ENGINE AR 7N1534 - Caterpillar

Illustration 1 g03805054
Schematic for the active analog sensors
Test Step 1. Check for "Active" or "Logged" Diagnostic Codes
Connect Caterpillar Electronic Technician (ET) to the service tool connector.
Turn the keyswitch to the START 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 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
4
10Expected 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 10 diagnostic code is active.Repair: A 10 diagnostic code indicates an open in the voltage supply to a sensor. If the code is only present for one sensor, the open will be between the sensor connector and a splice. If the open is for two or more sensors the open will be before the splice for the voltage supply to those sensors. Repair the open in the wiring or connectors. Refer to the electrical schematic for the locations of splices in the harness.STOP
Not OK - A 3 code or a 4 code is active. Proceed to Test Step 2.Test Step 2. Check the 5 V 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.
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 approximately 5.0 0.5 VDC.Results:
OK - The supply voltage is approximately 5.0 0.5 VDC. An active 3 diagnostic code is present. Proceed to Test Step 3.
OK - The supply voltage is approximately 5.0 0.5 VDC. An active 4 diagnostic code is present. Proceed to Test Step 5.
Not OK - The supply voltage is not approximately 5.0 0.5 VDC.Repair: There is an open in the wiring or connectors between the suspect sensor and the ECM. Inspect the wiring and connectors.STOPTest Step 3. Check for Battery on the Signal Wire
Measure the voltage on the harness side of the sensor connector between pin B and pin C for the suspect sensor.Expected Result:The