P0571-BRAKE SWITCH 1 PERFORMANCE

For a complete wiring diagram Refer to Section 8W

When Monitored:
With the ignition on and battery voltage greater than 10.4 volts.
Set Condition:
The PCM detects that the states of Brake Signal 1 and Brake Signal 2 do not match for more than 50 ms.

Possible Causes

INTERMITTENT DTC

(B15) BRAKE SIGNAL 1 CIRCUIT SHORTED TO GROUND

(B16) BRAKE SIGNAL 2 CIRCUIT SHORTED TO VOLTAGE

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

(Z967) GROUND CIRCUIT OPEN OR HIGH RESISTANCE

(B15) BRAKE SIGNAL 1 CIRCUIT OPEN OR HIGH RESISTANCE

(B16) BRAKE SIGNAL 2 CIRCUIT OPEN OR HIGH RESISTANCE

STOP LAMP SWITCH

POWERTRAIN CONTROL MODULE (PCM)

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE - STANDARD PROCEDURE)

Diagnostic Test

1.DTC IS ACTIVE

Do the states change from Pressed when the pedal is pressed to Not Pressed when the pedal is released?

Yes

Refer to the *CHECKING FOR AN INTERMITTENT DTC Diagnostic Procedure. (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING)

Go to 2

2.(B15) BRAKE SIGNAL 1 CIRCUIT

Does the test light change from illuminated when the pedal is pressed to not illuminated when the pedal is released?

Yes

Go to 3.

Go to 4

3.(B16) BRAKE SIGNAL 2 CIRCUIT

Does the test light change from illuminated when the pedal is pressed to not illuminated when the pedal is released?

Yes

Go to 11

Go to 7

4.(Z967) GROUND CIRCUIT OPEN OR HIGH RESISTANCE

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

Repair the (Z967) Ground circuit for an open circuit or high resistance.
Perform the PCM Verification Test Ver. 1 (Refer to 9 - ENGINE - STANDARD PROCEDURE).

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

Is the resistance above 100 ohms?

Yes

Go to 6

Repair the (B15) Brake Signal 1 circuit for a short to ground.
Perform the PCM Verification Test Ver. 1 (Refer to 9 - ENGINE - STANDARD PROCEDURE).

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

Is the resistance below 5.0 ohms?

Yes

Go to 10

Repair the (B15) Brake Signal 1 circuit for an open circuit or high resistance.
Perform the PCM Verification Test Ver. 1 (Refer to 9 - ENGINE - STANDARD PROCEDURE).

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

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

Repair the (F202) Fused Ignition Switch Output (Run-Start) circuit for an open circuit or high resistance.
Perform the PCM Verification Test Ver. 1 (Refer to 9 - ENGINE - STANDARD PROCEDURE).

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

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 (Refer to 9 - ENGINE - STANDARD PROCEDURE).

Go to 9

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

Is the resistance below 5.0 ohms?

Yes

Go to 10

Repair the (B16) Brake Signal 2 circuit for an open circuit or high resistance.
Perform the PCM Verification Test Ver. 1 (Refer to 9 - ENGINE - STANDARD PROCEDURE).

10.STOP LAMP SWITCH

Were any problems found?

Yes

Repair as necessary.
Perform the PCM Verification Test Ver. 1 (Refer to 9 - ENGINE - STANDARD PROCEDURE).

Replace the Stop Lamp Switch in accordance with the Service Information.
Perform the PCM Verification Test Ver. 1 (Refer to 9 - ENGINE - STANDARD PROCEDURE).

11.POWERTRAIN CONTROL MODULE (PCM)

Were any problems found?

Yes

Repair as necessary.
Perform the PCM Verification Test Ver. 1 (Refer to 9 - ENGINE - STANDARD PROCEDURE).

Replace and program the Powertrain Control Module (PCM) in accordance with the Service Information.
Perform the PCM Verification Test Ver. 1 (Refer to 9 - ENGINE - STANDARD PROCEDURE).