Pinpoint Test T: The Brake Vacuum Pump Is Inoperative

WARNING: This page is about a different car, the 2012 Ford Pickup. However, it is still accessible from the selected car via links, so may be relevant.

T1 CHECK THE DTCs FROM THE ABS MODULE SELF-TEST
- Review the DTCs retrieved and recorded during Inspection and Verification.
- Are DTCs C109D, C109E and C109F present?
  - Yes : DIAGNOSE any vacuum sensor DTCs first, GO to Pinpoint Test I .
  - No : GO to T2.
T2 CHECK THE BRAKE VACUUM PUMP RELAY
- Disconnect: Brake Vacuum Pump Relay.
- Connect the scan tool.
- Enter the following diagnostic mode on the scan tool: DataLogger - ABS Module.
- Install a known good relay in place of the brake vacuum pump relay.
- Toggle the vacuum pump (VAC_PMP) active command ON.
- Does the brake vacuum pump run when commanded ON?
  - Yes : REMOVE the known good relay. INSTALL a new brake vacuum pump relay. CLEAR the DTCs. REPEAT the self-test.
  - No : REMOVE the known good relay. GO to T3.
T3 CHECK THE BRAKE VACUUM PUMP RELAY CONTROL CIRCUIT FOR A SHORT TO VOLTAGE
- Ignition ON.
- Measure the voltage between the brake vacuum pump relay circuit CCB30 (GY/VT) and ground.
  
  Fig 1: Measuring Voltage Between Brake Vacuum Pump Relay Circuit CCB30 (GY/VT) And Ground
  Courtesy of FORD MOTOR CO.
- Is any voltage present?
  - Yes : REPAIR circuit CCB30 (GY/VT). CLEAR the DTCs. REPEAT the self-test.
  - No : GO to T4.
T4 CHECK THE BRAKE VACUUM PUMP RELAY CONTROL CIRCUIT FOR AN OPEN
- Ignition OFF.
- Disconnect: ABS Module C135.
- Measure the resistance between ABS module C135-36, circuit CCB30 (GY/VT), harness side and brake vacuum pump relay circuit CCB30 (GY/VT).
  
  Fig 2: Measuring Resistance Between ABS Module C135-36, Circuit CCB30 (GY/VT) And Brake Vacuum Pump Relay Circuit CCB30 (GY/VT)
  Courtesy of FORD MOTOR CO.
- Is the resistance less than 5 ohms?
  - Yes : GO to T5.
  - No : REPAIR circuit CCB30 (GY/VT). CLEAR the DTCs. REPEAT the self-test.
T5 CHECK THE BRAKE VACUUM PUMP RELAY OUTPUT CIRCUIT FOR AN OPEN
- Ignition OFF.
- Disconnect: Brake Vacuum Pump C1560.
- Measure the resistance between brake vacuum pump relay circuit CCB29 (WH/GN) and brake vacuum pump C1560-1, circuit CCB29 (WH/GN), harness side.
  
  Fig 3: Measuring Resistance Between Brake Vacuum Pump Relay Circuit CCB29 (WH/GN) And Brake Vacuum Pump C1560-1, Circuit CCB29 (WH/GN)
  Courtesy of FORD MOTOR CO.
- Is the resistance less than 5 ohms?
  - Yes : GO to T6.
  - No : REPAIR circuit CCB29 (WH/GN). CLEAR the DTCs. REPEAT the self-test.
T6 CHECK THE BRAKE VACUUM PUMP RELAY OUTPUT CIRCUIT FOR A SHORT TO GROUND
- Measure the resistance between the brake vacuum pump relay circuit CCB29 (WH/GN) and ground.
  
  Fig 4: Measuring Resistance Between Brake Vacuum Pump Relay Circuit CCB29 (WH/GN) And Ground
  Courtesy of FORD MOTOR CO.
- Is the resistance greater than 10, 000 ohms?
  - Yes : GO to T7.
  - No : REPAIR circuit CCB29 (WH/GN). CLEAR the DTCs. REPEAT the self-test.
T7 CHECK THE BRAKE VACUUM PUMP GROUND CIRCUIT FOR AN OPEN
- Measure the resistance between the brake vacuum pump C1560-2, circuit GD123 (BK/GY), harness side and ground.
  
  Fig 5: Measuring Resistance Between Brake Vacuum Pump C1560-2, Circuit GD123 (BK/GY), Harness Side And Ground
  Courtesy of FORD MOTOR CO.
- Is the resistance less than 5 ohms?
  - Yes : GO to T8.
  - No : REPAIR circuit GD123 (BK/GY). CLEAR the DTCs. REPEAT the self-test.
T8 CHECK THE VOLTAGE TO THE BRAKE VACUUM PUMP RELAY
- Ignition ON.
- Measure the voltage between the brake vacuum pump relay circuit CBB52 (GN/WH) and ground; and between the brake vacuum pump relay circuit SBB64 (VT/RD) and ground.
  
  Fig 6: Measuring Voltage Between Brake Vacuum Pump Relay Circuit CBB52 (GN/WH) And Ground
  Courtesy of FORD MOTOR CO.
- Are the voltages greater than 10 volts?
  - Yes : GO to T9.
  - No : VERIFY that BJB fuse 64 (40A) and fuse 52 (5A) are OK.
    If OK, REPAIR circuit SBB64 (VT/RD) or CBB52 (GN/WH) for an open.
    
    If not OK, REFER to the Wiring Diagrams information to identify the possible causes of the circuit short. CLEAR the DTCs. REPEAT the self-test.
T9 CHECK THE BRAKE VACUUM PUMP OPERATION
- Ignition OFF.
- Connect: Vacuum Pump C1560.
- Connect: BJB Fuse 64 (40A).
- Momentarily, connect a fused jumper wire between brake vacuum pump relay circuit SBB64 (VT/RD) and brake vacuum pump relay circuit CCB29 (WH/GN).
  
  Fig 7: Connecting Fused Jumper Wire Between Brake Vacuum Pump Relay Circuit SBB64 (VT/RD) And Brake Vacuum Pump Relay Circuit CCB29 (WH/GN)
  Courtesy of FORD MOTOR CO.
- Does the vacuum pump run?
  - Yes : REMOVE the fused jumper wire. GO to T10.
  - No : REMOVE the fused jumper wire. INSTALL a brake new vacuum pump. REFER to POWER BRAKE ACTUATION . CLEAR the DTCs and REPEAT the self-test.
T10 CHECK FOR CORRECT ABS MODULE OPERATION
- Check ABS module connector for:
  - corrosion
  - damaged pins
  - pushed-out pins
- Connect: ABS Module.
- Connect: Vacuum Pump C1560.
- Connect: BJB Fuse 64 (40A).
- Connect: Brake Vacuum Pump Relay.
- Make sure each 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.