Diagnostic Test

WARNING: This page is about a different car, the 2021 Jeep Grand Cherokee L. However, it is still accessible from the selected car via links, so may be relevant.

READ AND RECORD DTCS AND ENVIRONMENTAL DATA - ERASE DTCS AND CHECK FOR THE DTC TO RETURN
1. With the scan tool, read DTCs in all Electronic Control Units (ECUs) and record on the repair order.
2. For future reference, with the scan tool, run and save a vehicle Scan Report and all related recorded data.
3. With the scan tool, erase all DTCs.
4. Turn the ignition off for a minimum of 10.0 seconds.
5. Turn the ignition on.
6. Using the When Monitored and Set Conditions above and recorded data, operate the vehicle in the conditions that set the DTC.
7. With the scan tool, read DTCs.
Did the DTC return?

Yes
- Go To 2
No
- Perform the BSCM-INTERMITTENT CONDITION TEST. Refer to BSCM INTERMITTENT CONDITION .
CHECK THE MECHANICAL BRAKE PEDAL ASSEMBLY FOR PROPER OPERATION
1. Turn the ignition off.
2. Visually inspect the brake pedal assembly for proper mounting or damage. Refer to PEDAL(S), BRAKE AND/OR ACCELERATOR, REMOVAL AND INSTALLATION .
  Where any problems found?
  
  Yes
  - Repair as necessary.
  - Perform the BSCM VERIFICATION TEST. Refer to BSCM VERIFICATION TEST .
  No
  - Go To 3
CHECK THE BRAKE SYSTEM CONTROL MODULE (BSCM) FOR CORRECT INSTALLATION AND MOUNTING
1. Turn the ignition off.
2. Check the BSCM for damage and mounting with the Electronic Brake Booster.
3. Check the BSCM mounting bolts for a loose or over tightened condition.
4. Verify the correct BSCM part number matches the vehicle.
5. Check all related wiring for bruised, chafed, pierced, or partially broken wires.
6. Check all related connectors for broken, bent, pushed out, or corroded terminals.
  Were any problems found?
  
  Yes
  - Repair as necessary.
  - Perform the BSCM VERIFICATION TEST. Refer to BSCM VERIFICATION TEST .
  No
  - Go To 4
PERFORM THE ABS INITIALIZATION ROUTINE
1. Park the vehicle on level ground.
2. Turn the ignition on.
3. With the scan tool, under "Miscellaneous Functions" perform the ABS Initialization routine.
  Was the ABS Initialization routine successful?
  
  Yes
  - Test complete.
  - Perform the BSCM VERIFICATION TEST. Refer to BSCM VERIFICATION TEST .
  No
  - Perform the ABS Initialization routine again, if still unsuccessful.
  - Go To 5
CHECK RELATED HARNESS CONNECTIONS
1. Turn the ignition off.
2. Disconnect the BSCM harness connector.
3. Disconnect all related in-line harness connections (if equipped).
4. Disconnect the related component harness connectors.
5. Inspect harness connectors, component connectors, and all male and female terminals for the following conditions:
  - Proper connector installation.
  - Damaged connector locks.
  - Corrosion.
  - Other signs of water intrusion.
  - Weather seal damage (if equipped).
  - Bent terminals.
  - Overheating due to a poor connection (terminal may be discolored due to excessive current draw).
  - Terminals that have been pushed back into the connector cavity.
  - Perform a terminal drag test on each connector terminal to verify proper terminal tension.
  Repair any conditions that are found.
6. Connect the BSCM harness connector. Be certain that the harness connector is fully seated and the connector lock is fully engaged.
7. Connect all in-line harness connectors (if equipped). Be certain that all connectors are fully seated and the connector locks are fully engaged.
8. Connect the related component harness connectors. Be certain that all connectors are fully seated and the connector locks are fully engaged.
9. With the scan tool, erase DTCs.
  WARNING:
  To avoid possible serious or fatal injury, check brake capability is available before road testing.
10. Using the recorded Event and Environmental Data, along with the When Monitored and Set Conditions above, operate the vehicle in the conditions that set the DTC.
11. With the scan tool, read BSCM DTCs.
  Did the DTC return?
  
  Yes
  
  NOTE:
  For this failure it is necessary to replace both the ABS Module and the Electronic Brake Booster as a complete unit.
  - Replace the BSCM and the Electronic Brake Booster Unit in accordance with the Service Information. Refer to BOOSTER, ELECTRONIC BRAKE, REMOVAL AND INSTALLATION .
  - Perform the BSCM VERIFICATION TEST. Refer to BSCM VERIFICATION TEST .
  No
  - The wiring or poor connection problem has been repaired.
  - Perform the BSCM VERIFICATION TEST. Refer to BSCM VERIFICATION TEST .