Engine Control - Intermittent or Hard Code E59/E059
87cad6Bulletin No. T 88-28
File in Group 6E
Number 53
Corp. Ref. No. 716509
Date Sept. '87
SUBJECT: CODE E59 OR E059
MODELS AFFECTED: 1985-1987 DE VILLE/FLEETWOOD 1986-1987 ELDORADO AND SEVILLE
Some 1985-1987 De Villes/Fleetwoods or 1986-1987 Eldorados and Sevilles may experience an intermittent or hard Code E59 or E059. This ECM Code may be accompanied by any one or more of the following symptoms:
^ Engine may stop running at idle when accessory loads are applied.
^ Engine miss or backfires.
^ Intermittent engine won't crank.
The ECM Code E59 or E059 may be caused by a loose/poor ECM ground (CKT450) or engine ground connection.
On 1985-1987 De Villes/Fleetwoods, the ECM ground connection (CKT450) is located at G101 on left front fender and the engine ground G100 is located at lower front of engine near starter motor.
On 1986-1987 Eldorados and Sevilles, the ECM ground connection (CKT450) is located at G100 at right front engine compartment ahead of battery, and engine ground G103 is located at lower front of engine near starter motor.
To repair this condition, clean and tighten loose/poor ground connection to the stud with a star washer and nut.
Figure 1:
The following revised diagnostic procedure for step 2 only in trouble code E59 or E059 should be used for all 1986-1987 De Villes/Fleetwoods, Eldorados and Sevilles in place of Step 2 listed in the Final Edition Service Information Manuals (see Figure 1).
For warranty purposes, use Labor Operation T6240 at .2 hour.