Note On INTERMITTENTS

If an intermittent Code B120 is being set, check B120 snap data value for twilight delay BD43 display. If BD43 display value is greater than 98 percent, code resulted from an open in circuit No. 736 or left switch pod. If BD43 display value is less than 2 percent, code resulted from a short in left switch pod or circuit No. 271. Manipulate related wiring while observing BCM data parameter BD43 display. If failure is induced, reading will jump from its normal value to a reading outside range of 2-98 percent.

Fig 1: Code B120, Schematic, Twilight Delay Potentiometer Ckt

Courtesy of GENERAL MOTORS CORP.

Fig 2: Code B120, Flow Chart, Twilight Delay Potentiometer Ckt

Courtesy of GENERAL MOTORS CORP.