P0573

P0573-BRAKE SWITCH 1 STUCK OFF





For a complete wiring diagram refer to Diagrams/Electrical.

- When Monitored:

With the ignition on, battery voltage greater than 10.4 volts, ambient temperature above -23° C.

- Set Condition:

The PCM detects that the state of Brake Signal 1 does not change as expected.





Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding.

Diagnostic Test

1. DTC IS ACTIVE

Turn the ignition on.

With the scan tool, monitor the states of Brake Signal 1 and Brake Signal 2 while pressing and releasing the brake pedal several times.

Do the Brake Signal states change appropriately as the pedal is pressed and released?

Yes

- Refer to the *CHECKING FOR AN INTERMITTENT DTC Diagnostic Procedure. Checking for an Intermittent DTC

No

- Go To 2

2. (B15) BRAKE SIGNAL 1 CIRCUIT





Turn the ignition off.

Disconnect the Powertrain Control Module (PCM) connector.

Using a 12 volt test light connected to 12 volts, check the (B15) Brake Signal 1 circuit in the Powertrain Control Module (PCM) harness connector while pressing and releasing the brake pedal several times.

Does the test light change from illuminated to not illuminated as the brake pedal is pressed and released?

Yes

- Go to 3

No

- Go to 4

3. (B16) BRAKE SIGNAL 2 CIRCUIT





Turn the ignition on.

Using a 12 volt test light connected to ground, check the (B16) Brake Signal 2 circuit in the Powertrain Control Module (PCM) harness connector while pressing and releasing the brake pedal several times.

Does the test light change from illuminated to not illuminated as the brake pedal is pressed and released?

Yes

- Go to 11

No

- Go to 7

4. (Z967) GROUND CIRCUIT OPEN OR HIGH RESISTANCE





Turn the ignition off.

Disconnect the Stop Lamp Switch connector.

Using a 12 volt test light connected to 12 volts, check the (Z967) Ground circuit in the Stop Lamp Switch harness connector.

NOTE: The test light should be illuminated and bright. Compare the brightness to that of a direct connection to the battery.

Is the test light illuminated and bright?

Yes

- Go to 5

No

- Repair the (Z967) Ground circuit for an open circuit or high resistance.
- Perform the PCM Verification Test Ver. 1. PCM Verification Test

5. (B15) BRAKE SIGNAL 1 CIRCUIT SHORTED TO GROUND





Measure the resistance between ground and the (B15) Brake Signal 1 circuit in the Stop Lamp Switch harness connector.

Is the resistance above 100 ohms?

Yes

- Go to 6

No

- Repair the (B15) Brake Signal 1 circuit for a short to ground.
- Perform the PCM Verification Test Ver. 1. PCM Verification Test

6. (B15) BRAKE SIGNAL 1 CIRCUIT OPEN OR HIGH RESISTANCE





Measure the resistance of the (B15) Brake Signal 1 circuit between the Stop Lamp Switch harness connector and the Powertrain Control Module (PCM) harness connector.

Is the resistance below 5.0 ohms?

Yes

- Go to 10

No

- Repair the (B15) Brake Signal 1 circuit for an open circuit or high resistance.
- Perform the PCM Verification Test Ver. 1. PCM Verification Test

7. (F202) FUSED IGNITION SWITCH OUTPUT (RUN-START) CIRCUIT OPEN OR HIGH RESISTANCE





Turn the ignition off.

Disconnect the Stop Lamp Switch connector.

Turn the ignition on.

Using a 12 volt test light connected to ground, check the (F202) Fused Ignition Switch Output (Run-Start) circuit in the Stop Lamp Switch harness connector.

NOTE: The test light should be illuminated and bright. Compare the brightness to that of a direct connection to the battery.

Is the test light illuminated and bright?

Yes

- Go to 8

No

- Repair the (F202) Fused Ignition Switch Output (Run-Start) circuit for an open circuit or high resistance.
- Perform the PCM Verification Test Ver. 1. PCM Verification Test

8. (B16) BRAKE SIGNAL 2 CIRCUIT SHORTED TO VOLTAGE





Measure the voltage of the (B16) Brake Signal 2 circuit in the Stop Lamp Switch harness connector.

Is there any voltage present?

Yes

- Repair the (B16) Brake Signal 2 circuit for a short to voltage.
- Perform the PCM Verification Test Ver. 1. PCM Verification Test

No

- Go to 9

9. (B16) BRAKE SIGNAL 2 CIRCUIT OPEN OR HIGH RESISTANCE





Measure the resistance of the (B16) Brake Signal 2 circuit between the Stop Lamp Switch harness connector and the Powertrain Control Module (PCM) harness connector.

Is the resistance below 5.0 ohms?

Yes

- Go to 10

No

- Repair the (B16) Brake Signal 2 circuit for an open circuit or high resistance.
- Perform the PCM Verification Test Ver. 1. PCM Verification Test

10. STOP LAMP SWITCH

Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Stop Lamp Switch and the Powertrain Control Module (PCM).

Look for any chafed, pierced, pinched, or partially broken wires.

Look for broken, bent, pushed out or corroded terminals.

Monitor the scan tool data relative to this circuit and wiggle test the wiring and connectors.

Look for the data to change or for the DTC to reset during the wiggle test.

Refer to any Technical Service Bulletins that may apply.

Were any problems found?

Yes

- Repair as necessary.
- Perform the PCM Verification Test Ver. 1. PCM Verification Test

No

- Replace the Stop Lamp Switch.
- Perform the PCM Verification Test Ver. 1. PCM Verification Test

11. POWERTRAIN CONTROL MODULE (PCM)

Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Stop Lamp Switch and the Powertrain Control Module (PCM).

Look for any chafed, pierced, pinched, or partially broken wires.

Look for broken, bent, pushed out or corroded terminals.

Refer to any Technical Service Bulletins that may apply.

Were any problems found?

Yes

- Repair as necessary.
- Perform the PCM Verification Test Ver. 1. PCM Verification Test

No

- Replace and program the Powertrain Control Module (PCM).
- Perform the PCM Verification Test Ver. 1. PCM Verification Test