FREE REPAIR MANUALS & LABOR GUIDES 1982-2013 Vehicles
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P0504

DTC P0504 BRAKE SWITCH "A"/"B" CORRELATION

CIRCUIT DESCRIPTION

DTC Detection Condition:







In addition to turning on the stop lamps, the stop lamp switch signals are used for a variety of engine, transmission, and suspension functions. The stop lamp switch is designed with two complementary signal outputs: STP and ST1-. The ECM analyzes these signal outputs to detect malfunctions in the stop lamp switch.

HINT: Normal condition is as shown in the table.The signals can be read using the hand-held tester.

Wiring Diagram Part 1:




Wiring Diagram Part 2:






Step 1 - 3:




Step 4:




INSPECTION PROCEDURE

CHECK FOR INTERMITTENT PROBLEMS

HINT: Inspect the vehicle's ECM using check mode. Intermittent problems are easier to detect when the hand-held tester is in check mode. In check mode, the hand-held tester uses 1 trip detection logic, which has a higher sensitivity to malfunctions than normal mode (default), which uses 2 trip detection logic.

a. Clear the DTCs
b. Set the check mode
c. Perform a simulation test.
d. Check the connector and terminal
e. Wiggle the harness and the connector