battery voltage.Results:
OK - The voltage is less than battery voltage. Proceed to Test Step 5.
Not OK - The voltage is equal to battery voltage.Repair: There is a short in the harness to the +Battery. Repair the wiring.STOPTest Step 5. Create a Short at the Sensor Connector
Remove electrical power from the