CONE 2P8482 - Caterpillar

System Operation Description:Use this procedure to troubleshoot the system when one of the following diagnostic codes is active or easily repeated:
262-03 5 Volt Sensor DC Power Supply short to +batt
262-04 5 Volt Sensor DC Power Supply short to groundThe Electronic Control Module (ECM) supplies a regulated voltage of 5.0 0.2 VDC to the following sensors:
Coolant temperature sensor
Aftercooler temperature sensor
Unfiltered engine oil pressure sensor
Filtered engine oil pressure sensor
Left turbocharger inlet pressure sensor
Right turbocharger inlet pressure sensor
Atmospheric pressure sensor
Crankcase pressure sensor
Turbocharger outlet pressure sensor
Unfiltered fuel pressure sensor
Filtered fuel pressure sensorThe supply for the +5 V engine pressure sensor is routed from the ECM to terminal A of each pressure sensor connector. The sensor common from the ECM connector goes to terminal B of each sensor connector. The sensor supply is output short circuit protected. A short circuit to the battery will not damage the circuit inside the ECM.Note: The sensors are not protected from overvoltage. A short from the supply line to the +Battery may damage the sensors. If the CID-FMI 262-03 is logged, it is possible that all of the sensors have been damaged. Repair the sensor supply and check for any "ACTIVE" sensor diagnostic codes in order to determine if a sensor has failed.The +5 V diagnostic code is probably caused by a short circuit to ground or a short circuit to another voltage source in the harness.
Illustration 1 g01161442
Schematic
Illustration 2 g01161474
P1 ECM connector
(P1-2) Analog sensor power
(P1-3) Analog sensor common
(P1-6) Aftercooler temperature
(P1-7) Coolant temperature
(P1-16) Filtered oil pressure
(P1-17) Unfiltered oil pressure
(P1-18) Analog sensor power
(P1-35) Analog sensor common
(P1-24) Filtered fuel pressure
(P1-25) Unfiltered fuel pressure
Illustration 3 g01161487
P2 ECM connector
(P2-3) Atmospheric pressure
(P2-36) Turbocharger outlet pressure
(P2-38) Left turbocharger inlet pressure
(P2-39) Right turbocharger inlet pressure
(P2-46) Crankcase pressure
Illustration 4 g01094844
Sensor connector
Illustration 5 g01142488
Typical sensor locations
(1) Engine oil pressure sensor
Illustration 6 g01161501
Typical sensor locations
(2) Turbocharger inlet pressure sensor
(3) Boost pressure sensor
(4) Filtered fuel pressure sensor
(5) Inlet manifold pressure sensor
(6) Atmospheric pressure sensor
(7) Unfiltered fuel pressure sensor Test Step 1. Inspect Electrical Connectors and Wiring
Turn the battery disconnect switch to the OFF position.
Thoroughly inspect the J1/P1 ECM connector and the J2/P2 ECM connector. Inspect all of the connectors that are associated with the circuit. Refer to Troubleshooting, "Inspecting Electrical Connectors" for details.
Perform a 45 N (10 lb) pull test on each of the wires in the ECM connectors that are associated with the circuit.
Check the ECM connector (allen head screw) for the proper torque. Refer to Troubleshooting, "Inspecting Electrical Connectors" for details.
Check the harness and wiring for abrasion and for pinch points from the sensors back to the ECM. Expected Result:All connectors, pins and sockets are completely coupled and/or inserted and the harness and wiring are free of corrosion, of abrasion and of pinch points.Results:
OK - The harness and connectors appear to be OK. Proceed to Test Step 3.
Not OK - There is a problem with 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