The 1988-92 TECH 1 transmission cartridge has two software conditions that may not allow correct diagnosis of the affected vehicle systems.
#1 - 1992 trucks with 5.7L TBI (L05) engines and HYDRA-MATIC 4L80-E transmissions (GVW greater than or equal to 8600 lbs) will display incorrect transmission temperature.
#2 - 1992 trucks with 6.2L Diesel (LL4) engines and HYDRA-MATIC 4L80-E transmissions are not included in the cartridge under the 1992 model year select options.
-------- Mis-programmed 1992 TECH 1 cartridge.
#1 - Select a 1992 7.4 L TBI (L19) system with GVW greater than or equal to 8600 lbs. This will correctly display all data parameters including transmission temperature for
#2 - Select a 1991 6.2 Diesel (LL4) on the model year select screen. This will properly function for diagnosis of the 1992 application.
1988-92 TECH 1 transmission cartridges will be shipped to dealers with a label and a TECH 1 operators manual insert page to alert the user to the above conditions.
General Motors bulletins are intended for use by professional technicians, not a "do-it-yourselfer". They are written to inform those technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions and know-how to do a job properly and safely. If a condition is described, do not assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See a General Motors dealer servicing your brand of General Motors vehicle for information on whether your vehicle may benefit from the information.