Possible Causes

• Wiring, terminals or connectors
• Brake booster vacuum sensor
• Brake vacuum pump relay
• Brake vacuum pump
• ABS module

Visual Inspection and Diagnostic Pre-checks 

• Make sure BJB fuse 22 (40A) and the fuse socket are OK.
  Fig 1: Antilock Braking System (ABS) Module Connector - C135

  Courtesy of FORD MOTOR COMPANY
  CONNECTOR PIN REFERENCE (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.

1. U1: CHECK FOR DTC C0047:16, C0047:1C, C0047:1E OR C0047:64 
   • Ignition ON, engine OFF.
   • Carry out the ABS self-test.
   • Is DTC C0047:16, C0047:1C, C0047:1E or C0047:64 present? 

     Yes	No
     DIAGNOSE these DTCs first. Go to PINPOINT TEST C .	Go to  U2.

2. U2: CHECK THE BRAKE VACUUM PUMP RELAY 
   • Ignition OFF.
   • Remove the brake vacuum pump relay from the BJB.
   • Substitute a known good relay.
   • Apply the brake pedal several times to relieve the vacuum.
     NOTE: Have an assistant listen for the vacuum pump to activate when the ignition is cycled ON.
   • Ignition ON, engine OFF.
   • Does the vacuum pump run when the ignition is cycled ON? 

     Yes	No
     REMOVE the known good relay. INSTALL a new brake vacuum pump relay.	REMOVE the known good relay. Go to  U3.

3. U3: CHECK FOR DTC P258A:14 
   • Review the results from the ABS module self-test.
   • Is DTC P258A:14 present? 

     Yes	No
     Go to  U5.	Go to  U4.

4. U4: CHECK THE BRAKE VACUUM PUMP RELAY CONTROL CIRCUIT FOR A SHORT TO VOLTAGE 
   • Measure the voltage between:

     (+) Vacuum Pump Relay Connector, Harness Side	(-)
     VPRC	Ground

   • Is any voltage present? 

     Yes	No
     REPAIR the circuit.	Go to  U5.

5. U5: CHECK THE BRAKE VACUUM PUMP RELAY CONTROL CIRCUIT FOR AN OPEN 
   • Ignition OFF.
   • ABS Module connector disconnected. (C135)
   • Measure the resistance between:

     (+) Vacuum Pump Relay Connector, Harness Side	(-) ABS Module (C135) Connector, Harness Side
     VPRC	VPRC

   • Is the resistance less than 3 ohms? 

     Yes	No
     Go to  U6.	REPAIR the circuit.

6. U6: CHECK THE BRAKE VACUUM PUMP RELAY OUTPUT CIRCUIT FOR AN OPEN 
   • Vacuum Pump Motor connector disconnected.
   • Measure the resistance between:

     (+) Vacuum Pump Relay Connector, Harness Side	(-) Vacuum Pump Motor Connector, Harness Side
     VPRO	VPRO

   • Is the resistance less than 3 ohms? 

     Yes	No
     Go to  U7.	REPAIR the circuit.

7. U7: CHECK THE BRAKE VACUUM PUMP RELAY OUTPUT CIRCUIT FOR A SHORT TO GROUND 
   • Measure the resistance between:

     (+) Vacuum Pump Motor Connector, Harness Side	(-)
     VPRO	Ground

   • Is the resistance greater than 10, 000 ohms? 

     Yes	No
     Go to  U8.	REPAIR the circuit.

8. U8: CHECK THE BRAKE VACUUM PUMP GROUND CIRCUIT FOR AN OPEN 
   • Measure the resistance between:

     (+) Vacuum Pump Motor Connector, Harness Side	(-)
     GND	Ground

   • Is the resistance less than 3 ohms? 

     Yes	No
     Go to  U9.	VERIFY the ground eyelet is clean and securely fastened. REFER to OEM Ground Distribution (Hybrid/Energi) . If the ground eyelet is OK, REPAIR the circuit.

9. U9: CHECK THE BRAKE VACUUM PUMP RELAY SWITCHED VOLTAGE SUPPLY CIRCUIT FOR AN OPEN 
   • Measure the voltage between:

     (+) Vacuum Pump Relay Relay Connector, Harness Side	(-)
     B+	Ground

   • Is the voltage greater than 11 volts? 

     Yes	No
     Go to  U10.	REPAIR the circuit.

10. U10: CHECK THE BRAKE VACUUM PUMP RELAY COIL VOLTAGE SUPPLY CIRCUIT FOR AN OPEN 
    • Ignition ON, engine OFF.
    • Measure the voltage between:

      (+) Vacuum Pump Relay Connector, Harness Side	(-)
      IGN START/RUN	Ground

    • Is the voltage greater than 11 volts? 

      Yes	No
      Go to  U11.	REPAIR the circuit.

11. U11: CHECK THE BRAKE VACUUM PUMP OPERATION 
    • Ignition OFF.
    • Vacuum Pump Motor connector connected.
      NOTE: It may be necessary to use a higher amperage fuse to activate the vacuum pump.
    • Connect a 5 amp fused jumper wire between the following:

      Point A Vacuum Pump Relay Connector, Component Side	Point B Vacuum Pump Relay Connector, Component Side
      B+	VPRO

    • Remove the fused jumper wire.
    • Does the brake vacuum pump run when the fused jumper wire is connected? 

      Yes	No
      Go to  U12.	INSTALL a new brake vacuum pump. REFER to Anti-Lock Brake System (ABS) And Stability Control (Hybrid/Energi) .

12. U12: CHECK FOR CORRECT ABS MODULE OPERATION 
    • Ignition OFF.
    • ABS Module connector disconnected. (C135)
    • 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
    • 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 service articles: TSB, GSB, SSMs or FSA. If a service article exists for this concern, DISCONTINUE this test and FOLLOW the TSB instructions. If no service articles address this concern, INSTALL a new ABS module. REFER to Anti-Lock Brake System (ABS) And Stability Control (Hybrid/Energi) . 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. 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.