Engine Controls - Pinging/Knocking Climbing Grades

T-SB-0017-08

Rev1

March 12, 2008

Engine "Pinging" or "Knocking" Noise

Service Category
Engine/Hybrid System

Section
Engine Control

Market
USA





Applicability

TSB REVISION NOTICE

^ June 18, 2008 Rev1:

^ Applicability has been updated to include 2001 and 2002 model years.

^ Parts Information has been updated with part numbers for 2001 and 2002 model years.

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

Introduction

Some 2001 - 2003 model year Highlander 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 improved to address this condition.





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.