Owners of 2007 Isuzu Ascender models may come into your store with a complaint that their a/c system blows warm air. The air conditioning woes may be accompanied by an illuminated check engine light, with trouble code P0116 (engine coolant temperature sensor performance) logged in PCM memory.
One likely cause of the trouble, Isuzu said, is software anomalies in the PCM. Those anomalies cause the P0116 code to set. And while the code is active, the module won't allow the a/c compressor to engage, which leads to the warm air complaint from the customer. Reprogramming the PCM with updated software is the only solution.
Check with a dealer for the application specifics of the flash.
"Factory Fixes" is written by Jim DePalma, a 30-year veteran of the auto repair business who has served stints as a service manager, parts manager and ASE-certified technician. His column provides vehicle manufacturers' authentic factory technical service bulletins (TSBs) that have been condensed for easier reading. Mr. DePalma advises that techs always check with a dealer or repair information system for the latest revisions before starting to work on a vehicle. He can be reached via email at [email protected].