Control Switch and Timer Test

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.

HVAC Control Module Connectors:

TESTING WITHOUT SCAN TOOL
1. Remove the control switch from console and disconnect control switch.
2. Using a ohmmeter, check leads between Pins 5 and 8 of the 8-Way connector. Turn the control module to each position shown on the Control Module Test Chart below. The resistance reading should be within the specifications shown. If not OK, replace the control module. If OK, check:
- Blown fuse
- Cut wire
- Poor ground
- Poor connection
- Defective BCM
- Bulkhead connector inoperative

CONTROL MODULE TEST CHART

SWITCH POSITION OHM RANGE

Defogger switch ON 499 - 520 ohms
Panel 828 - 856 ohms
Bi-Level 1.279 - 1.315 Kohms
Floor 2.302 - 2.358 Kohms
Mix 5.202 - 5.318 Kohms
Defrost 99.5 - 101.5 Kohms