Control Head Illumination/Display Does Not Operate Properly. Buick LeSabre 2003

For 1990-2009 cars only

Makes 🢒 Buick 🢒 2003 🢒 LeSabre 🢒 HVAC 🢒 HVAC Systems - Automatic 🢒 Control Head Illumination/Display Does Not Operate Properly

Step	Action	Yes	No
Schematic Reference: HVAC Schematics Connector End View Reference: HVAC Connector End Views DEFINITION: Control head illumination/display does not operate properly.
1	Did you perform the HVAC Diagnostic System Check?	Go to Step 2	Go to Diagnostic System Check - HVAC Systems - Automatic
2	Install a scan tool. Turn ON the ignition, with the engine OFF. With a scan tool, perform the Recalibrate all Motors command in Instrument Panel Module Special Functions. With a scan tool, observe the current DTC list in Instrument Panel Module. Does the scan tool display any DTCs?	Go to Diagnostic Trouble Code (DTC) List	Go to Step 3
3	When performing the Diagnostic System Check, was DTC B2646 displayed for the Instrument Panel Module?	Go to Diagnostic Trouble Code (DTC) List in Lighting Systems	Go to Step 4
4	Install a scan tool. Turn ON the ignition, with the engine OFF. With a scan tool, perform the Display Test command in Instrument Panel Module Special Functions. Do all HVAC control module segments illuminate?	Go to Step 5	Go to Step 8
5	When performing the Display Test Instrument Panel Module command, do all other VF displays illuminate?	Go to Step 6	Go to Symptoms - Lighting Systems in Lighting Systems
6	Cover the sunload sensor assembly. Turn ON the lights. Is there backlighting?	Go to Step 7	Go to Symptoms - Lighting Systems in Lighting Systems
7	Adjust the dimming control from minimum intensity to maximum intensity. Does the VF display decrease and increase in intensity?	Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems	Go to Step 8
8	Inspect for poor connections at the harness connector of the HVAC control module. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition?	Go to Step 10	Go to Step 9
9	Replace the HVAC control module. Refer to HVAC Control Module Replacement . Did you complete the repair?	Go to Step 10	--
10	Operate the system in order to verify the repair. Did you correct the condition?	System OK	Go to Step 2