DRIVER 1123971 - Caterpillar

Illustration 2 g03767991
(12) Line heater relay
(13) Main power relay
Illustration 3 g03689199
Not all connectors are shown, refer to the appropriate schematic
Table 2
Associated Codes
J1939 Code CDL Code
3363-5 3126-5
3363-6 3126-6 Complete the procedure in the order in which the steps are listed.
Table 3
Troubleshooting Test Steps Values Results
1. Determine the Diagnostic Code
A. Establish communication between Cat® Electronic Technician (ET) and the engine Electronic Control Module (ECM) . Refer to Troubleshooting, "Electronic Service Tools", if necessary.
B. Download the "Warranty Report" from the engine ECM before performing any troubleshooting or clearing diagnostic trouble codes.
C. Establish communication between Caterpillar Electronic Technician (ET) and the Diesel Exhaust Fluid Controller (DCU) .
D. Look for an active or logged -5 code or -6 code.
Diagnostic Trouble Codes
Result: There is an associated code active or logged.
Repair: Troubleshoot the associated codes. Refer to Troubleshooting, "Diagnostic Trouble Codes or Event Codes" for the proper procedure.
Result: There is an active or there is a logged -5 code other than a 3822-5 or 5491-5 code.
Proceed to Test Step 2.
Result: There is an active or there is a logged 3822-5 or 5491-5 code.
Proceed to Test Step 4.
Result: There is an active or there is a logged -6 code.
Proceed to Test Step 5.
2. Check for Power at Aftertreatment 1 Diesel Exhaust Fluid Line Heater Relay
A. Turn the keyswitch to the OFF position. Allow 2 minutes to elapse before proceeding.
B. Remove the heated line relay from the harness.
C. Verify that the harness connector is free of debris and free of corrosion.
D. Turn the keyswitch to the ON position.
E. Check for battery voltage between terminal 1 of the heated line relay and a known good ground .
Battery Voltage
Result: The voltage between terminal 1 and a good ground source is equal to battery voltage.
Turn the keyswitch to the OFF position. Allow 2 minutes to elapse, reinstall the relay. Proceed to Test Step 3.
Result: The voltage between terminal 1 and a good ground source is not equal to battery voltage.
Repair: Refer to the schematic and troubleshoot the power source from the VLPM.
3. Check the Wiring for an Open Circuit
A. Disconnect the suspect line heater from the aftertreatment harness.
B. Verify that the harness connector is free of debris, free of corrosion and securely connected.
C. Connect a jumper wire between the terminals of the harness connector for the suspect heated line. The heated line is replaced with a short circuit.
D. Turn the keyswitch to the ON position.
E. Connect to the "Diesel Exhaust Fluid Controller #1" ECM using Cat ET.
F. Go to "Diagnostic Tests" and perform a "DEF Heated Line Test".
Short Circuit
Result: A -5 code became active during the electrical checkout.
The DCU did not detect the jumper wire. There is an open circuit between the heated line relay and the DCU connector.
Repair: Turn the keyswitch to the OFF position. Allow 2 minutes to elapse, replace the heated line relay.
Proceed to Test Step 4.
Result: A -6 code is activated during the electrical checkout. The DCU detected the jumper wire. There is a problem with the heated line.
Repair: Replace the heated line.
Turn the keyswitch to the off