LEMON Manuals: Even more car manuals for everyone
Home >> Ford >> 2012 >> Mustang Base, 2D Coupe, Automatic Trans >> Repair and Diagnosis >> External Pages >> Different car >> Section 355 (Anti-Lock Brake System & Stability Control) >> Diagnosis And Testing >> Anti-Lock Control - Four-Channel >> Pinpoint Tests >> Pinpoint Test AJ: Vacuum Pressure Sensor DTCs >> PINPOINT TEST AJ: VACUUM PRESSURE SENSOR DTCs

PINPOINT TEST AJ: VACUUM PRESSURE SENSOR DTCs

WARNING: This page is about a different car, the 2013 Ford F-550 Super Duty, 2013 Ford F-450 Super Duty, 2013 Ford F-350 Super Duty, and 2013 Ford F-250 Super Duty. However, it is still accessible from the selected car via links, so may be relevant.
  1. AJ1 CHECK THE BRAKE BOOSTER AND VACUUM HOSES FOR LEAKS 
    • Inspect the vacuum hoses, brake booster and brake booster seals for leaks or evidence of leaks.
    • Are any leaks or evidence of leaks found? 
    1. Yes  : REPAIR or INSTALL new components as necessary.
    2. No  : GO to AJ2.
  2. AJ2 CHECK THE ABS MODULE OUTPUT 
    • Ignition OFF.
    • Disconnect: Brake Booster Vacuum Sensor C149.
    • Measure the voltage between the brake booster vacuum sensor C149, harness side and ground as follows:
      ABS Module Circuit
      C149-3 LCA16 (GN)
      C149-2 RCA16 (BU/BN)
      Fig 1: Measuring Voltage Between Brake Booster Vacuum Sensor C149, Harness Side And Ground
      G08596614Courtesy of FORD MOTOR CO.
    • Is the voltage equal to or greater than 4.8 volts? 
    1. Yes  : GO to AJ3.
    2. No  : REPAIR the circuit. CLEAR the DTC. REPEAT the self-test. If the DTC returns, GO to  AJ7.
  3. AJ3 CHECK THE VACUUM SENSOR WIRING FOR A SHORT TO VOLTAGE 
    • Ignition OFF.
    • Disconnect: ABS Module C135.
    • Ignition ON.
    • Measure the voltage between the brake booster vacuum sensor C149, harness side and ground as follows:
      ABS Module Circuit
      C149-1 VCA16 (YE/BU)
      C149-2 RCA16 (BU/BN)
      C149-3 LCA16 (GN)
      Fig 2: Measuring Voltage Between Brake Booster Vacuum Sensor C149, Harness Side And Ground
      G08596615Courtesy of FORD MOTOR CO.
    • Is any voltage present? 
    1. Yes  : REPAIR the circuit. CLEAR the DTC. REPEAT the self-test. If the DTC returns, GO to  AJ7.
    2. No  : GO to AJ4.
  4. AJ4 CHECK THE VACUUM SENSOR WIRING FOR A SHORT TO GROUND 
    • Ignition OFF.
    • Measure the resistance between the brake booster vacuum sensor C149, harness side and ground as follows:
      ABS Module Circuit
      C149-1 VCA16 (YE/BU)
      C149-2 RCA16 (BU/BN)
      C149-3 LCA16 (GN)
      Fig 3: Measuring Resistance Between Brake Booster Vacuum Sensor C149, Harness Side And Ground
      G08596616Courtesy of FORD MOTOR CO.
    • Are the resistances greater than 10, 000 ohms? 
    1. Yes  : GO to AJ5.
    2. No  : REPAIR the circuit. CLEAR the DTC. REPEAT the self-test. If the DTC returns, GO to  AJ7.
  5. AJ5 CHECK THE VACUUM SENSOR WIRING FOR AN OPEN 
    • Measure the resistance between the brake booster vacuum sensor C149, harness side and the ABS module C135, harness side as follows:
      Brake Booster Vacuum Sensor Circuit ABS Module
      C149-1 VCA16 (YE/BU) C135-33
      C149-2 RCA16 (BU/BN) C135-34
      C149-3 LCA16 (GN) C135-29
      Fig 4: Measuring Resistance Between Brake Booster Vacuum Sensor C149, Harness Side And ABS Module C135
      G08596617Courtesy of FORD MOTOR CO.
    • Are the resistances less than 3 ohms? 
    1. Yes  : GO to AJ6.
    2. No  : REPAIR the circuit. CLEAR the DTC. REPEAT the self-test. If the DTC returns, GO to  AJ7.
  6. AJ6 CHECK THE VACUUM SENSOR WIRING FOR A SHORT TOGETHER 
    • Measure the resistance between the brake booster vacuum sensor C149 pins, harness side as follows:
      Brake Booster Vacuum Sensor Circuit Brake Booster Vacuum Sensor
      C149-1 VCA16 (YE/BU)/RCA16 (BU/BN) C149-2
      C149-1 VCA16 (YE/BU)/LCA16 (GN) C149-3
      C149-2 RCA16 (BU/BN)/LCA16 (GN) C149-3
      Fig 5: Measuring Resistance Between Brake Booster Vacuum Sensor C149 Pins
      G08596618Courtesy of FORD MOTOR CO.
    • Are the resistances greater than 10, 000 ohms? 
    1. Yes  : INSTALL a new brake booster vacuum sensor. REFER to POWER BRAKE ACTUATION .

      DRIVE the vehicle at speeds greater than 10 km/h (6 mph) for at least 4 minutes and carry out at lest 3 stops.

      CARRY OUT the ABS module self-test. If DTC C101A:12, C101A:14, C101A:1C or C101A:2F returns, GO to AJ7. If DTC C101A:65 or C101A:67 returns, INSTALL a new brake booster vacuum sensor.

    2. No  : REPAIR the circuit. CLEAR the DTC. REPEAT the self-test. If the DTC returns, GO to AJ7.
  7. AJ7 CHECK FOR CORRECT ABS MODULE OPERATION 
    • Ignition OFF.
    • Disconnect and inspect the ABS module electrical connector.
    • Repair:
      • corrosion (install new connector or terminal - clean module pins)
      • damaged or bent pins - install new terminals/pins
      • pushed-out pins - install new pins as necessary
    • Connect the ABS module electrical connector, make sure it seats and latches correctly.
    • Connect the brake booster vacuum sensor electrical connector, make sure it seats and latches correctly.
    • Operate the system and determine if the concern is still present.
    • Is the concern is still present? 
    1. 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. REFER to ANTI-LOCK BRAKE SYSTEM (ABS) MODULE .

    2. 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.
scientia non olet · About LEMON Manuals