VALVE GP-BANK 4 2500544 - Caterpillar

Table 1
J1939 Code Code Description Comments
4374-5 Aftertreatment #1 DEF Pump #1 Motor Speed : Current Below Normal This code indicates there is problem with the DEF pump or the wiring harness.
4374-6 Aftertreatment #1 DEF Pump #1 Motor Speed : Current Above Normal This code indicates there is problem with the DEF pump or the wiring harness. Note: 372-5260 Test Kit is required for completing this procedure.
Illustration 1 g03185736
Table 2
Troubleshooting Test Steps Values Results
1. Check for Opens in the Pump Electronic Tank Unit (PETU) Wiring Harness for the DEF Pump Motor Circuit
A. Turn the keyswitch to the "OFF" position. The keyswitch must be OFF for 2 minutes to allow the DEF pump to purge, reset the code, and reset the DCU.
B. Disconnect the PETU wiring harness from the DEF pump and the Diesel Exhaust Fluid Controller (DCU).
C. Connect the 398-5063 Break-out Connector to the DCU connector.
Connect the 398-5056 Break-out Connector to the pump connector.
The connectors must be used to prevent damage to the DCU and pump connectors.
D. Measure the resistance between terminal 9 (PWM +) on the DEF pump connector and terminal 46 (PWM +) on the 86 pin DCU connector.
E. Measure the resistance between terminal 8 (PWM -) on the DEF pump connector and terminal 26 (PWM -) on the 86 pin DCU connector.
F. Measure the resistance between terminal 10 (PWM SIGNAL) on the DEF pump connector and terminal 24 (PWM SIGNAL) on the 86 pin DCU connector.
Open circuit
Result: There was less than 10 Ohms of resistance on all of the DEF pump motor circuit wires.
Proceed to Test Step 2.
Result: There was more than 10 Ohms of resistance on any one of the DEF pump