Intermittent MIL Flickering, Poor Driveability, No DTC's

90cadillac07
Bulletin No. T-90-64
File in Group 6E
Number 79
Corp. Ref. No. 016515
Date April, 1990



SUBJECT: INTERMITTENT FLICKERING CHECK ENGINE LIGHT, POOR DRIVEABILITY, NO CODES STORED

MODELS AFFECTED: 1986-1990 BROUGHAMS WITH 5.0L ENGINE (VIN CODE Y)


Some 1986-1990 Broughams equipped with 5.0L engine may experience an intermittent flickering check engine light, accompanied by an unstable idle, miss, or rough running engine, with no codes stored. This condition may be caused by a momentary internal open in the distributor pole piece/pick-tip coil.

To repair this condition, use the following procedure:

1. Check ECM power circuits 480 and 439 for opens.

2. Check ECM ground circuit 450 for open.

3. 1988-1990 models, go to step 5.

4. On 1986 and 1987 models perform ECM replacement check, chart C1 in Section 6E1-C1, if passes ECM replacement check go to step 5.

5. Replace distributor pole piece/pick-up coil. Refer to Section 6D of the appropriate Service Information Manual.