Control Head Illumination/Display Does Not Operate Properly. Buick LeSabre 2005

For 1990-2009 cars only

Makes 🢒 Buick 🢒 2005 🢒 LeSabre 🢒 Vehicle Control Systems 🢒 Vehicle DTC Information 🢒 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 Diagnostic System Check - Vehicle?	Go to Step 2	Go to Diagnostic System Check - Vehicle in Vehicle DTC Information
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 (IPM) Special Functions. With a scan tool, observe the current DTC list in IPM. Does the scan tool display any DTCs?	Go to Diagnostic Trouble Code (DTC) List - Vehicle in Vehicle DTC Information	Go to Step 3
3	When performing the Diagnostic System Check, was DTC B2646 displayed for the IPM?	Go to Diagnostic System Check - Vehicle in Vehicle DTC Information	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 IPM Special Functions. Do all HVAC control module segments illuminate?	Go to Step 5	Go to Step 8
5	When performing the Display Test IPM command, do all other vacuum fluorescent (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 Control Module References in Computer/Integrating Systems for replacement, setup, and programming. 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