Diagnostic Test

WARNING: This page is about a different car, the 2017 RAM 2500 HD. However, it is still accessible from the selected car via links, so may be relevant.

VERIFY THE DTC IS ACTIVE
NOTE:
The appropriate trailer must be present for the results of this test to be valid.

NOTE:
This DTC must be active for the results of this test to be valid.
1. Connect the trailer to the vehicle.
2. Turn the ignition on.
3. With the scan tool, record and erase DTCs.
4. Cycle the ignition switch from off to on.
5. With the scan tool, read DTCs.
  Is the status Active for this DTC?
  
  Yes
  - Go To 2
  No
  - Go To 6
TRAILER WIRING/BRAKES
1. Turn ignition off.
2. Disconnect the trailer or trailer simulator from the vehicle.
3. Turn ignition on.
4. With the scan tool, record and erase DTCs.
5. Cycle the ignition switch from off to on.
  Does the EVIC display "SC"?
  
  Yes
  - Go To 3
  No
  - Trailer wiring/brakes are shorted to ground, refer the customer to an authorized trailer dealer.
(B402) TRAILER TOW BRAKE SWITCH DECREASE CIRCUIT SHORTED TO VOLTAGE
1. Turn ignition off.
2. Disconnect the ITBM C3 harness connector.
3. Disconnect the ITBM Switch harness connector.
4. Check connectors - Clean/repair as necessary.
5. Measure the voltage between the (B402) Trailer Tow Brake Switch Decrease circuit and ground.
  Is there any voltage present?
  
  Yes
  - Repair the (B402) Trailer Tow Brake Switch Decrease circuit for a short to voltage.
  - Perform the ITBM VERIFICATION TEST. Refer to STANDARD PROCEDURE .
  No
  - Go To 4
(B407) TRAILER TOW BRAKE SWITCH INCREASE CIRCUIT SHORTED TO VOLTAGE
1. Measure the voltage between the (B407) Trailer Tow Brake Switch Increase circuit and ground.
  Is there any voltage present?
  
  Yes
  - Repair the (B407) Trailer Tow Brake Switch Increase circuit for a short to voltage.
  - Perform the ITBM VERIFICATION TEST. Refer to STANDARD PROCEDURE .
  No
  - Go To 5
INTEGRATED TRAILER BRAKE MODULE (ITBM)
1. Using the wiring diagrams as a guide, check all related splices and connectors for signs of water intrusion, corrosion, pushed out or bent terminals, and correct pin tension. Pay particular attention to all Power and Ground circuits.
  Were there any problems found?
  
  Yes
  - Repair as necessary.
  - Perform the ITBM VERIFICATION TEST. Refer to STANDARD PROCEDURE .
  No
  - Replace the Integrated Trailer Brake Module (ITBM) in accordance with Service Information. Refer to MODULE, INTEGRATED TRAILER BRAKE (ITBM), REMOVAL .
INTERMITTENT WIRING AND CONNECTORS
1. The conditions necessary to set this DTC are not present at this time.
2. Using the wiring diagrams as a guide, check all related splices and connectors for signs of water intrusion, corrosion, pushed out or bent terminals, and correct pin tension.
3. Wiggle test the wiring harness and connectors while monitoring the scan tool data relative to this circuit.
4. Look for the data to change or for the DTC to reset during the wiggle test.
5. While monitoring the scan tool data relative to this circuit.
6. Connect the trailer to the vehicle.
7. Look for the data to change other than as expected or for the DTC to reset.
  Were any problems found?
  
  Yes
  - Repair as necessary. Possible trailer wiring problem, refer the customer to an authorized trailer dealer.
  - Perform the ITBM VERIFICATION TEST. Refer to STANDARD PROCEDURE .
  No
  - Test complete, the condition or conditions that originally set this DTC are not present at this time.