PINPOINT TEST I: DTCs C109D, C109E AND C109F

WARNING: This page is about a different car, the 2014 Ford F-150. 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.

I1 CHECK THE ABS MODULE DTCs
- Review the DTCs recorded during Inspection and Verification.
Was DTC C109D the only recorded DTC?
- Yes : GO to I2 .
- No : If DTC C109E and/or C109F was retrieved, GO to I6.
  For all other DTCs, REFER to the ABS MODULE DTC CHART .
I2 CHECK DTC RETURNABILITY
- Using the scan tool, clear the ABS module DTCs.
- Ignition OFF.
- Disconnect the scan tool.
- 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 for a minimum of 3 times per minute with normal pedal force for up to 3 minutes
- Ignition OFF.
- Connect the scan tool.
- Ignition ON.
- Enter the following diagnostic mode on the scan tool: Self Test - ABS Module.
Is DTC C109D the only vacuum sensor DTC present?
- Yes : GO to I3 .
- No : If DTC C109E and/or C109F was retrieved, GO to I6.
  For all other DTCs, REFER to the ABS MODULE DTC CHART .
  
  If no DTC is set, the system is operating correctly as this time. The concern may have been caused by a loose or corroded connector. CLEAR the DTC. REPEAT the self-test.
I3 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 I4 .
- No : FOLLOW the diagnostic procedure in ENGINE SYSTEM - GENERAL INFORMATION .
I4 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 I5 .
- No : REPAIR or INSTALL new as necessary. CLEAR the DTC. REPEAT the self-test.
I5 CHECK THE BRAKE BOOSTER VACUUM LEVEL (BBVACLVL) PID
- Connect the scan tool.
- Start the engine.
- Enter the following diagnostic mode on the scan tool: Data Logger - ABS Module.
- Compare the recorded vacuum reading the brake booster vacuum level PID.
Does the PID match the recorded vacuum reading of ±3.386 kPa (1 in-Hg)?
- Yes : REPAIR any vacuum leaks at the vacuum system. For 4x4 vehicles, REPAIR any vacuum leaks from the vacuum hub lock system. REPEAT the ABS module self-test.
- No : INSTALL a new brake booster vacuum sensor. REFER to POWER BRAKE ACTUATION . CLEAR the DTCs. TEST the system for normal operation.
I6 CHECK THE BRAKE BOOSTER VACUUM SENSOR
- Inspect the vacuum sensor ambient air pressure inlet ports.
Are both ports free of contamination, debris and/or foreign material?
- Yes : GO to I7 .
- No : REPAIR or INSTALL a new vacuum sensor as necessary. REFER to POWER BRAKE ACTUATION . CLEAR the DTCs. REPEAT the self-test.
I7 CHECK THE BRAKE BOOSTER VACUUM SENSOR CIRCUITS FOR A SHORT TO GROUND
- Disconnect: ABS Module C135 .
- Disconnect: Brake Booster Vacuum Sensor C149 .
- Measure the resistance between ground and:
  - brake booster vacuum sensor C149-1 , circuit VCA22 (GN/BN), harness side.
  - brake booster vacuum sensor C149-2 , circuit GD120 (BK/GN), harness side.
  - brake booster vacuum sensor C149-3 , circuit CCA22 (GY/YE), harness side.
    
    Fig 1: Checking Brake Booster Vacuum Sensor Circuits For Short To Ground
    Courtesy of FORD MOTOR CO.
Is the resistance greater than 10, 000 ohms?
- Yes : GO to I8 .
- No : REPAIR the affected circuit(s). CLEAR the DTCs. REPEAT the self-test.

I8 CHECK THE BRAKE BOOSTER VACUUM SENSOR CIRCUITS FOR AN OPEN

Measure the resistance between the ABS module C135 , harness side and the brake booster vacuum sensor C149 , harness side as follows:

ABS Module	Circuit	Vacuum Sensor
C135-10	VCA22 (GN/BN)	C149-1
C135-28	GD120 (BK/GN)	C149-2
C135-2	CCA22 (GY/YE)	C149-3

Fig 2: Measuring Resistance Between ABS Module C135 And Brake Booster Vacuum Sensor C149, Harness Side

Courtesy of FORD MOTOR CO.

Are the resistances less than 5 ohms?

Yes : GO to I9 .
No : REPAIR the affected circuit(s). CLEAR the DTCs. REPEAT the self-test.

I9 CHECK THE BRAKE BOOSTER VACUUM SENSOR CIRCUITS FOR A SHORT TOGETHER
- Measure the resistance between:
  - brake booster vacuum sensor C149-1 , circuit VCA22 (GN/BN), harness side and brake booster vacuum sensor C149-2 , circuit GD120 (BK/GN), harness side.
  - brake booster vacuum sensor C149-1 , circuit VCA22 (GN/BN), harness side and brake booster vacuum sensor C149-3 , circuit CCA22 (GY/YE), harness side.
  - brake booster vacuum sensor C149-2 , circuit GD120 (BK/GN), harness side, and brake booster vacuum sensor C149-3 , circuit CCA22 (GY/YE), harness side.
    
    Fig 3: Checking Brake Booster Vacuum Sensor Circuits For Short Together
    Courtesy of FORD MOTOR CO.
Are the resistances greater than 10, 000 ohms?
- Yes : GO to I10 .
- No : REPAIR the affected circuit(s). CLEAR the DTCs. REPEAT the self-test.
I10 CHECK THE ACTIVE BRAKE BOOSTER VACUUM SENSOR CIRCUITS FOR A SHORT TO VOLTAGE
- Ignition ON.
- Measure the voltage between ground and:
  - brake booster vacuum sensor C149-1 , circuit VCA22 (GN/BN), harness side.
  - brake booster vacuum sensor C149-2 , circuit GD120 (BK/GN), harness side.
  - brake booster vacuum sensor C149-3 , circuit CCA22 (GY/YE), harness side.
    
    Fig 4: Checking Active Brake Booster Circuits For Short To Voltage
    Courtesy of FORD MOTOR CO.
Is any voltage present?
- Yes : REPAIR the affected circuit(s). CLEAR the DTCs. REPEAT the self-test.
- No : GO to I11 .
I11 CHECK THE BRAKE BOOSTER VACUUM SENSOR CONNECTOR
- Ignition OFF.
- Check brake booster vacuum sensor connector for:
  - corrosion
  - damaged pins
  - pushed-out pins
- Connect: Brake Booster Vacuum Sensor C149 .
- Make sure the connector seats correctly, then 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 return, GO to I12 .
- No : The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector. CLEAR the DTCs. REPEAT the self-test.
I12 CHECK THE ABS MODULE CONNECTORS
- Ignition OFF.
- Disconnect: ABS Module C135 .
- Check ABS module connector for:
  - corrosion
  - damaged pins
  - pushed-out pins
- Connect: ABS Module C135 .
- Make sure the connector seats correctly, then operate the system and verify the concern is still present.
Is the concern still present?
- Yes : INSTALL a new ABS module. REFER to ANTI-LOCK BRAKE SYSTEM (ABS) MODULE . TEST the system for normal operation.
- No : The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector. CLEAR the DTCs. REPEAT the self-test.