ENGINE G 0694421 - Caterpillar

Table 1
Diagnostic Trouble Codes for the Aftertreatment Power Relay
J1939 Code CDL Code Code Description
(code descriptions may vary) Comments
5965-5 3838-5 Aftertreatment #1 DEF Control Module Relay Control : Current Below Normal The Electronic Control Module (ECM) detects a low current condition in the aftertreatment power relay circuit.
5965-6 3838-6 Aftertreatment #1 DEF Control Module Relay Control : Current Above Normal The ECM detects a high current condition in the aftertreatment power relay circuit.
Follow the troubleshooting procedure to identify the root cause of the fault.
Illustration 1 g06206555
Schematic diagram for the aftertreatment power relay
Not all connectors are shown. Refer to the appropriate Electrical Schematic.
Complete the procedure in the order in which the steps are listed.
Table 2
Troubleshooting Test Steps Values Results
1. Inspect Electrical Connectors and Wiring
A. Check that the fuses are not blown.
B. Inspect the terminals on the aftertreatment power relay. Refer to Troubleshooting, "Electrical Connector - Inspect" for details.
C. Perform a 45 N (10 lb) pull test on each of the wires in the ECM connector that are associated with the aftertreatment power relay.
D. Check the screw for the ECM connector for the correct torque of 6 N m (53 lb in).
E. Check the harness for abrasion and pinch points from the aftertreatment power relay back to the ECM.
Loose connection or damaged wire
Result: There is a fault in a connector or the wiring.
Repair: Repair any faulty connectors or replace the wiring harness. Ensure that all the seals are properly in place and ensure that the connectors are correctly coupled.
Replace any blown fuses.
Use the electronic service tool to clear all logged diagnostic codes.
Use the electronic service tool to perform the "Aftertreatment System Functional Test" to verify that the repair eliminates the fault.
Result: All connectors, pins, and sockets are correctly coupled and/or inserted. The harness is free of corrosion, abrasion, and pinch points. The fuses are not blown.
Proceed to Test Step 2.
2. Check for Active Diagnostic Codes
A. Connect the electronic service tool to the diagnostic connector.
B. Turn the keyswitch to the ON position.
Note: Do not start the engine.
C. Use the electronic service tool to check for active diagnostic codes.
Diagnostic codes
Result: Diagnostic code 5965-5 or 3838-5 is active or recently logged.
Proceed to Test Step 3.
Result: Diagnostic code 5965-6 or 3838-6 is active or recently logged.
Proceed to Test Step 5.
3. Create a Short Circuit at the Relay Connector
A. Turn the keyswitch to the OFF position.
B. Remove the aftertreatment power relay.
C. Fabricate a jumper wire. Install the jumper wire between terminal 85 and terminal 86 on the harness connector for the aftertreatment power relay.
D. Turn the keyswitch to the ON position.
E. Use the electronic service tool to check for active diagnostic codes. Wait at least 30 seconds for activation of the diagnostic codes.
F. Turn the keyswitch to the OFF position and remove the jumper wire.
Diagnostic code
Result: A 5965-6 or 3838-6 diagnostic code is active with the jumper installed.
Repair: Install a replacement start relay.
Use the electronic service tool to clear all logged diagnostic codes and verify that the repair eliminates the fault.
Result: The 5965-5 or 3838-5 diagnostic code is