ECU - Engine Knock Stall or Surge

91amcjeep01

SUBJECT: Spark Knock/Start and Stall/Engine Surge


NO.: 18-53-91


GROUP: DRIVEABILITY


DATE: Apr. 8, 1991


MODELS:

1988-91 (BB) PREMIER


NOTE: THIS BULLETIN APPLIES ONLY TO (BB) VEHICLES WITH V.I.N. PRIOR TO MH800000.

SYMPTOM/CONDITION:


Vehicle may exhibit sustained engine spark knock with medium throttle application, cold engine driveway dieout after an overnight cold soak, and/or an engine surge condition during a light load/light throttle situation (i.e. when speed control is activated).

DIAGNOSIS:


Using a DRB II tester and the appropriate diagnostic procedure manual, verify that all vehicle engine systems are functioning as designed (no fault codes are present). If all systems are functioning correctly, proceed with the following repair.

PARTS REQUIRED:

1 Electronic Control Unit (ECU) 4605097

1 Authorized Modification Label 4275086

REPAIR PROCEDURE:

This repair involves replacement of the original engine controller (ECU) with a revised one.

1. Turn the ignition switch to the OFF position and disconnect the battery.

2. Replace the engine controller with the unit as called out in PARTS REQUIRED.

3. Reconnect the vehicle battery.

Figure 1:

4. Type the required information on the Authorized Modification Label, as illustrated in Figure 1, and attach near the VECI label.


POLICY: Reimbursable within the provisions of the warranty.


TIME ALLOWANCE:
Labor Operation No. 08-15-62-94 . . . . . . . . . . . . . . . . . . 0.4 Hrs.

FAILURE CODE: AM - Authorized Modification


POLICY: Reimbursable within the provisions of the warranty.


TIME ALLOWANCE:
Labor Operation No. 09-45-01-90 . . . . . . . . . . . . . . . . . . . . 2.8 Hrs.

FAILURE CODE: 11 - Broken or Cracked