CLIP 3S8664 - Caterpillar

Use this procedure to troubleshoot a problem with the Diesel Exhaust Fluid (DEF) tank sensor. Also, use this procedure if one of the following diagnostic codes is active or easily repeated.
Table 1
J1939 Code and Description CDL Code and Description Comments
4367-3
Aftertreatment #1 DEF Quick Thaw Tank Level : Voltage Above Normal 3131-3
Aftertreatment #1 DEF Tank #2 Level Sensor : Voltage Above Normal The Electronic Control Module (ECM) detects signal voltage that is not in the acceptable range.
The code is logged.
4367-4
Aftertreatment #1 DEF Quick Thaw Tank Level : Voltage Below Normal 3131-4
Aftertreatment #1 DEF Tank #2 Level Sensor : Voltage Below Normal The ECM detects signal voltage that is not in the acceptable range.
The code is logged.
4368-3
Aftertreatment #1 DEF Tank #2 Temperature : Voltage Above Normal 3135-3
Aftertreatment #1 DEF Tank #2 Temperature Sensor : Voltage Above Normal The ECM detects signal voltage that is not in the acceptable range.
The code is logged.
4368-4
Aftertreatment #1 DEF Tank #2 Temperature : Voltage Below Normal 3135-4
Aftertreatment #1 DEF Tank #2 Temperature Sensor : Voltage Below Normal The ECM detects signal voltage that is not in the acceptable range.
The code is logged. The signal for the Diesel Exhaust Fluid (DEF) tank level sensor is routed to terminal 1 of the tank header unit. The signal for the DEF tank temperature sensor is routed to terminal 3 of the tank header unit. The sensor return is shared and is routed to terminal 2 of the tank header unit. The Electronic Control Module (ECM) provides short circuit protection for the internal power supply. A short circuit to the battery will not damage the internal power supply.
Illustration 1 g01240891
(1) DEF level sensor signal
(2) Sensor return
(3) DEF tank temperature signal
Illustration 2 g06136353
Table 2
Troubleshooting Test Steps Values Results
1. Check for Codes
A. Turn the DC breaker, located in the power distribution box, to the ON position.
B. Connect Cat® Electronic Technician (ET) to the service tool connector.
C. Determine if a code is active or logged.
Codes
Result: A -3 code is active.
Proceed to Test Step 2.
Result: A -4 code is active.
Proceed to Test Step 3.
2. Create a Short at the Sensor Connector
A. Verify that the wiring harness connector is free of debris, free of corrosion, and securely connected.
B. Install a jumper wire between the appropriate signal and return wire at the sensor connector to create a short.
C. Turn the DC breaker, located in the power distribution box, to the ON position.
D. Connect Cat ET.
E. Use