Pinpoint Test D: DTC B1484 - Brake Pedal Input Open Circuit

WARNING: This page is about a different car, the 2006 Mercury Grand Marquis and 2006 Ford Crown Victoria. However, it is still accessible from the selected car via links, so may be relevant.

CAUTION: The Flex Probe Kit must be used for all test connections. Use of standard multimeter probes may damage wiring terminals.

D1 CHECK THE BRAKE LAMP OPERATION
- Press the brake pedal.
- Do the brake lamps illuminate?
Yes : GO to D2.

No : REFER to EXTERIOR LIGHTING .
D2 CHECK THE ANTI-LOCK BRAKE SYSTEM (ABS) MODULE BOO_ABS PID
- Connect the scan tool.
- Key in ON position.
- Using the diagnostic tool, monitor the ABS module BOO_ABS PID while pressing and releasing the brake pedal.
- Does the ABS module BOO_ABS PID indicate ON with the brake pedal pressed and OFF with the brake pedal released?
Yes : CLEAR the DTCs. REPEAT the self-test. If DTC B1484 is retrieved, INSTALL a new ABS module. REFER to ANTI-LOCK BRAKE SYSTEM (ABS) MODULE . REPEAT the self-test.

No : GO to D3.
D3 CHECK CIRCUIT 1651 (WH/RD) FOR AN OPEN
NOTE: Make sure the brake pedal is released for this step.
- Disconnect: ABS Module C135.
- Press and hold the brake pedal.
- Measure the voltage between ABS module C135-6, circuit 1651 (WH/RD), harness side and the ABS module C135-12, circuit 57 (BK), harness side.
  
  Fig 1: Measuring Voltage Between ABS Module C135-6, Circuit 1651 (WH/RD) And ABS Module C135-12, Circuit 57 (BK)
  Courtesy of FORD MOTOR CO.
- Is the voltage greater than 10 volts?
Yes : INSTALL a new ABS module. REFER to ANTI-LOCK BRAKE SYSTEM (ABS) MODULE . TEST the system for normal operation.

No : VERIFY CJB fuse 5 (10A) is OK. If OK, REPAIR circuit 1651 (WH/RD) for an open. CLEAR the DTCs. TEST the system for normal operation.