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Pinpoint Test O: The Brake Warning Indicator Is Never/Always On

  1. O1 CHECK IF THE GEM IS RECEIVING THE CORRECT IGNITION SWITCH STATUS 
    CAUTION: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may damage the connector.
    • Connect the diagnostic tool.
    • Key in ON position.
    • Enter the following diagnostic mode on the diagnostic tool: Generic Electronic Module (GEM) PID.
    • Monitor GEM PIDs IGN_KEY, IGN_S, IGN_R, and IGN_A while cycling the ignition switch through all positions and then removing the key from ignition switch.
    • Do the PIDs agree with the ignition switch status? 
    1. Yes:  GO to O2.
    2. No:  REFER to STEERING COLUMN SWITCHES .
  2. O2 DETERMINE IF GEM IS RECEIVING THE CORRECT PARKING BRAKE INPUT 
    • Monitor GEM PID PRK_BRK while applying and releasing the parking brake.
    • Did the PID read ON with the parking brake applied, and OFF with the parking brake released? 
    1. Yes:  GO to O3.
    2. No:  GO to  O5 .
  3. O3 DETERMINE IF BRAKE WARNING INDICATOR CIRCUIT IS OPEN OR GROUNDED 
    • Verify that the parking brake is released.
    • Is the instrument cluster BRAKE warning indicator off? 
    1. Yes:  GO to O4.
    2. No:  GO to  O13 .
  4. O4 DETERMINE IF GEM IS SENDING THE CORRECT OUTPUT SIGNAL 
    • Trigger the GEM active command BKFLD LOW.
    • Did the instrument cluster BRAKE warning indicator illuminate? 
    1. Yes:  GO to  O14 .
    2. No:  GO to  O11 .
  5. O5 CHECK CIRCUIT BETWEEN THE PARKING BRAKE SWITCH AND THE GEM FOR A SHORT TO GROUND 
    • Monitor PID PRK_BRK while applying and releasing then parking brake.
    • Did the PID read ON with the parking brake applied and with the parking brake released? 
    1. Yes:  GO to  O9 .
    2. No:  GO to O6.
  6. O6 CHECK CIRCUIT 128 (VT/YE) AND CIRCUIT 22 (LB/BK) FOR AN OPEN 
    • Key in OFF position.
    • Disconnect: Parking Brake Switch C306.
    • Disconnect: GEM C201d.
    • Measure the resistance between the GEM C201d pin 4, circuit 128 (VT/YE), harness side and the parking brake switch C306 pin 1, circuit 22 (LB/BK), harness side.
      Fig 1: Checking Circuit 128 (VT/YE) And Circuit 22 (LB/BK) For Open
      G03242529Courtesy of FORD MOTOR CO.
    • Is the resistance less than 5 ohms? 
    1. Yes:  GO to O7.
    2. No:  REPAIR the circuit. TEST the system for normal operation.
  7. O7 CHECK CIRCUIT 1205 (BK) FOR AN OPEN 
    • Measure the resistance between the parking brake switch C306 pin 2, circuit 1205 (BK), harness side and ground.
      Fig 2: Checking Circuit 1205 (BK) For Open
      G03242530Courtesy of FORD MOTOR CO.
    • Is the resistance less than 5 ohms? 
    1. Yes:  GO to O8.
    2. No:  REPAIR the circuit. TEST the system for normal operation.
  8. O8 CHECK CIRCUIT 128 (VT/YE) FOR AN OPEN ON THE PARKING BRAKE SWITCH 
    • Monitor PID while connecting and disconnecting a fused (5A) jumper wire to C306.
      Fig 3: Checking Circuit 128 (VT/YE) For Open On Parking Brake Switch
      G03242531Courtesy of FORD MOTOR CO.
    • Does the PID read ON with the wire connected and OFF with the wire disconnected? 
    1. Yes:  INSTALL a new parking brake switch. REFER to ANTI-LOCK CONTROL - REAR or ANTI-LOCK CONTROL-TRACTION CONTROL . TEST the system for normal operation.
    2. No:  GO to  O16 .
  9. O9 CHECK CIRCUIT 128 (VT/YE) FOR A CLOSED PARKING BRAKE SWITCH 
    • Key in OFF position.
    • Disconnect: Parking Brake Switch C306.
    • Key in ON position.
    • Does indicator continue to illuminate? 
    1. Yes:  GO to O10.
    2. No:  INSTALL a new parking brake switch. REFER to ANTI-LOCK CONTROL - REAR or ANTI-LOCK CONTROL-TRACTION CONTROL . TEST the system for normal operation.
  10. O10 CHECK CIRCUIT 128 (VT/YE) FOR A SHORT TO GROUND 
    • Key in OFF position.
    • Disconnect: Parking Brake Switch C306.
    • Disconnect: GEM C201d.
    • Measure the resistance between the GEM C201d pin 4, circuit 128 (VT/YE), harness side and ground.
      Fig 4: Checking Circuit 128 (VT/YE) For Short To Ground
      G03242532Courtesy of FORD MOTOR CO.
    • Is the resistance greater than 10,000 ohms? 
    1. Yes:  REPAIR or INSTALL a new parking brake switch as needed. TEST the system for normal operation.
    2. No:  REPAIR the circuit. TEST the system for normal operation.
  11. O11 CHECK CIRCUIT 128 (VT/YE) FOR A SHORT TO BATTERY 
    • Key in OFF position.
    • Disconnect: GEM C201e.
    • Disconnect: Instrument Cluster C220b.
    • Key in ON position.
    • Measure the voltage between the GEM C201e pin 13, circuit 128 (VT/YE), harness side and ground.
      Fig 5: Checking Circuit 128 (VT/YE) For Short To Battery
      G03242533Courtesy of FORD MOTOR CO.
    • Is any voltage indicated? 
    1. Yes:  REPAIR the circuit. TEST the system for normal operation.
    2. No:  GO to O12.
  12. O12 CHECK CIRCUIT 128 (VT/YE) FOR AN OPEN 
    • Key in OFF position.
    • Measure the resistance between the GEM C201e pin 13, circuit 128 (VT/YE), harness side and the instrument cluster C220b pin 14, circuit 128 (VT/YE), harness side.
      Fig 6: Checking Circuit 128 (VT/YE) For Open
      G03242534Courtesy of FORD MOTOR CO.
    • Is the resistance less than 5 ohms? 
    1. Yes:  GO to  O17 .
    2. No:  REPAIR the circuit. TEST the system for normal operation.
  13. O13 CHECK THE BRAKE FLUID LEVEL SWITCH FOR AN INTERNAL GROUND 
    • Key in OFF position.
    • Disconnect: Brake Fluid Level Switch C124.
    • Key in ON position.
    • With the parking brake released, observe the BRAKE warning indicator.
    • Is the BRAKE warning indicator always on? 
    1. Yes:  GO to O14.
    2. No:  INSTALL a new brake fluid level switch. TEST the system for normal operation.
  14. O14 DETERMINE IF THE GEM IS INTERNALLY GROUNDED 
    • Key in OFF position.
    • Disconnect: GEM C201e.
    • Key in ON position.
    • Observe the BRAKE warning indicator.
    • Is BRAKE warning indicator always on? 
    1. Yes:  GO to O15.
    2. No:  GO to  O16 .
  15. O15 CHECK CIRCUIT 128 (VT/YE) FOR A SHORT TO GROUND BETWEEN THE GEM AND THE INSTRUMENT CLUSTER 
    • Key in OFF position.
    • Disconnect: Instrument Cluster C220b.
    • Measure the resistance between the GEM C201e pin 13, circuit 128 (VT/YE), harness side and ground.
      Fig 7: Checking Circuit 128 (VT/YE) For Short To Ground Between Gem And Instrument Cluster
      G03242535Courtesy of FORD MOTOR CO.
    • Is resistance greater than 10,000 ohms? 
    1. Yes:  GO to  O17 .
    2. No:  REPAIR the circuit. TEST the system for normal operation.
  16. O16 CHECK FOR CORRECT GEM OPERATION 
    • Disconnect all the GEM connectors.
    • Check for:
      • corrosion
      • pushed-out pins
    • Connect all the GEM connectors and make sure they seat correctly.
    • Operate the system and verify the concern is still present.
    • Is the concern still present? 
    1. Yes:  INSTALL a new GEM. REFER to MULTIFUNCTION ELECTRONIC MODULE . TEST the system for normal operation.
    2. 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.
  17. O17 CHECK FOR CORRECT INSTRUMENT CLUSTER OPERATION 
    • Disconnect all the instrument cluster connectors.
    • Check for:
      • corrosion
      • pushed-out pins
    • Connect all the instrument cluster connectors and make sure they seat correctly.
    • Operate the system and verify the concern is still present.
    • Is the concern still present? 
    1. Yes:  INSTALL a new instrument cluster. REFER to INSTRUMENT CLUSTER  . TEST the system for normal operation.
    2. No:  The system is operating correctly at this time. The concern may have been caused y a loose or corroded connector. CLEAR the DTCs. REPEAT the self-test.
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