P0573-BRAKE SWITCH #1 CIRCUIT HIGH
When Monitored: Ignition on.
Set Condition: When the PCM recognizes Brake Switch is stuck in the high/off position. One Trip Fault. Three good trips to turn off the MIL.
Good Trip Equals to Zero
Brake Lamp Switch Operation
(K29) Brake Switch Signal Circuit Open
(Z1) Ground Circuit Open
1. Turn the ignition off. Disconnect the Brake Lamp Switch harness connector. Measure the resistance between the (Z1) Ground circuit terminal and the (K29) Brake Switch Signal circuit terminal in the Brake Lamp Switch. Apply and release the brake pedal while monitoring the ohmmeter. Does the resistance change from below 5.0 ohms to an open circuit? Yes --> Go To 2, No --> Replace the Brake Lamp Switch.
2. Turn the ignition off. Disconnect the PCM harness
DO NOT PROBE THE PCM HARNESS CONNECTORS.
PROBING THE PCM HARNESS CONNECTORS WILL DAMAGE THE PCM TERMINALS RESULTING IN
POOR TERMINAL TO PIN CONNECTION. INSTALL
MILLER SPECIAL TOOL #8815 TO PERFORM DIAGNOSIS.
Measure the resistance of the (K29) Brake Switch Signal circuit from the Brake Lamp Switch harness connector to the appropriate terminal of special tool #8815. Is the resistance below 5.0 ohms? Yes --> Go To 3, No --> Repair the open in the (K29) Brake Switch Signal circuit.
3. Measure the resistance between the (Z2) Ground circuit and ground at the Brake Lamp Switch harness connector. Is the resistance below 5.0 ohms? Yes --> Go To 4, No --> Repair the open in the (Z1) Ground circuit.
4. NOTE: Before continuing, check the PCM harness connector terminals for corrosion, damage, or terminal push out. Repair as necessary.
Using the schematics as a guide, inspect the wire harness and connectors. Pay particular attention to all Power and Ground circuits. If there are no possible causes remaining, view repair. Repair, Replace and
program the Powertrain Control Module in Accordance Service Information.
***It not necessarily the brake switch itself, rather you have an open circuit on the brake light wiring***
Tuesday, February 3rd, 2009 AT 11:12 PM