This bulletin applies to 2015-2016 Corvette models equipped with an 8L90 transmission. The customer may comment on firm garage shifts, Park to Drive or Park to Reverse, after the vehicle has been sitting for several hours with the engine off, and/or a clunk noise that occurs as the engine starts or immediately after the engine starts, along with an illuminated MIL. DTC P16F3 may be found as an active or history DTC.
A revised calibration has been developed to address these concerns. Update the transmission control module (TCM) using the Service Programming System (SPS) with the latest software available on TIS2WEB.
Verify that the battery voltage is more than 12 volts but less than 16 volts before reprogramming. The battery must be fully charged before reprogramming. During programming, battery voltage must be maintained within 12-15.5 volts.
Connect the approved Midtronics PSC 550 Battery Maintainer to the vehicle or the GR8 in the power supply mode. After updating the TCM, complete the K71 transmission control module setup, with setup to run the Service Fast Learn procedure. At the end of programming, choose the “Clear All DTCs” selection on the scan tool.