Pinpoint Test A: The Red Brake Warning Indicator Is Always On

WARNING: This page is about a different car, the 2005 Ford RV Cutaway, 2005 Ford Econoline, 2005 Ford E450 Super Duty, and 2005 Ford Cutaway. However, it is still accessible from the selected car via links, so may be relevant.

A1 CHECK THE PARKING BRAKE SWITCH
NOTE: Verify that the parking brake pedal is in the fully released position.
- Disconnect: Parking Brake Switch C2015.
- Key in ON position.
- Is the brake indicator lamp illuminated?
- Yes : GO to A2.
- No : If the parking brake is fully released, INSTALL a new parking brake switch. TEST the system for normal operation.
A2 CHECK CIRCUIT 162 (LG/RD) FOR A SHORT TO GROUND
- Key in OFF position.
- Disconnect: Instrument Cluster C220b.
- Measure the resistance between the parking brake switch C2015 pin 1, circuit 162 (LG/RD), harness side and ground.
  
  Fig 1: Measuring Resistance Between Parking Brake Switch Terminal 1 To Ground
  Courtesy of FORD MOTOR CO.
- Is the resistance greater than 10,000 ohms?
- Yes : GO to A3.
- No : REPAIR the circuit. TEST the system for normal operation.
A3 ISOLATE THE BRAKE MASTER CYLINDER FLUID LEVEL SWITCH
- Connect: Instrument Cluster C220b.
- Disconnect: Brake Fluid Level Switch C124.
- Key in ON position.
- Connect a fused jumper wire between the brake fluid level switch C124 pin 2, circuit 531 (DG/YE), harness side and the brake fluid level switch C124 pin 3, circuit 512 (TN/LG), harness side.
  
  Fig 2: Connecting Fused Jumper Wire Between Pins 2 & 3
  Courtesy of FORD MOTOR CO.
- Is the brake indicator lamp on?
- Yes : GO to A4.
- No : INSTALL a new brake fluid level switch. TEST the system for normal operation.
A4 CHECK CIRCUIT 512 (TN/LG) AND CIRCUIT 531 (DG/YE) FOR A SHORT TO GROUND
- Key in OFF position.
- Disconnect: Instrument Cluster C220b.
- Measure the resistance between the instrument cluster C220b pin 20, circuit 512 (TN/LG), harness side and ground and between the instrument cluster C220b pin 19, circuit 531 (DG/YE), harness side and ground.
  
  Fig 3: Measuring Resistance Between Pins 20 & 19
  Courtesy of FORD MOTOR CO.
- Are the resistances greater than 10,000 ohms?
- Yes : GO to A5.
- No : REPAIR the circuit(s) in question. TEST the system for normal operation.
A5 CHECK CIRCUIT 512 (TN/LG) AND CIRCUIT 531 (DG/YE) FOR AN OPEN
- Measure the resistance between the instrument cluster C220b pin 20, circuit 512 (TN/LG), harness side and the brake fluid level switch C124 pin 3, circuit 512 (TN/LG), harness side.
  
  Fig 4: Measuring Resistance Between Pins 20 & 3
  Courtesy of FORD MOTOR CO.
- Measure the resistance between the instrument cluster C220b pin 19, circuit 531 (DG/YE), harness side and the brake fluid level switch C124 pin 2, circuit 531 (DG/YE), harness side.
  
  Fig 5: Measuring Resistance Between Pins 19 & 2
  Courtesy of FORD MOTOR CO.
- Are the resistances less than 5 ohms?
- Yes : GO to A6.
- No : REPAIR the circuit(s) in question. TEST the system for normal operation.
A6 CHECK FOR CORRECT INSTRUMENT CLUSTER OPERATION
- Disconnect all instrument cluster connectors.
- Check for:
  - corrosion
  - pushed-out pins
- Connect all instrument cluster connectors and make sure they seat correctly.
- Operate the system and verify if the concern is still present.
- Is the concern still present?
- Yes : INSTALL a new instrument cluster. REFER to INSTRUMENT CLUSTER . 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. TEST the system for normal operation.