Brakes - Abnormal Noise When Brake Pedal Released

T-SB-0363-10

December 22, 2010

Abnormal Noise when Brake Pedal Released

Service Category
Brake

Section
Brake Control/Dynamic Control System

Market
USA





Applicability

Introduction

Some 2010 Prius and early produced 2011 Prius vehicles may exhibit an abnormal noise when the brake pedal is released. The noise is typically heard when the vehicle is stopped. The ABS Actuator Skid Control Electronic Control Unit (ECU) calibration software has been revised to eliminate this noise.

See video below for an example of the abnormal noise.

Prius Abnormal Brake Noise

Production Change Information





This TSB applies to vehicles produced BEFORE the Production Change Effective VINs shown.





Warranty Information

APPLICABLE WARRANTY

^ This repair is covered under the Toyota Comprehensive Warranty. This warranty is in effect for 36 months or 36,000 miles, whichever occurs first, from the vehicle's in-service date.

^ Warranty application is limited to occurrence of the specified condition described in this bulletin.





Calibration Information





Required Tools & Equipment

Repair Procedure

1. Confirm the abnormal (squawk/honk) noise when releasing the brake pedal.

2. Connect the GR8 Battery Diagnostic Station to the vehicle and turn it ON, then select Power Supply Mode.

NOTE

^ The GR8 Battery Diagnostic Station MUST be used in Power Supply Mode to maintain battery voltage at 13.5 volts while flash reprogramming the vehicle.

^ For details on how to use the GR8 Battery Diagnostic Station, refer to the located on the Technical Information System (TIS), Diagnostics - Tools & Equipment - Battery Diagnostics.

^ If the GR8 Battery Diagnostic Station is unavailable, the PSC Power Supply Charger / Maintainer (MTRPSC55OSKT) may be used.

3. Verify the vehicle's applicability for recalibration.

A. Connect Techstream and establish a vehicle connection.





B. Click the Health Check button on the System Select tab (see Figure 1).





C. Choose Chassis ECU group in the Health Check dialog box.

D. Click Next.





E. Click Continue to view Health Check results.





F. Available calibration updates are indicated by a link in the Calibration Update column. STOP before clicking the link.

4. Flash reprogram the ABS Actuator Skid Control Computer.

A. Place the car in the "IG-ON" mode (push the Power button twice when the car is OFF - DO NOT depress the brake pedal).

B. Reflash the ABS Actuator Skid Control Computer with the newly designed software (New Calibration ID), following the procedures outlined in TSB No. T-SB-0064-10,"Techstream ECU Flash Reprogramming Procedure". Please refer to the Calibration Information table in this TSB for the NEW Calibration ID.

C. After completing the ABS Actuator Skid Control Computer reflash, disconnect the GR8 Battery Diagnostic Station or PSC Power Supply Charger / Maintainer (MTRPSC550SKT).

5. Using Techstream, check for Diagnostic Trouble Codes (DTCs).

NOTE

If any Pending, Current, and/or History DTCs are set, troubleshoot according to the Repair Manual.

6. Depress the brake pedal while vehicle is stopped to confirm the abnormal noise has been eliminated.