DTC Troubleshooting: P0504 (159)
  1. Check for continuity between ECM connector No. 2 terminal No. 38 and body ground.
Is there continuity?
YES -
Repair short in the wire between the brake pedal position switch and ECM connector No. 2 terminal No. 38, then go to Step 29 .
NO -
Go to Step 19 .
  1. Check the brake pedal position switch.
Is the brake pedal position switch OK?
YES -
Go to Step 34 .
NO -
Adjust or replace the brake pedal position switch, then go to Step 29 .
  1. Turn the ignition switch OFF.
  1. Disconnect the brake pedal position switch 4P connector.
  1. Turn the ignition switch ON (II).