CAP 0963100 - Caterpillar

System Operation Description:This procedure covers the following codes:
Table 1
Diagnostic Trouble Codes for the Fuel Rack Solenoid Position Sensor
J1939 Code Description Notes
733-3 Engine Rack Position Sensor : Voltage Above Normal The Electronic Control Module (ECM) detects the following conditions:
The signal voltage from the fuel rack solenoid position sensor is greater than 4.5 VDC for at least 1 second.
The keyswitch is ON for at least 2 seconds.
The warning lamp will flash. The shutdown lamp will come on.
The engine will shut down. The engine will not restart.
733-4 Engine Rack Position Sensor : Voltage Below Normal The ECM detects the following conditions:
The signal voltage from the fuel rack solenoid position sensor is less than 0.5 VDC for at least 2 seconds.
The keyswitch is ON for at least 2 seconds.
The warning lamp will flash. The shutdown lamp will come on.
The engine will shut down. The engine will not restart. The position sensor is an integral part of the fuel rack solenoid. If the following procedure indicates a fault with the position sensor, then the entire solenoid must be replaced.The following background information is related to this procedure:The ECM supplies 5 VDC to terminal "B" of the fuel rack solenoid position sensor connector. The sensor common from the ECM connector goes to terminal "A" of the fuel rack solenoid position sensor connector. The sensor supply is output short circuit protected. A short circuit to the battery will not damage the circuit inside the ECM. The signal voltage from terminal "C" of the fuel rack solenoid position sensor connector is supplied to P2:49 on the ECM connector.
Illustration 1 g03330725
Schematic for the fuel rack position sensor
Illustration 2 g03330798
Typical view of the pin locations on the P2 connector for the position sensors
(48) Fuel rack solenoid position sensor ground
(49) Fuel rack solenoid position sensor 5 VDC supply
(50) Fuel rack solenoid position sensor signal
Illustration 3 g03330886
View of the harness connector for the fuel rack solenoid position sensor
(A) Fuel rack position sensor ground
(B) Fuel rack position sensor 5 VDC supply
(C) Fuel rack solenoid position sensor signal Test Step 1. Verify All Active and Recently Logged Diagnostic Codes
Turn the keyswitch to the ON position. Wait at least 10 seconds for activation of the diagnostic codes.
Verify if any of the diagnostic codes that are listed in Table 1 are active or recently logged. Results:
One or more of the preceding diagnostic codes are active or recently logged. - Proceed to Test Step 2.
None of the preceding diagnostic codes are active or recently logged. - Repair: The fault may be intermittent. Refer to Troubleshooting, "Electrical Connectors - Inspect" in order to identify intermittent faults.STOPTest Step 2. Inspect Electrical Connectors And Wiring
Thoroughly inspect the terminal connections on the P2/J2 ECM connectors.
Thoroughly inspect the connector for the fuel rack solenoid position sensor.
Refer to Troubleshooting, "Electrical Connectors - Inspect".
Perform a 45 N (10 lb) pull test on each of the wires in the ECM connector that are associated with the fuel rack solenoid position sensor.
Check the harness for abrasions and for pinch points from the fuel rack solenoid position sensor