With Electronic Controls

^ Refer to the Symptom Table for the appropriate diagnostic procedure(s).

TECH 1 DIAGNOSIS
Vehicle Preparation
^ Connect a jumper from the Heater/Vent/Air Conditioning (HVAC) Control Head Connector, terminal "4" or terminal "5", to the DLC Connector, terminal "14." Insert the jumper through the back (wire entry side) of each connector.
^ Install the Tech 1 using the Body Systems Cartridge. When the Tech 1 asks for the model, key in 1990 (not 1996).
^ Proceed with climate control diagnosis

IMPORTANT: To prevent future data line communication problems, remove the jumper wire after diagnosis.