P0573
P0573-HIGH VOLTAGE DETECTED AT THE BRAKE SWITCH
For complete wiring diagrams refer to Diagrams/Electrical.
- When Monitored:
While the ignition is on.
- Set Condition:
The brake switch status is = to ON and the not brake switch status is = to OFF for a calibrated amount of time.
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding.
1. BRAKE SWITCH CIRCUIT OPEN
Turn the ignition off.
Disconnect the brake switch connection. Inspect the pins and connector for damage, corrosion, etc.
Disconnect the ECM connectors. Inspect the pins and connector for damage, corrosion, etc.
NOTE: Check connectors - Clean/repair as necessary.
Measure the resistance between the brake switch signal circuits in the ECM connector and the brake switch connector.
Is the resistance less than 10 ohms?
Yes
- Go To 2
No
- Repair the open brake switch circuits.
- Perform POWERTRAIN VERIFICATION TEST. Powertrain Verification Test
2. BRAKE SWITCH CIRCUIT SHORTED TO VOLTAGE
Measure the voltage on both brake switch circuits in the ECM connector.
Is the voltage less than 1 volt for each circuit?
Yes
- Go To 3
No
- Repair the open or short to ground in the Brake Switch circuits.
- Perform POWERTRAIN VERIFICATION TEST. Powertrain Verification Test
3. ECM
Reconnect the ECM connectors.
Install a jumper wire in the brake switch connector between signal circuit and to ground.
Turn the ignition on.
Using the scan tool, read the DTCs.
Cycle the brake pedal several times.
Is the DTC for brake switch low voltage present?
Yes
- Go To 4
No
- Replace the ECM.
- Perform POWERTRAIN VERIFICATION TEST. Powertrain Verification Test
4. BRAKE SWITCH
Reconnect the brake switch connector.
Using the scan tool, clear the DTCs.
Turn the ignition on.
Cycle the brake pedal several times.
Using the scan tool, read the DTCs.
Has the brake switch High DTC returned?
Yes
- Replace the brake switch.
- Perform POWERTRAIN VERIFICATION TEST. Powertrain Verification Test
No
- Perform INTERMITTENT CONDITION Test. Intermittent Condition