CYLINDER AS 4610649 - Caterpillar

Table 1
Diagnostic Codes Table    
J1939 Code    Code Description    Comments    
1761-3     Aftertreatment 1 Diesel Exhaust Fluid Tank Level : Voltage Above Normal     The ECM detects signal voltage that is not in the acceptable range.
The code is logged.    
1761-4     Aftertreatment 1 Diesel Exhaust Fluid Tank Level : Voltage Below Normal     The ECM detects signal voltage that is not in the acceptable range.
The code is logged.    
3031-3     Aftertreatment 1 Diesel Exhaust Fluid Tank Temperature : Voltage Above Normal     The ECM detects signal voltage that is not in the acceptable range.
The code is logged.    
3031-4     Aftertreatment 1 Diesel Exhaust Fluid Tank Temperature : Voltage Below Normal     The ECM detects signal voltage that is not in the acceptable range.
The code is logged.    The 5 VDC signal for the Diesel Exhaust Fluid (DEF) tank level sensor is routed to terminal 1 of the tank header unit. The 5 VDC 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 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 g03359107
Not all connectors are shown, refer to the appropriate schematicThe tank header unit houses the DEF tank temperature and the DEF tank level sensors. The sensors are not serviceable individually.
Table 2
Troubleshooting Test Steps    Values    Results    
1. Check for Diagnostic Codes
A. Establish communication between the electronic service tool and the Diesel Exhaust Fluid Controller (DCU). Refer to Troubleshooting, "Electronic Service Tools", if necessary.
B. Turn the keyswitch to the ON position.
C. Look for "-3" or " -4" active or logged codes.
   
Diagnostic code    
Result: A -3 diagnostic code is active.
Proceed to Test Step 2.
Result: A -4 diagnostic code is active.
Proceed to Test Step 3.
   
2. Create a Short at the Sensor Connector
A. Verify that the 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 in order to create a short.
C. Turn the keyswitch to the ON position.
D. Monitor the diagnostic codes on the electronic service tool. Check for an active -4 diagnostic code for the suspect sensor.
E. Turn the keyswitch to the OFF position.    
Short created    
Result: A -4 diagnostic code became active after creating the short at the sensor connector.
The wiring is OK. Replace the DEF tank header assembly. Refer to the Disassembly and Assembly manual.
Verify that the problem is resolved by cycling the keyswitch to the OFF position for 2 minutes.