Some 2008 – 2011 model year LX 570 vehicles may exhibit a MIL “ON” condition with transmission performance DTCs such as P2714, P0751, P0756, P0761, P0766, P0729, P0781, P0894, P2757, or P0776 and/or abnormal transmission shifting. Revised Engine Control Module/ECM (SAE term:Powertrain Control Module/PCM) software logic has been developed to address this condition. Insome cases, replacement of the automatic transmission may also be required.
NOTE
Confirm correct transmission fluid level by following the procedures in the Repair Manual BEFOREordering parts or reprogramming the ECM (PCM) since incorrect fluid level can also cause these DTCs.
APPLICABLE WARRANTY
- This repair is covered under the Lexus Federal Emission Warranty. This warranty is in effect for 96 months or 80,000 miles, whichever occurs first, from the vehicles in-service date.
Parts Information:
NOTE
- The ECM (PCM) should NOT be replaced as part of the repair procedure.
Repair Procedure
1.Using Techstream, save Freeze Frame data, clear DTCs (if set), and perform a test drive.
Does the MIL “ON” reoccur with transmission performance DTCs resetting?
NOTE
Most transmission performance DTCs are two-trip detection logic DTCs.
Does the transmission display any transmission shifting issues?
- YES to A or B — Go to step 2.
- NO to A and B — Continue test driving the vehicle and try to duplicate the MIL “ON” orabnormal transmission shifting. If unable to duplicate complaint, return the vehicle tothe customer. Do NOT attempt to repair the vehicle.
2.Check the transmission for evidence of leakage, and address as necessary.
3.Check the transmission fluid level.
Refer to the Technical Information System (TIS), applicable model and model year Repair
Manual:
- 2008 / 2009 / 2010 / 2011 LX 570:
Drivetrain – Automatic Transmission/Transaxle – “AB60F Automatic Transmission/Transaxle:Automatic Transmission Fluid: Adjustment”
NOTE
Incorrectly adjusted fluid level can cause transmission shifting issues and MIL “ON” conditions.
Is the transmission fluid level correct?
- YES — Go to step 4.
- NO — Adjust fluid level to correct level, then repeat step 3 to confirm correct fluid level.
Does the transmission fluid smell burnt or have a gritty feel from contamination?
NOTE
It is normal for WS transmission fluid to change from a clear red color when new to an opaque brown color with use.
- YES — Reprogram the ECM (PCM) per steps 5 – 6, then replace the transmission assembly per step 8.
- NO — Go to step 5.
5.Flash reprogram the ECM (PCM).
Check for the Authorized Modifications Label affixed to the vehicle in the location. Confirm if the ECM (PCM) calibration has been updated. If the calibration ID listed is NOT the latest ECM (PCM) calibration, go to step B.
Flash reprogram the ECM (PCM).
NOTE
- The GR8 Battery Diagnostic Station MUST be used in Power Supply Mode to maintain battery voltage at 13.5 volts while flash reprogramming the vehicle.
6.Install the Authorized Modifications Label.
A.Using a permanent marker, enter the following information on the label:
- ECM part number [Refer to the Parts Information section for the CURRENT PART NUMBER]
- Calibration ID(s) [Refer to the Calibration Identification Chart for the NEWCALIBRATION ID]
- Dealer Code
- Repair Date
- Change Authority [This bulletin number]
B.Affix the Authorized Modifications Label to the vehicle at the location.
The Authorized Modifications Label is available through the MDC, P/N 00451-00001-LBL.
7.Test drive the vehicle and perform transmission initialization.
Refer to TIS, applicable model and model year Repair Manual:
- 2008 / 2009 / 2010 / 2011 LX 570:
Drivetrain – Automatic Transmission/Transaxle – “AB60F Automatic Transmission/Transaxle:
Automatic Transmission System: Initialization”
Does the MIL “ON” reoccur with transmission performance DTCs resetting?
NOTE
Most transmission performance DTCs are two-trip detection logic DTCs.
Does the transmission display any transmission shifting issues?
- YES to A or B — Go to step 8.
- NO to A and B — Continue test driving the vehicle and try to duplicate the MIL “ON” or abnormal transmission shifting. If unable to duplicate complaint after ECM (PCM) reprogramming, the repair is complete.
8.Replace the transmission assembly.
9.Confirm the repair.