GM recommends that because so many of the control operations are electronic, special diagnostic equipment really should be used for system diagnostics and check-out. An authorized technician using a scan tool can most quickly locate HVAC problems. GM recommends that the heater & A/C control panel be replaced only if specific diagnostic procedures points to the control panel as the only possible source of faults. Even then, the control panel does not automatically need to be replaced if a short is found in the wiring. Repair the wiring first, then check the system for further concerns. Most system malfunctions are traceable to faulty wiring and connectors, and occasionally, components. GM claims the heater & A/C control panel is very reliable and usually not the cause of a system malfunction. A heater & A/C control panel replacement before a complete and thorough diagnosis will usually result in a recurrence of the original complaint.
- Disconnect the negative battery cable.
Remove the instrument cluster trim plate, using the following as a guide:
- Remove the instrument panel access hole covers from the instrument panel using a small flat-bladed tool. Remove the screws from each end of the instrument panel cluster trim plate.
- Remove the screws from the lower edge of the right lower instrument panel trim plate.
- Open the instrument panel compartment door.
- Pull the right lower instrument panel trim plate from the instrument panel.
- Pull steering column tilt level and tilt the steering column to the lowest position.
- Grasp the instrument panel cluster trim plate at the right edge, slowly pull an working from left to right, release the retainer clips. Lift the trim panel from the vehicle.
- Remove the screws holding the heater & A/C control panel to the instrument panel and gently pull the assembly from the instrument panel. Detach the electrical connector(s) from the back of the panel. Some models may have a vacuum line connection that must also be removed.
- Installation is the reverse of the removal process. Use care to make sure the retaining clips are properly seated and all screws are in place. This helps avoid rattles and squeaks later.