EXPERTEC TSB (T88-28)

Publication date: 1987-09-21
Reference number: T88-28

EXPERTEC TSB

TECHNICAL SERVICE BULLETIN

Reference Number(s): T88-28, Date of Issue: 09/21/87

CODE 59/DRIVEABILITY COMPLAINT LOOSE ENGINE OR ECM GROUND

Model(s): 1985-87 Cadillac DeVille & Fleetwood

1986-87 Cadillac Eldorado & Seville

Bulletin No.: T88-28

Date: September 21, 1987

SERVICE INFORMATION

Some 1985-1987 DeVilles/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 DeVilles/Fleetwoods, the ECM ground connection (CKT450) is located at G101 on left front fender and the engine ground G1OO 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.

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 Fig 1 .

Fig 1: Revised Diagnostic Procedure For Step 2