ECU - Engine Performance/Sag/Surge On Acceleration

91amcjeep05

NO.: 18-56-91

GROUP: ELECTRICAL

DATE: Sept. 9, 1991


SUBJECT: Cold Engine Poor Performance/Sag Or Surge On Acceleration


MODELS:

1991-92 (BB) PREMIER EQUIPPED WITH SINGLE BOARD ENGINE CONTROLLER (SBEC II)

(1991 vehicles built after MDH 10-08-XX are equipped with a SBEC II. These vehicles can be identified by an eight in the twelfth position of the VIN.)


SYMPTOM/CONDITION:

The vehicle will exhibit the two following conditions. First, the engine will sag and/or popback during the first aggressive throttle tip in. This will happen within the first ten seconds of a cold engine start up when the ambient temperature is between approximately 60~F - 90~F (15~C - 32~C). Second, with the engine fully warm, the vehicle will exhibit a surge while traveling 30-40 MPH (50-65 KM/H).


DIAGNOSIS:

Verify that the system is functioning as designed using the appropriate diagnostic test procedure.


PARTS REQUIRED:

1 Engine Controller 4605101

1 Authorized Modification Label 4275086


REPAIR PROCEDURE:

This procedure involves replacement of the engine controller (SBEC) with a revised engine controller.

1. Following the service manual procedure, replace the original engine controller with the revised engine controller (4605101).

Figure 1:

Type an authorized modification label, PN 4275086 as shown in Figure 1 and attached near the VECI label.


*INSERT PART NUMBER USED.


POLICY: Reimbursable within the provisions of the warranty.


TIME ALLOWANCE:
Labor Operation No. 08-19-91-90 . . . . . . . . . . . . . . . . . . . 0.4 Hrs.


FAILURE CODE: AM - Authorized Modification