GASKET KIT 1361112 - Caterpillar

Table 1 lists the diagnostic codes for the Diesel Exhaust Fluid (DEF) pump pressure sensor circuit.
Table 1
Diagnostic Trouble Codes for the DEF Pump Pressure Sensor
J1939 Code CDL Code Code Description
(code descriptions may vary) Comments
4334-3 3090-3 Aftertreatment #1 SCR Dosing Reagent Absolute Pressure : Voltage Above Normal There is excessive voltage on the signal wire between the Diesel Exhaust Fluid Controller (DCU) and the DEF pump.
or
There is an open circuit on the supply, signal, or return wire.
The code is logged.
4334-4 3090-4 Aftertreatment #1 SCR Dosing Reagent Absolute Pressure : Voltage Below Normal There is low voltage on the signal wire between the DCU and the DEF pump pressure sensor.
The code is logged.
Follow the troubleshooting procedure to identify the root cause of the problem.
Table 2
Required Tools
Tool Part Number Part Description Qty
A 372-5260 Test Kit 1
Illustration 1 g03811016
Illustration 2 g03416459
View of the pin locations for the DEF pump on the 86-pin DCU connector
(17) DEF pump pressure sensor signal
(18) DEF pump pressure sensor ground
(19) DEF pump pressure sensor 5 VDC supply
Illustration 3 g03416460
Pin location on the DEF pump connector
(2) Pressure sensor supply
(3) Pressure sensor signal
(4) Pressure sensor returnComplete the procedure in the order in which the steps are listed.
Table 3
Troubleshooting Test Steps Values Results
1. Inspect Electrical Connectors and Wiring
A. Inspect the 86-pin DCU connector.
B. Inspect the connector for the DEF pump.
C. Perform a 45 N (10 lb) pull test on each of the wires in the DCU connector and the connector for the DEF pump.
D. Check all the wiring associated with the DEF pump for abrasions and pinch points.
Damaged wire or connector
Result: A damaged wire or damaged connector was not found.
Proceed to Test Step 2.
Result: A damaged wire or damaged connector was found.
Repair: Repair the damaged wire or the damaged connector.
Use the electronic service tool to clear all logged diagnostic codes. Verify that the repair eliminates the fault.
2. Determine the Diagnostic Code
A. Establish communication between the electronic service tool and the engine Electronic Control Module (ECM). Refer to Troubleshooting, "Electronic Service Tools"
B. Download the "Warranty Report" from the engine ECM before performing any troubleshooting or clearing diagnostic trouble codes.
C. Establish communication between the electronic service tool and the Dosing Control Unit (DCU) .
D. Check for active or logged codes.
Diagnostic trouble codes
Result: There is an active or logged 4334-3, 3090-3, 4334-4 or 3090-4 diagnostic code.
Proceed to Test Step 3.
3. Check for an Open Circuit in the Pump Electronic Tank Unit (PETU) Wiring Harness for the DEF Pump Pressure Sensor Circuit
A. Turn the keyswitch to the OFF position for 2 minutes. The keyswitch must be OFF for 2 minutes to allow the DEF pump to purge, reset the code, and reset the Diesel Exhaust Fluid Controller (DCU).
B. Disconnect the PETU wiring harness from the DEF pump and the DCU.
C. Connect the 398-5063 Break-out Connector to the DCU connector. Connect the 398-5056 Break-out Connector to the DEF pump connector.
Note: The connectors must be used to prevent damage to the DCU and DEF pump connector.
D. Measure the resistance between terminal 2 (SUPPLY) on the DEF