Engine Controls - Knock Or Ping Accelerating On A Grade

T-SB-0124-08

Rev1

July 2, 2008

Engine "Pinging" or "Knocking" Noise

Service Category
Engine/Hybrid System

Section
Engine Control

Market
USA





Applicability

TSB REVISION NOTICE

^ February 20, 2009 Rev1:

^ Applicability has been updated to include 2003 and 2004 model years.

^ Warranty and Parts Information sections have been updated with 2003 and 2004 model year information.

^ A Note has been added to step 1 of the Repair Procedure.

Any previous printed versions of this service bulletin should be discarded.

Introduction

Some 2000 - 2004 model year Avalon vehicles equipped with a 1MZ-FE engine may exhibit an intermittent "pinging" or "knocking" noise when accelerating slowly up a grade. The Engine Control Module (ECM) (SAE term: Powertrain Control Module/PCM) logic has been modified to improve this condition. Use the following procedure to address customer concerns.





Warranty Information

APPLICABLE WARRANTY

^ This repair is covered under the Toyota Federal Emission Warranty. This warranty is in effect for 96 months or 80,000 miles, whichever occurs first, from the vehicle's in-service date.

^ Warranty application is limited to correction of a problem based upon a customer's specific complaint.





Parts Information

Inspection Procedure

1. Drive the vehicle slowly up a slight grade using light throttle input.

2. If engine "pinging" or "knocking" can be heard between 1400 - 1800 rpm, follow the procedure below to resolve the customer's concern.

Repair Procedure








1. Remove and replace the ECM (PCM).

2. Start the engine and warm it up to normal operating temperature before test driving.

3. Test drive the vehicle to confirm normal operation. The repair is complete.