ECM - Spark Knock/Die Out/Surge

NO.:
18-20-92

GROUP:
Driveability

DATE:
Nov.16, 1992



SUBJECT:
Spark Knock/Cold Engine Start Up Dieout/Engine RPM Surge At Light Throttle



MODELS:

1988-1991 (BB) Monaco/Premier

NOTE:
THIS BULLETIN APPLIES TO ALL 1988 - 1990 VEHICLES AND TO 1991 VEHICLES WITH A MDH PRIOR TO 1008XX.


SYMPTOM/CONDITION:

Vehicles may exhibit one or more of the following conditions:


1. With the engine fully warmed and the EGR system functioning the engine produces a sustained spark knock with a medium throttle application.


2. Cold engine driveway dieout after an overnight cold soak.


3. A harsh engine surge during a light load, light throttle to closed throttle transition.

This condition may be caused by the engine control module calibration.


DIAGNOSIS:

Before proceeding to the repair procedure, verify that all the systems are functioning as designed using the appropriate diagnostic test procedures.


PARTS REQUIRED:

1 Module, Engine Control 4728226
1 Label, Authorized Modification 4275086


REPAIR PROCEDURE:

This bulletin involves replacement of the Engine Control Module with a revised module.

1. Replace the Engine Control Module as described in the appropriate service manual.






2. Type the required information on the Authorized Modification Label, as show, and attach it near the VECI label.



POLICY:
Reimbursable within the provisions of the warranty.


TIME ALLOWANCE:
Labor Operation No. 08-15-62-95 ...........0.4 Hrs.


FAILURE CODE:
58 - Internal Defect