2006 Cadillac STS-V: Service Bulletin: #06-06-04-053: LC3 Engine MIL/SES, DTCs P0128, P0171, P0174 or P2261 (Reprogram ECM)

#06-06-04-053: LC3 Engine MIL/SES, DTCs P0128, P0171, P0174 or P2261 (Reprogram ECM) - (Oct 16, 2006)

Subject:	LC3 Engine MIL/SES, DTCs P0128, P0171, P0174 or P2261 (Reprogram ECM)
Models:	2006 Cadillac STS-V, XLR-V
	with Supercharged 4.4L Northstar® DOHC V8 SC Engine (VIN D — RPO LC3)

Condition

Some customers may comment on an illumination of the SES/MIL with no other symptoms. Upon further investigation, the technician may find one or more of the following DTCs stored in the ECM:

DTC P0128: Engine Coolant Temperature (ECT) Below Thermostat Regulating Temperature
DTC P0171: Fuel Trim System Lean Bank 1
DTC P0174: Fuel Trim System Lean Bank 2
DTC P2261: Supercharger By-Pass Valve Stuck

Cause: This condition may be caused by a calibration issue that causes DTCs to set when no fault is present.

Correction

If routine diagnosis using SI does not reveal any obvious cause for the DTCs setting, reprogram the ECM.

Reprogram the ECM with the latest calibrations if the above concern is encountered. An updated ECM calibration is now available to address this concern. This calibration, or any that follow, is designed to address this concern. Refer to Service Programming System (SPS) using the appropriate Service Information (SI) procedures. The new ECM calibrations will be available to dealerships in TIS2Web (website version of TIS) version 10.5 for 2006 beginning 10/15/2006. If you cannot access the calibration, call the Techline Customer Support Center at 1-800-828-6860 (English) or 1-800-503-3222 (French) and it will be provided. As always, make sure your Tech 2® is updated with the latest software version.