Visual Inspection And Diagnostic Pre-Checks

• Make sure BJB fuse 22 (40A) and the fuse socket are OK.

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: DETERMINE VACUUM PUMP SYMPTOM 
   • Ignition ON, engine running.
   • Allow the engine to run for at least 3 minutes to draw a vacuum in the brake booster.
   • Press and release the brake pedal at least 3 times to deplete the vacuum in the brake booster.
   • Listen to the vacuum pump and determine if it is running constantly or not running at all.
   • Is the vacuum pump running constantly? 

   Yes	No
   GO to PINPOINT TEST V.	Go to  U2.

2. U2: 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  U3.

3. U3: 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  U4.

4. U4: CHECK FOR DTC P258A:14 
   • Review the results from the ABS module self-test.
   • Is DTC P258A:14 present? 

   Yes	No
   Go to  U6.	Go to  U5.

5. U5: 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  U6.

6. U6: CHECK THE BRAKE VACUUM PUMP RELAY CONTROL CIRCUIT FOR AN OPEN 
   • Ignition OFF.
   • ABS Module connector disconnected.
   • Measure the resistance between:

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

   • 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 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  U8.	REPAIR the circuit.

8. U8: 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  U9.	REPAIR the circuit.

9. U9: 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  U10.	VERIFY the ground eyelet is clean and securely fastened. REFER to the Grounds wiring diagrams for ground information. CLEAN or TIGHTEN as necessary. If the ground eyelet is OK, REPAIR the circuit.

10. U10: CHECK THE BRAKE VACUUM PUMP RELAY SWITCHED VOLTAGE SUPPLY CIRCUIT FOR AN OPEN 
    • Measure the voltage between:

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

    • Is the voltage greater than 11 volts? 

    Yes	No
    Go to  U11.	REPAIR the circuit.

11. U11: 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  U12.	REPAIR the circuit.

12. U12: 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  U13.	INSTALL a new brake vacuum pump. REFER to the Removal and Installation procedure in the Anti-Lock Brake System (ABS) and Stability Control article.

13. U13: CHECK FOR CORRECT ABS MODULE OPERATION 
    • Ignition OFF.
    • ABS Module connector 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
    • ABS Module connector connected. 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 article. 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.

    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.