RING-BACKUP 4415673 - Caterpillar

Use this procedure to troubleshoot any suspect problems with the following sensors:
Coolant temperature sensor
Engine oil pressure sensor
Atmospheric pressure sensor
Intake manifold pressure sensor
Illustration 1 g01652647
Illustration 2 g01657635
(10) + 8 VDC (20) Coolant temperature (25) Boost pressure (26) Coolant level (27) Oil pressure (30) + 5 VDC (34) Atmospheric pressure (35) Analog return (40) Rack positionThe supply voltage is routed to terminal (A) of each sensor connector. The sensor return is routed to terminal (B) of each sensor connector. The sensor signal is routed to terminal (C) of each sensor connector. The ECM provides short circuit protection for the internal power supply. A short circuit to the battery will not damage the internal power supply.
Illustration 3 g01159881
Sensor connector (A) 5 V sensor supply (B) Sensor return (C) SignalTest Step 1. Check for Active Diagnostic Codes or Logged Diagnostic Codes
Connect Caterpillar Electronic Technician (ET) to the service tool connector.
Turn the engine control switch to the ON 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:
03
04Expected 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 04 diagnostic code is active. Proceed to Test Step 2.Test Step 2. Disconnect the Sensor and Check for an Open Circuit Diagnostic Code
Disconnect the suspect sensor.
View active diagnostic codes on CAT ET.Note: Wait at least 30 seconds in order for the diagnostic codes to become active.Expected Result:An active diagnostic code (03) appears for the disconnected sensor.Results:
OK - An active diagnostic code (03) appears for the disconnected sensor.Repair: There is a short in the sensor or the connector. Repair the connector. If the problem still exists, replace the sensor.STOP
NOT OK - An active diagnostic code (03) does not appear for the disconnected sensor. Proceed to Test Step 3.Test Step 3. Create a Short at the Sensor Connector
Turn the engine control switch to the OFF position.
Disconnect the suspect sensor.
Use a wire jumper in order to create a short between terminal (C) and terminal (B) at the sensor connector.
Turn the engine control switch to the ON position.
Monitor the diagnostic codes on Cat ET. Check for an active 04 diagnostic code for the suspect sensor.Note: Wait at least 30 seconds in order for the diagnostic codes to become active.
Turn the engine control switch to the OFF position.Expected Result:A 04 diagnostic code is now active for the suspect sensor(s).Results:
OK - A 03 diagnostic code was active before