Diagnostic Test

WARNING: This page is about a different car, the 2015 Fiat 500. 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 ABS-INTERMITTENT CONDITION TEST. Refer to ABS INTERMITTENT CONDITION .
CHECK BRAKE PRESSURE SENSOR
1. Start the engine.
2. With the scan tool look at Brake Pressure Sensor Signal and the Brake Switch Signal.
3. With the brakes not applied the Pressure Sensor should read ±15 bar (218 psi).
4. Apply the brakes the Pressure Sensor should read above 15 bar (218 psi).
  Did Brake Pressure Sensor increase above 15 bar (218 psi)?
  
  Yes
  
  NOTE:
  For this failure it is necessary to replace both the ABS Module and the HCU as a complete unit.
  - Replace the Anti-lock Brake System (ABS) Module in accordance with the Service Information. Refer to MODULE, ANTI-LOCK BRAKE SYSTEM, REMOVAL .
  - Replace the Hydraulic Control Unit (HCU) in accordance with the Service Information. Refer to HYDRAULIC CONTROL UNIT (HCU), REMOVAL .
  - Perform the ABS VERIFICATION TEST. Refer to ABS VERIFICATION TEST .
  No
  - Go To 3
CHECK FOR AIR IN BRAKE SYSTEM
NOTE:
Before continuing the brake system must be bled to verify there is no air in the brake system.
1. Turn ignition off.
2. Bleed brake system.
  Was there any air in the brake system?
  
  Yes
  - Repair as needed.
  - Perform ABS VERIFICATION TEST. Refer to ABS VERIFICATION TEST .
  No
  
  NOTE:
  For this failure it is necessary to replace both the ABS Module and the HCU as a complete unit.
  - Replace the Anti-lock Brake System (ABS) Module in accordance with the Service Information. Refer to MODULE, ANTI-LOCK BRAKE SYSTEM, REMOVAL .
  - Replace the Hydraulic Control Unit (HCU) in accordance with the Service Information. Refer to HYDRAULIC CONTROL UNIT (HCU), REMOVAL .
  - Perform the ABS VERIFICATION TEST. Refer to ABS VERIFICATION TEST .