Canada - Engine/Engine Controls - Engine Idle Knock Noise
BulletinTSB2445
Issue Date
July 17, 2007
Title
ENGINE IDLE KNOCK NOISE
Component
ENGINE MECHANICAL
Models
'07 LS 460/460L
INTRODUCTION:
Some 2007 model year LS 460 vehicles may exhibit a knocking noise originating from the engine compartment that is most noticeable under the following conditions:
- Engine idling at operating temperature
- A/C OFF
- A/T in "D" range
The Engine Control Module (ECM) (SAE term: Powertrain Control Module/PCM) logic, valve lash adjusters, and the No. 3 timing chain tensioner have been modified to improve this condition. Please use the repair procedure below to address customer concerns.
APPLICABLE VEHICLES:
- 2007 model year LS 460/460L vehicles produced BEFORE the Production Change Effective VINs shown below.
PRODUCTION CHANGE INFORMATION:
WARRANTY INFORMATION:
PARTS INFORMATION:
CALIBRATION IDENTIFICATION CHART:
REQUIRED SSTs:
REPAIR PROCEDURE:
Determine the ECM (PCM) calibration ID for the vehicle.
- If calibration ID 35036000 (previous calibration ID) is present - go to Repair Procedure A.
- If calibration ID 35036100 (NEW calibration ID) is present - go to Repair Procedure B.
REPAIR PROCEDURE A:
1. Check for the Authorized Modifications Label affixed to the vehicle in the location shown in Figure 1. Confirm if the ECM (PCM) calibrations have been updated.
If the calibration IDs are NOT the latest calibrations - go to step 2.
If the calibration ID listed is the latest ECM (PCM) calibration - go to Repair Procedure B.
2. Flash Reprogram the ECM (PCM).
NOTE:
The Midtronics Battery charger MUST be used in Power Supply Mode to maintain battery voltage at 13.5 volts while flash programming the vehicle.
Follow the procedures outlined in TSB2758 "Techstream ECU Flash Reprogramming Procedure," and flash the ECM (PCM) with the NEW calibration file update.
3. Install the Authorized Modifications Label.
A. Using a permanent marker, enter the following information on the label:
- ECM (PCM) part number: [Refer to the Parts Information section for the CURRENT PART NUMBER]
- Calibration ID(s): [Refer to the Calibration Identification Chart for the NEW CALIBRATION ID]
- Dealer Code
- Repair Date
- Change Authority (this TSB number): 2445
B. Affix the Authorized Modifications Label to the vehicle at the location shown in Figure 1. The Authorized Modifications Label is available through the MDC, P/N 00451-00001-25.
4. Confirm that the ECM recalibration addressed the customer concern. If the knocking noise is gone, the repair is complete. If the noise is still present, go to Repair Procedure B.
REPAIR PROCEDURE B:
1. Replace the No. 3 timing chain tensioner and both No. 1 cylinder intake valve lash adjusters.
Refer to the Repair Manual within E-TAS / TIS library:
- Division: Lexus
- Model: LS 460
- Year: 2007
- Service Category: Engine/Hybrid System
- Section: Engine Mechanical
- Keyword: 1UR-FSE Engine Mechanical: Camshaft (for Bank 1): Removal
- Keyword: 1UR-FSE Engine Mechanical: Camshaft (for Bank 1): Installation
2. Reconnect the negative (-) battery terminal.
3. Re-initialize any affected power systems.
4. Test drive the vehicle to confirm that the knocking noise is NO longer present.
NOTE:
Issue of this Technical Service Bulletin is to ensure that proper repair information is available. IT DOES NOT CONSTITUTE AN AUTHORIZATION FOR REPAIR. Normal provisions of the formal warranty policy, as applicable, will apply.