DTC P0504: Brake Pedal Position Switch Circuit Malfunction

1. Turn the ignition switch ON (II).

1. Check BRAKE PEDAL POSITION SWITCH B in the DATA LIST with the HDS when the brake pedal pressed.

Is ON indicated?

YES | - | Go to Step 3 .
NO | - | Check the brake pedal position switch, then go to Step 29 .

1. Check BRAKE PEDAL POSITION SWITCH A in the DATA LIST with the HDS when the brake pedal pressed.

Is ON indicated?

YES | - | Go to Step 4 .
NO | - | Go to Step 7 .

1. Release the brake pedal.

1. Check BRAKE PEDAL POSITION SWITCH B in the DATA LIST with the HDS.

Is OFF indicated?

YES | - | Go to Step 6 .
NO | - | Go to Step 20 .

1. Check BRAKE PEDAL POSITION SWITCH A in the DATA LIST with the HDS.

Is OFF indicated?

YES | - | Intermittent failure, system is OK at this time. Check for poor connections or loose terminals at the brake pedal position switch and at the ECM.■
NO | - | Check the brake pedal position switch, then go to Step 29 .

1. Check the brake lights.

Do the brake lights come on?

YES | - | Go to Step 8 .
NO | - | Go to Step 12 .

1. Turn the ignition switch OFF, and wait 30 seconds.

1. Disconnect the brake pedal position switch 4P connector.

1. Disconnect ECM connector No. 2 (58P).

1. Check for continuity between ECM connector No. 2 terminal No. 38 and brake pedal position switch 4P connector terminal No. 2.

Is there continuity?

YES | - | Go to Step 34 .
NO | - | Repair open in the wire between the brake pedal position switch and ECM connector No. 2 terminal No. 38, then go to Step 30 .

1. Turn the ignition switch OFF.

1. Disconnect the brake pedal position switch 4P connector.