Pinpoint Test H : C109D, C109E, C109F

WARNING: This page is about a different car, the 2017 Lincoln Navigator and 2017 Ford Expedition. However, it is still accessible from the selected car via links, so may be relevant.

NOTE: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may damage the connector.

H1 CHECK THE ABS MODULE DTCs

Ignition ON.

Using a diagnostic scan tool, carry out the ABS module self-test.

Is DTC C109D the only DTC present?

Yes	GO to H2.
No	If DTC C109E or C109F was retrieved, GO to H6.For all other DTCs, GO to the DTC Chart: ABS Module .

H2 CHECK DTC RETURNABILITY

Using a diagnostic scan tool, clear the ABS module DTCs.

Ignition OFF.

Start the engine.

NOTE: It may take up to 3 minutes for DTC C109D to set.

Allow the vehicle to idle for a minimum of 4 minutes. Apply and release the brake pedal a minimum of 3 times per minute with normal pedal force for up to 3 minutes.

Ignition OFF.

Ignition ON.

Using a diagnostic scan tool, carry out the ABS module self-test.

Is DTC C109D the only DTC present?

Yes	GO to H3.
No	If DTC C109E or C109F was retrieved, GO to H6.For all other DTCs, GO to the DTC Chart: ABS Module . If no DTCs are set, the system is operating correctly as this time. The concern may have been caused by a loose or corroded connector.

H3 CHECK THE ENGINE VACUUM

Carry out the Intake Manifold Vacuum Test, refer to Diagnosis and Testing in Engine System General Information .

Record the vacuum reading.

Does the vacuum gauge indicate normal vacuum?

Yes	GO to H4.
No	FOLLOW the diagnostic procedure in Engine System General Information .

H4 CHECK THE BRAKE BOOSTER

Carry out the Brake Booster Component Test. Refer to Brake System General Information .

Do the brake booster and check valve pass the component test?

Yes	GO to H5.
No	REPAIR or INSTALL new as necessary. REFER to Power Brake Actuation .

H5 CHECK THE BRAKE BOOSTER VACUUM LEVEL (BBVACLVL) PID

Using a diagnostic scan tool, view the BBVACLVL PID.

Compare the PID display to the vacuum reading recorded in Step H3.

Does the PID match the recorded vacuum reading of ±3.386 kPa (1 in-Hg)?

Yes	REPAIR any vacuum leaks in the vacuum system. For 4x4 vehicles, REPAIR any vacuum leaks from the vacuum hub lock system.
No	INSTALL a new brake booster vacuum sensor. REFER to Power Brake Actuation .

H6 CHECK THE BRAKE BOOSTER VACUUM SENSOR

Inspect the vacuum sensor ambient air pressure inlet ports.

Are the ports free of contamination, debris and foreign material?

Yes	GO to H7.
No	REPAIR or INSTALL a new vacuum sensor as necessary. REFER to Power Brake Actuation .

H7 CHECK THE BRAKE BOOSTER VACUUM SENSOR CIRCUITS FOR A SHORT TO GROUND

Ignition OFF.

Disconnect ABS module C135 .

Disconnect brake booster vacuum sensor C149 .

Measure:

Positive Lead	Measurement / Action	Negative Lead
C149-1	Courtesy of FORD MOTOR COMPANY	Ground
C149-2	Courtesy of FORD MOTOR COMPANY	Ground
C149-3	Courtesy of FORD MOTOR COMPANY	Ground

Are the resistances greater than 10, 000 ohms?

Yes	GO to H8.
No	REPAIR the circuit.

H8 CHECK THE BRAKE BOOSTER VACUUM SENSOR CIRCUITS FOR AN OPEN

Measure:

Positive Lead	Measurement / Action	Negative Lead
C149-1	Courtesy of FORD MOTOR COMPANY	C135-10
C149-2	Courtesy of FORD MOTOR COMPANY	C135-28
C149-3	Courtesy of FORD MOTOR COMPANY	C135-2

Are the resistances less than 3 ohms?

Yes	GO to H9.
No	REPAIR the circuit.

H9 CHECK THE BRAKE BOOSTER VACUUM SENSOR CIRCUITS FOR A SHORT TOGETHER

Measure:

Positive Lead	Measurement / Action	Negative Lead
C149-1	Courtesy of FORD MOTOR COMPANY	C149-2
C149-1	Courtesy of FORD MOTOR COMPANY	C149-3
C149-2	Courtesy of FORD MOTOR COMPANY	C149-3

Are the resistances greater than 10, 000 ohms?

Yes	GO to H10.
No	REPAIR the circuit.

H10 CHECK THE ACTIVE BRAKE BOOSTER VACUUM SENSOR CIRCUITS FOR A SHORT TO VOLTAGE

Ignition ON.

Measure:

Positive Lead	Measurement / Action	Negative Lead
C149-1	Courtesy of FORD MOTOR COMPANY	Ground
C149-2	Courtesy of FORD MOTOR COMPANY	Ground
C149-3	Courtesy of FORD MOTOR COMPANY	Ground

Is any voltage present?

Yes	REPAIR the circuit.
No	GO to H11.

H11 CHECK THE BRAKE BOOSTER VACUUM SENSOR CONNECTOR

Ignition OFF.

Inspect brake booster vacuum sensor connector for:
- corrosion
- damaged pins
- pushed-out pins

Connect ABS module C135 . Make sure it seats and latches correctly.

Connect brake booster vacuum sensor C149 . Make sure it seats and latches correctly.

Operate the system and verify the concern is still present.

Is the concern still present?

Yes	INSTALL a new vacuum sensor. REFER to Power Brake Actuation . CLEAR the DTCs. REPEAT the self-test. If DTC C109E or C109F returns, GO to H12.
No	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.

H12 CHECK FOR CORRECT ABS MODULE OPERATION

Ignition OFF.

Disconnect and inspect ABS module C135 (if not previously disconnected).

Repair:
- corrosion (install new connector or terminal - clean module pins)
- damaged or bent pins - install new terminals or pins
- pushed-out pins - install new pins as necessary

Connect ABS module C135 . Make sure it seats and latches correctly.

Connect brake booster vacuum sensor C149 . Make sure it seats and latches correctly.

Operate the system and determine if the concern is still present.

Is the concern still present?

Yes	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. Anti-Lock Brake System (ABS) Module .
No	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.