Exhaust System - Excessive Sulfur Dioxide Odors
ENGINEEG004-04
Title:
EXCESSIVE SULFUR DIOXIDE ODOR
Models
'03 - '04 GX 470
April 26, 2004
Introduction
Some customers may complain of excessive sulfur dioxide odor on 2003-2004 model year GX 470 vehicles under the following conditions:
^ Stop and go driving.
^ Heavy acceleration.
In order to reduce the sulfur dioxide odor, the Electronic Control Module (ECM) (SAE term: Powertrain Control Module/PCM) fuel cut control logic has been modified and a new catalyst is provided. Follow the repair procedure to reflash the ECM and replace the catalytic converter assembly.
NOTE:
For more complete understanding of the root cause, refer to TSIB No. EG001-03
"Sulfur Odor From Exhaust," dated February 24, 2003.
Applicable Vehicles
^ 2003 - 2004 model year GX 470 produced BEFORE the Production Change
^ Vehicles Effective VIN shown below.
Production Change Information
Warranty Information
Applicable Warranty*:
This repair is covered under the Lexus Specified Major Emission Control Component 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
NOTE:
Authorized Modification Labels may be ordered in packages of 25 from the Materials Distribution Center (MDC) through Dealer Daily or by calling the MDC.
Required SSTs
NOTE:
Additional Diagnostic Tester Kits, Program Cards or other SSTs may be ordered by calling SPX/OTC at 1-800-933-8335.
ECM (PCM) Identification Chart
NOTE:
2004 model year Sub Calibration ID will display YES as DONE on the Diagnostic Tester display.
ECM Reprogram Procedure
1. Check for the Authorized Modification Label affixed to the vehicle in the location shown in Figure 2. If there is no label present, proceed to step 2.
2. Connect the Diagnostic Tester to the vehicle and select ~CURRENT ECU CAL" from the ECU REPROGRAM MAIN MENU." To determine the vehicle's current ECM calibration, see Figure 1 shown.
3. Proceed to Flash Reprogram the ECM (PCM) by following the procedures in TSIB No. SS001-01 titled "ECU Flash Reprogramming Process," for 2001 and later applicable models.
NOTE:
Errors during the flash reprogramming process can PERMANENTLY DAMAGE the vehicle's ECM (PCM). In order to minimize this risk follow the steps below:
^ Make sure that the current battery voltage is no less than 11.4 volts.
^ Install a battery charger and set on a low setting to assure that the battery voltage DOES NOT FALL BELOW 11.4 VOLTS during the reprogramming.
^ If battery's state of charge is in question, test with SST No. 00002-MP815-L, "Midtronics Battery Tester."
^ Confirm that the engine hood is up, parking brake is set and all accessories are OFF (i.e., audio system, A/C, interior lights, headlights, etc).
^ DO NOT perform the reprogramming process until the engine room temperature is 158°F or less.
^ Confirm cable connections between the vehicle and the Diagnostic Tester are secured.
^ In case of Error Message "Cannot Go To Reprogram Mode," refer to TSIB No. SS003-O1 "ECU Flash Reprogramming Error Message."
^ Do not interrupt the vehicle during the reprogramming process, keep all doors closed.
4. Select the proper ECM (PCM) calibration file for the model year vehicle and reprogram the ECM (PCM).
5. Start the engine and warm up the vehicle to normal operating temperatures before test-driving.
6. Test drive vehicle to confirm proper operation and to readjust the ECM (PCM) "Learned Values." Drive the vehicle using light to moderate acceleration in mostly stop and go type driving. Allow the vehicle to shift fully through all gears and at various shifter positions (D, 4, 3, 2, 1).
7. Enter the following information on the Authorized Modification Label shown in Figure 2 using a permanent marker.
^ ECM (PCM) part number.
^ New ECM (PCM) calibration number.
^ Your dealer code.
^ Reprogramming date.
^ This TSIB number.
Catalytic Converter Replacement Procedure
1. Refer to the Technical Information System (TIS) 2003 or 2004 model year GX 470 Repair Manual: Exhaust.