Control Assembly: Testing and Inspection

The control switch and timer circuit may be tested in the vehicle with or without scan tool (DRB).

Testing With Scan Tool
- If using the scan tool, refer to the proper Body Diagnostic Procedures.

Testing Without Scan Tool.

HVAC Control Module Connectors:

1. Remove the control switch from console and do not disconnect control switch.
2. Using a ohmmeter, check leads between Pins 5 and 8 of the 8-way connector. Depress the rear window defogger button and the resistance reading should be 500 to 520 ohms. If not OK, replace HVAC. If OK, check:
- Rear window relay (EBL)
- Blown fuse
- Cut wire
- Poor ground
- Poor connection
- Defective BCM
- Bulkhead connector inoperative

Switch Position = Ohm Range
Panel = 828 to 856 Ohms
Bi-Level = 1.279 to 1.315 K Ohms
Floor = 2.302 to 2.358 K Ohms
Mix = 5.202 to 5.318 K Ohms
Defrost = 99.5 to 101.5 K Ohms