PLUG-FELT 1255835 - Caterpillar

System Operation Description:Use this procedure to troubleshoot diagnostic codes for open circuits or short circuits for the circuits of these parameters:
Filtered engine oil pressure
Air inlet pressure
Intake manifold air temperature
Engine oil temperature
Unfiltered engine oil pressure
Fuel quality
Compressor discharge pressureThis procedure covers the following diagnostic codes:
100-3 Engine Oil Pressure Sensor : Voltage Above Normal
100-4 Engine Oil Pressure Sensor : Voltage Below Normal
102-3 Boost Pressure Sensor : Voltage Above Normal
102-8 Boost Pressure Sensor : Abnormal Frequency, Pulse Width, or Period
106-3 Air Inlet Pressure Sensor : Voltage Above Normal
106-4 Air Inlet Pressure Sensor : Voltage Below Normal
172-3 Intake Manifold Air Temperature Sensor : Voltage Above Normal
172-4 Intake Manifold Air Temperature Sensor : Voltage Below Normal
175-3 Engine Oil Temperature Sensor : Voltage Above Normal
175-4 Engine Oil Temperature Sensor : Voltage Below Normal
542-3 Engine Oil Pressure Sensor - Before Oil Filter : Voltage Above Normal
542-4 Engine Oil Pressure Sensor - Before Oil Filter : Voltage Below Normal
2449-5 Fuel Quality Sensor : Current Below Normal
2449-6 Fuel Quality Sensor : Current Above Normal
2852-3 Compressor Discharge Pressure Sensor : Voltage Above Normal
2852-4 Compressor Discharge Pressure Sensor : Voltage Below NormalNote: The air inlet pressure sensor may be a PWM sensor or an analog sensor. Determine the type of sensor before you use this procedure. The air inlet pressure sensor is a PWM sensor if a wire is installed in P1-10. Refer to Troubleshooting, "Sensor Signal (PWM) - Test" if the air inlet pressure sensor is a PWM sensor. The air inlet pressure sensor is an analog sensor if a wire is installed in terminal P1-15 or P5-15.A -3 code is probably caused by a problem in an engine harness. There may be an open circuit in a harness, or a short circuit to a positive voltage source in a harness. The next likely cause is a sensor problem. The least likely cause is a problem with a control module.A -4 code is probably caused by a short circuit to ground in an engine harness. The next likely cause is a sensor problem. The least likely cause is a problem with a control module.Logged diagnostic codes provide a historical record. Before you begin this procedure, use Caterpillar Electronic Technician (ET) to print the logged codes to a file.This troubleshooting procedure may generate additional diagnostic codes. Keep your mind on correcting the cause of the original diagnostic code. Clear the diagnostic code after the problem is resolved.
Illustration 1 g01319747
Schematic for the active analog inputsTest Step 1. Inspect the Electrical Connectors and Wiring
Remove the electrical power from the engine.Note: For the following steps, refer to Troubleshooting, "Electrical Connectors - Inspect".
Thoroughly inspect each of the following connectors:
J1/P1 connectors
J5/P5 connectors
J6/P6 connectors
J7/P7 connectors
J9/P9 connectors
Check the torque of the allen head screws for the ECM connectors.
If you are troubleshooting a problem with an analog sensor, perform a 45 N (10 lb) pull test on each of the wires that are associated with the circuit for the analog sensors.
If you are troubleshooting a problem with an analog sensor, check the harness and wiring for abrasion and for