Pinpoint Test H: The Red Brake Warning Indicator Does Not Self-Check

H1 CHECK CIRCUIT 31S-CF45 (BK/GN) FOR A SHORT TO POWER 

• Key in OFF position.
• Disconnect: ABS Module C135.
• Disconnect: Instrument Cluster C220a.
• Key in ON position.
• Measure the voltage between the instrument cluster C220a pin 7, circuit 31S-CF45 (BK/GN), harness side and ground.
  Fig 1: Measuring Voltage Between Instrument Cluster C220A Pin 7, Circuit 31S-CF45 (BK/GN), Harness Side And Ground

  Courtesy of FORD MOTOR CO.
• Is voltage present? 

Yes 

REPAIR the circuit. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.

No 

Go to H2.

H2 CHECK CIRCUIT 31S-CF45 (BK/GN) FOR AN OPEN OR SHORT TO GROUND 

• Key in OFF position.
• Measure the resistance between the ABS module C135 pin 39, circuit 31S-CF45 (BK/GN), harness side and the instrument cluster C220a pin 7, circuit 31S-CF45 (BK/GN), harness side, and between the ABS module C135 pin 39, 31S-CF45 (BK/GN), harness side and ground.
  Fig 2: Checking Circuit 31S-CF45 (BK/GN) For Open Or Short To Ground

  Courtesy of FORD MOTOR CO.
• Is the resistance less than 5 ohms between the ABS module and the instrument cluster and greater than 10,000 ohms between the ABS module and ground? 

Yes 

Go to H3.

No 

REPAIR the circuit. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.

H3 CHECK THE INSTRUMENT CLUSTER 

• Connect: Instrument Cluster C220a.
• Key in ON position.
• Connect a fused (10A) jumper wire between the ABS module C135 pin 39, circuit 31S-CF45 (BK/GN), harness side and ground.
  Fig 3: Checking Instrument Cluster

  Courtesy of FORD MOTOR CO.
• Does the instrument cluster red brake warning indicator turn off? 

Yes 

INSTALL a new ABS module. REFER to HYDRAULIC CONTROL UNIT (HCU) . REPEAT the self-test. TEST the system for normal operation.

No 

INSTALL a new instrument cluster. REFER to INSTRUMENT CLUSTER . CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.