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Home >> Buick >> 1991 >> Reatta 2D Convertible >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Tests W/Codes - Pcm/BCM >> BCM Trouble Code Charts >> Code B123, Courtesy Lamp Switch Circuit >> Note On Intermittents
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Note On Intermittents

If circuit No. 685 were intermittently grounded, Code B123 could be stored. Manipulate circuit No. 685 while observing BI01 display with dimmer at a low setting. If short occurs, value will switch from HI to LO.

Also check BD42 display. Cycle panel dimming control from minimum to maximum. If BD42 display does not range between 2 and 98 percent, or never reads more than 75 percent, replace left switch assembly.

Fig 1: Code B123, Schematic, Courtesy Lamp Switch Circuit
G91F07773
Fig 2: Flow Chart, Code B123, Courtesy Lamp Switch Circuit
GB0022639