Possible Sources
WARNING: This page is about a different car, the 2018 Lincoln Navigator. However, it is still accessible from the selected car via links, so may be relevant.
- Wiring, terminals or connectors
- Vacuum pump relay
- ABS module
Harness Side
| Circuit | Pin |
Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may cause damage to the connector.
- VA1: CHECK FOR BRAKE BOOSTER VACUUM SENSOR DTCS
- Ignition ON, engine OFF.
- Carry out the ABS self-test.
- Is DTC C101A:15, C101A16 or C101A29 present in the ABS module?
Yes No DIAGNOSE all vacuum sensor DTCs before diagnosing any vacuum pump DTCs.
GO to PINPOINT TEST CA .If no DTCs are present or if only DTC C101C:67 is present, Go to VA2.
If DTC C101C:14 is present, Go to VA4.
For all others,
No fault found.
REFER to the ABS Module DTC Chart. - VA2: CHECK THE BRAKE BOOSTER AND VACUUM HOSES FOR LEAKS
- Ignition OFF.
- Verify all the vacuum hoses are connected to their respective ports.
- Inspect the following items for leaks:
- brake booster-to-vacuum pump hose
- brake booster vacuum hose elbow seal
- brake booster vacuum sensor seal
- brake booster-to-master cylinder seal
- brake booster body
- Are any leaks found?
Yes No REPAIR or INSTALL new components as necessary.
CYCLE the ignition and CARRY OUT the ABS module self-test to clear the DTC.INSPECT the vacuum pump relay socket for corrosion, pushed-out terminals or bent pins. REPAIR or INSTALL new as necessary.
If the relay socket is OK, INSTALL a new vacuum pump relay.
CYCLE the ignition and CARRY OUT the ABS module self-test to clear the DTC. - VA3: ISOLATE THE VACUUM PUMP RELAY
- Remove the vacuum pump relay.
- Ignition ON, engine OFF.
- Does the vacuum pump run continuously?
Yes No REPAIR the brake vacuum pump control circuit for a short to voltage.
CYCLE the ignition and CARRY OUT the ABS module self-test to clear the DTC.INSPECT the vacuum pump relay socket for corrosion, pushed-out terminals or bent pins. REPAIR or INSTALL new as necessary.
If the relay socket is OK, INSTALL a new vacuum pump relay.
CYCLE the ignition and CARRY OUT the ABS module self-test to clear the DTC. - VA4: CHECK THE VACUUM PUMP RELAY CONTROL CIRCUIT FOR A SHORT TO VOLTAGE
- Ignition OFF.
- ABS Module connector disconnected. (C135)
- Remove the vacuum pump relay.
- Ignition ON, engine OFF.
- Measure the voltage between:
(+) Vacuum Pump Relay Connector, Harness Side (-) VPRC Ground - Is any voltage present?
Yes No REPAIR the circuit.
CYCLE the ignition and CARRY OUT the ABS module self-test to clear the DTC.Go to VA5. - VA5: CHECK FOR CORRECT ABS MODULE OPERATION
- ABS Module connector disconnected. (C135) (if not previously disconnected)
- Using a good light source, inspect all disconnected electrical connectors for the following:
- corrosion - install new connector or terminal and clean the module pins
- damaged or bent pins - install new terminals or pins
- pushed-out pins - install new pins as necessary
- spread terminals - install new terminals as necessary
- Install the brake vacuum pump relay. Make sure the relay is fully seated.
- ABS Module connector connected. (C135) Make sure the connector seats and latches correctly.
- Operate the system and determine if the concern is still present.
- Is the concern still present?
Yes No INSTALL a new ABS module.
CHECK OASIS for any applicable TSBs.
If a TSB exists for this concern, DISCONTINUE this test and FOLLOW the TSB instructions.
If no TSBs address this concern, INSTALL a new ABS module. REFER to Anti-Lock Brake System (ABS) Module .
ORDER a replacement ABS module and INCLUDE the RVC on the form.
If this is a Ford paid repair, INCLUDE the RVC on the warranty claim form.
When complete, SELECT the "X" in the top right corner to CLOSE this procedure and RETURN to the PTS web site.The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector. ADDRESS the root cause of any connector or pin issues.