Electrical - Micro-Packs & Various Driveability Concerns

Number: 92-278-6E

Section: 6E

Date: SEPT. 1992

Corporate Bulletin No.: 276401

ASE No.: A1, A8

Subject:
VARIOUS DRIVEABILITY CONDITIONS

Model and Year:
1992 CAPRICE, CORSICA AND BERETTA
1992 C/K TRUCK AND G, L, M VANS

ENGINE APPLICATIONS:
2.3L (LGO), 3.1L (LHO), 4.3L (LB4, 5.0L (LO3), 5.7L (LO5)

ENGINE VIN (Models):
Car A, E, L, TZ, 7 Truck H, K, WZ

SUBJECT:
Micro-Pack Terminals causing Driveability Complaints

VEHICLE/TRUCK APPLICATIONS:
1992 Model Year B, L Cars
1992 Model Year C, K Trucks
1992 Model Year G, L, M Vans

CONDITION:
Some owners of the vehicles listed below may experience various driveability conditions such as reduced fuel economy, SES light, runs rough, misses, etc. (specific concerns are described in the following paragraphs). If diagnosis indicates a need to replace any control system components (example, ECM or sensors), check suspect connector terminals and repair if necessary prior to replacing the control system component.

CAUSE:
The condition may be a result of intermittent or open circuits caused by insufficient contact between the ECM harness female terminal and the mating ECM male pin. Some of the 12089649 micro-pack 100 series female terminals (formerly P/N 12020757) could have an oversized contact area condition.

NOTE:
Either terminal may be used in repair.








VIN BREAKPOINTS:
Suspect vehicle VIN breakpoints for PASSENGER CARS (see illustration).





Suspect vehicle VIN breakpoints for TRUCKS (see illustration).





SYMPTOMS (Passenger Car)











SYMPTOMS (Trucks)





CORRECTION:
1. To check for an oversize terminal, use a # 62* drill bit (.038 inches, .965 mm) and place a mark 1/2 inch up from the bottom of the shank of the drill bit. Place a flag made from tape at the mark on the drill (see Figure 1).
2. Remove connector from ECM and hold connector vertically up.





3. Place shank of # 62* drill bit (.038 inches, .965 mm) in connector cavity of suspect terminal. Do not push on drill (see Figure 2).
4. Repair any terminal allowing drill bit to fall unassisted to the flag on drill bit. Any terminals having resistance or drag or not allowing drill to enter terminal are okay and do not need repair. Repair any oversized terminal as described in steps 5 through 8.
5. Remove the TPA (terminal position assurance) from the connector.
6. Remove the terminal from the connector using terminal removal tool GM 12031876-1 (Kent-Moore Tool No. J 38125-A).








7. With a pair of small needle nose pliers, resize the contact area of the terminal as shown in Figure 3.
8. To verify the terminal has been adequately sized, insert a # 63* drill bit (.037 inches, .940 mm) into the contact area as shown in Figure 4. If resistance can be felt against the bit in the resized area, resizing is complete. If no resistance is felt, repeat steps 7 and 8.
9. Raise the terminal lock tang (Figure 4) so the terminal can be properly held in the connector.
10. Reinsert the terminal into the proper connector cavity.

11. Reinsert the TPA Into the connector.
12. If the terminal becomes severely damaged by using this method, replace the terminal using established terminal replacement procedures.
13. Reinstall harness to ECM and perform any required relearn procedure prior to continuing diagnosis.

* NOTICE:
Measure drill to ensure drill is of proper diameter. A larger sized drill will damage a good terminal.

WARRANTY INFORMATION:
Use applicable labor operation and time allowances.