Digital Cluster - Engine Electrical Related Conditions
Bulletin 86-8-5ADate May '86
Ref.No. 86-040A-8
SUBJECT: DIGITAL CLUSTER ENGINE ELECTRICAL RELATED CONDITIONS
MODELS AFFECTED: 1985 SOMERSET, 1986 SKYLARK, AND 1986 SOMERSET WITH 2.5L ENGINE (VIN CODE U)
NOTE: THIS BULLETIN SUPERSEDES BULLETIN 86-8-5, DATED JAN., '85. THE PART NUMBER IN ORIGINAL BULLETIN WAS INCORRECT, PLEASE DISCARD ORIGINAL BULLETIN AND REPLACE IT WITH THIS ONE.
Some 2.5L equipped Buick "N" cars may exhibit digital cluster conditions that are engine electrical related. Before requesting an exchange cluster be sure to check for the following conditions:
The tachometer filter, taped to the engine harness by the ignition coil, may become inoperative when the car is cold and then work normally 5 to 10 minutes after the engine is started. During the inoperative period the display can be affected in two ways:
1. The speedometer "pegs" at 85 mph and flashes and the multi-function gauges may flash.
2. The tachometer reads 3 to 4 times the actual ERPM value.
If either of these conditions occur, replace the tachometer filter (P/N 10035324).
The ignition coil may become inoperative. If the digital cluster segments flash in a random manner with the engine running and operates correctly with the engine not running, replace the ignition coil (P/N 1115315).
Be sure to follow other diagnostic procedures outlined in the Chassis Service Manual before replacing the digital cluster.