Possible Causes
WARNING: This page does not describe the selected car, but rather 9 other vehicles, including the 2021 Lincoln Corsair, 2021 Ford Transit-350 HD, 2021 Ford Transit-350, 2021 Ford Transit-250, and 2021 Ford Transit-150. However, it is still accessible from the selected car via links, so may be relevant.
- Air trapped in the hydraulic system
- External brake system leak
- Internal EBB unit leak
- EBB unit internal failure
- CO1: INSPECT THE BRAKE SYSTEM FOR LEAKS
- With the transmission in NEUTRAL, position the vehicle on a hoist. For additional information, refer to Jacking and Lifting article.
- Thoroughly inspect the following brake components for any signs of leaks:
- brake tubes
- brake hoses
- brake calipers
- brake fluid reservoir
- EBB unit
- Are any components found to be leaking?
Yes No REPAIR any leaks or INSTALL new components as necessary. Go to CO2. - CO2: RECHECK THE ABS MODULE DTCS
- Ignition ON, engine OFF.
- Clear the ABS DTCs.
- Put the ABS module in sleep mode by performing the following steps:
- With ALL doors closed, set the ignition from ON to OFF.
- Disconnect the diagnostic scan tool.
- Open the door, exit the vehicle and close the door.
- Wait a minimum of 90 seconds for the ABS module to enter sleep mode.
- Ignition ON, engine OFF.
- Wait at least 30 seconds without pressing the brake pedal.
- Apply and release the brake pedal 10 times in the following manner:
- Fully apply the brake pedal with firm pressure, as if coming to a sudden stop.
- Hold the brake pedal with the same force for 5 seconds.
- Fully release the brake pedal for 10 seconds.
- Repeat the above 3 steps 10 times.
- Put the ABS module in sleep mode by performing the following steps:
- With ALL doors closed, set the ignition from ON to OFF.
- Disconnect the diagnostic scan tool.
- Open the door, exit the vehicle and close the door.
- Wait a minimum of 90 seconds for the ABS module to enter sleep mode.
- Ignition ON, engine OFF. Carry out the ABS self-test.
- Are any of the DTCs listed in the Fault Trigger Conditions Table present?
Yes No Go to CO3. The condition required to set the DTC is not present at this time and may be an intermittent condition. - CO3: BLEED THE BRAKE SYSTEM AND CHECK FOR LEAKS
- Bleed the brake system. Refer to the Brake System Pressure Bleeding general procedure in the Brake System General Information article.
- Using a diagnostic scan tool, carry out the Bleed Check routine.
- Does the EBB unit pass the bleed routine?
Yes No Go to CO6. Go to CO4. - CO4: BLEED THE BRAKE SYSTEM AND CHECK FOR LEAKS
- Bleed the brake system. Refer to the Brake System Pressure Bleeding general procedure in the Brake System General Information article.
- Using a diagnostic scan tool, carry out the Bleed Check routine.
- Does the EBB unit pass the bleed routine?
Yes No Go to CO6. Go to CO5. - CO5: BLEED THE BRAKE SYSTEM AND CHECK FOR LEAKS
- Bleed the brake system. Refer to the Brake System Pressure Bleeding general procedure in the Brake System General Information article.
- Using a diagnostic scan tool, carry out the Bleed Check routine.
- Does the EBB unit pass the bleed routine?
Yes No Go to CO6. The HCU and ABS module are a single assembly known as the EBB unit.
CHECK OASIS for any service articles: TSB, GSB, SSM or FSA.
If a service article exists for this concern, DISCONTINUE this test and FOLLOW the service article instructions.
If no service articles address this concern, INSTALL a new EBB unit. REFER to Anti-Lock Brake System (ABS) and Stability Control article. - CO6: RECHECK THE ABS MODULE DTCS
- Put the ABS module in sleep mode by performing the following steps:
- With ALL doors closed, set the ignition from ON to OFF.
- Disconnect the diagnostic scan tool.
- Open the door, exit the vehicle and close the door.
- Wait a minimum of 90 seconds for the ABS module to enter sleep mode.
- Ignition ON, engine OFF.
- Wait at least 30 seconds without pressing the brake pedal.
- Apply and release the brake pedal 10 times in the following manner:
- Fully apply the brake pedal with firm pressure, as if coming to a sudden stop.
- Hold the brake pedal with the same force for 5 seconds.
- Fully release the brake pedal for 10 seconds.
- Repeat the above 3 steps 10 times.
- Put the ABS module in sleep mode by performing the following steps:
- With ALL doors closed, set the ignition from ON to OFF.
- Disconnect the diagnostic scan tool.
- Open the door, exit the vehicle and close the door.
- Wait a minimum of 90 seconds for the ABS module to enter sleep mode.
- Ignition ON, engine OFF.
Carry out the ABS self-test.
- Are any of the DTCs listed in the Fault Trigger Conditions Table present?
Yes No Go to CO7. The repair is complete. The DTC was most likely set due to air trapped in the brake fluid system. - Put the ABS module in sleep mode by performing the following steps:
- CO7: INSPECT THE BRAKE SYSTEM FOR LEAKS
- With the transmission in NEUTRAL, position the vehicle on a hoist. For additional information, refer to Jacking and Lifting article.
- Thoroughly inspect the following brake components for any signs of leaks:
- brake tubes
- brake hoses
- brake calipers
- brake fluid reservoir
- EBB unit
- Are any components found to be leaking?
Yes No REPAIR any leaks or INSTALL new components as necessary. The HCU and ABS module are a single assembly known as the EBB unit.
CHECK OASIS for any service articles: TSB, GSB, SSM or FSA.
If a service article exists for this concern, DISCONTINUE this test and FOLLOW the service article instructions.
If no service articles address this concern, INSTALL a new EBB unit. REFER to Anti-Lock Brake System (ABS) and Stability Control article.