P0571-BRAKE SWITCH 1 PERFORMANCE

For a complete wiring diagram Refer to Section 8W.

Theory of Operation

The Transmission Control Module (TCM) monitors the brake switch 1 signal over the CAN Bus. If the Transmission is shifted into any valid gear position without confirming that the brake was depressed before the shift, a DTC will set.

When Monitored:
After initial start and any time the shift lever is changed from park to reverse, drive or neutral.
System voltage between 9.0 and 16 volts.
No active CAN Bus DTCs present.
Set Condition:
The brake switch status does not change during a drive cycle with a vehicle speed greater than 30 Km/h (18.5 mph) for the period of 10 seconds.
It take to consecutive problem identification trips to set the MIL.

Possible Causes

ENGINE BRAKE SWITCH DTCS PRESENT

TRANSMISSION CONTROL MODULE

Always perform the CVT Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 21 - TRANSMISSION/TRANSAXLE/AUTOMATIC - CVT - STANDARD PROCEDURE)

Diagnostic Test

1. CHECK IF THE DTC IS ACTIVE

With the scan tool, read Transmission DTCs.

Is the status Active for this DTC or is the STARTS SINCE SET counter 2 or less?

Yes

Go To 2

Go To 4

2. CHECK FOR ENGINE BRAKE SWITCH DTCS

With the scan tool, check for engine brake switch DTCs.
With the scan tool, check if the brake switch changes when the brake pedal is pressed.

Are there any engine brake switch DTCs present or is the brake switch not registering any change on the scan tool?

Yes

Refer to the engine Diagnosis and Testing category and perform the appropriate symptom. If no DTCs are present and the brake switch does not seem to function, diagnose the brake switch as though a valid DTC is present.

Perform CVT VERIFICATION TEST. (Refer to 21 - TRANSMISSION/TRANSAXLE/AUTOMATIC - CVT - STANDARD PROCEDURE)

Go To 3

3. CHECK OTHER CONTROLLERS FOR BRAKE SWITCH DTCS

With the scan tool check other controllers for Brake Switch DTCs.

Do any other controllers report a Brake Switch DTC?

Yes

Refer to the Engine Diagnosis and Testing category and perform diagnostics for P0571 as though the DTC is active.

Perform CVT VERIFICATION TEST. (Refer to 21 - TRANSMISSION/TRANSAXLE/AUTOMATIC - CVT - STANDARD PROCEDURE)

Using the schematics as a guide, check the Transmission Control Module (TCM) terminals for corrosion, damage, or terminal push out. Pay particular attention to all power and ground circuits. Check for any Service Bulletins for possible causes that may apply. If no problems are found, replace the TCM per the Service Information.
Perform CVT VERIFICATION TEST. (Refer to 21 - TRANSMISSION/TRANSAXLE/AUTOMATIC - CVT - STANDARD PROCEDURE)

4. INTERMITTENT WIRING AND CONNECTORS

The conditions necessary to set this DTC are not present at this time.
Using the schematics as a guide, inspect the wiring and connectors specific to this circuit.
Wiggle the wires while checking for shorted and open circuits.

Were there any problems found?

Yes

Repair as necessary.

Perform CVT VERIFICATION TEST. (Refer to 21 - TRANSMISSION/TRANSAXLE/AUTOMATIC - CVT - STANDARD PROCEDURE)

Test Complete.