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

Refer to appropriate SYSTEM WIRING DIAGRAMS article, Vehicle Dynamic Systems for schematic and connector information.

Normal Operation 

Fused battery voltage is sent to the brake pedal position (BPP) switch from battery junction box (BJB) fuse 14 (20A) along circuit 1119 (RD). When the brake pedal is pressed, the BPP switch closes and the voltage is then supplied to the ABS module along circuit 1651 (WH/RD). The ABS module is provided a ground along circuit 57 (BK).

This pinpoint test is intended to diagnose the following:

• Fuse(s)
• Wiring, terminals or connectors
• BPP switch
• ABS module

PINPOINT TEST D: DTC B1484 - BRAKE PEDAL INPUT OPEN CIRCUIT 

1. D1 CHECK THE STOPLAMP OPERATION 
   • Press the brake pedal.
   • Do the stoplamps illuminate? 
   1. YES  : Go to  D2.
   2. NO  : REFER to EXTERIOR LIGHTING article to diagnose the stoplamps.
2. D2 CHECK THE ABS MODULE BRAKE ON/OFF (BOO) PID (BOO_ABS) 
   • Connect the diagnostic tool.
   • Key in ON position.
   • Enter the following diagnostic mode on the diagnostic tool: ABS DataLogger
   • Monitor the 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? 
   1. 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.
   2. NO  : Go to  D3.
3. D3 CHECK THE VOLTAGE TO THE ABS MODULE 
   NOTE: Make sure the brake pedal is released for this step.