Diagnostic Test

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

VERIFY THE DTC IS ACTIVE
NOTE:
This DTC must be active for the results of this test to be valid.
1. Turn the ignition on.
2. With the scan tool, read and record DTCs.
3. With the scan tool, read and record Freeze Fame information.
4. With the scan tool, erase DTCs.
5. Start the engine.
6. Press the brake pedal firmly and release.
7. With the scan tool, read and record DTCs.
  Is the DTC active at this time?
  
  Yes
  - Go To 2
  No
  - Perform the ABS INTERMITTENT CONDITION TEST. Refer to ABS INTERMITTENT CONDITION .
MECHANICAL BRAKE SYSTEM INSPECTION
1. Turn the ignition off.
2. Check the brake fluid for contaminants.
3. Visually inspect the brake lines between the Brake Master Cylinder and the Integrated Control Unit (ICU) for bent, damaged, or pinched restrictions.
  Where any problems found?
  
  Yes
  - Repair as necessary.
  - Perform the ABS VERIFICATION TEST. Refer to ABS VERIFICATION TEST .
  No
  - Go To 3
BRAKE FLUID PRESSURE
1. Start the engine.
2. The brake pedal released.
3. With the scan tool, under "Data Display" read the Brake Fluid Pressure.
  Is the Brake Fluid Pressure below 10 bar (145 psi)?
  
  Yes
  - Go To 4
  No
  - Go To 5
BRAKE PEDAL INSPECTION
1. Turn the ignition off.
2. Check the brake pedal for damage or restrictions not allowing it to fully return.
  Where any problems found?
  
  Yes
  - Repair as necessary.
  - Perform the ABS VERIFICATION TEST. Refer to ABS VERIFICATION TEST .
  No
  - Replace the Integrated Control Unit (ICU) in accordance with the Service Information. Refer to INTEGRATED CONTROL UNIT (ICU), REMOVAL .
  - Perform the ABS VERIFICATION TEST. Refer to ABS VERIFICATION TEST .
STOP LAMP SWITCH
1. Start the engine.
2. With the scan tool, under "Data Display" monitor the Stop Lamp Switch and the Brake Fluid Pressure.
3. Press the brake pedal slowly.
  Did the Stop Lamp Switch indicate pressed before their was Brake Fluid Pressure?
  
  Yes
  - Go To 6
  No
  - Replace the Stop Lamp Switch in accordance with the Service Information. Refer to SWITCH, STOP LAMP, REMOVAL .
  - Perform the ABS VERIFICATION TEST. Refer to ABS VERIFICATION TEST .
INTEGRATED CONTROL UNIT (ICU)
1. Turn the ignition off.
2. Disconnect the Primary brake line between the master cylinder and the Integrated Control Unit (ICU).
3. Turn the ignition on.
4. With the scan tool, under "Data Display" read the Brake Fluid Pressure.
  Is the Brake Fluid Pressure below 10 bar (145 psi)?
  
  Yes
  - Replace the Brake Master Cylinder in accordance with the Service Information. Refer to MASTER CYLINDER, BRAKE, REMOVAL .
  - Perform the ABS VERIFICATION TEST. Refer to ABS VERIFICATION TEST .
  No
  - Replace the Integrated Control Unit (ICU) in accordance with the Service Information. Refer to INTEGRATED CONTROL UNIT (ICU), REMOVAL .
  - Perform the ABS VERIFICATION TEST. Refer to ABS VERIFICATION TEST .