Engine Controls - Engine Knocking Or Pinging Noises

T-SB-0125-08

Rev1

July 2, 2008

Engine "Pinging" or "Knocking" Noise

Service Category
Engine/Hybrid System

Section
Engine Control

Market
USA





Applicability

TSB REVISION NOTICE
- November 17, 2008 Rev1:
- Applicability has been updated to include 2003 model year.
- Warranty and Parts Information sections have been updated with 2003 model year information.

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

Introduction

Some 2001 - 2003 model year Sienna 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





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.