ROUGH RUN,SURGE,HARSH SHIFTS AND/OR PCM CODE P076

SUBJECT: ROUGH RUN, SURGE, HARSH SHIFTS AND/OR PCM CODE P076 (DIAGNOSE, REPLACE PCM)

VEHICLES AFFECTED: 1993 "E,K,V" MODELS

ENGINE (VIN) 9

Some 1993 Eldorados (before VIN breakpoint 608596), Sevilles (before VIN breakpoint 815363), and Allantes (before VIN breakpoint 127060) equipped with 4.6L Northstar engines may exhibit various driveability conditions caused by an injector driver or the transaxle pressure control solenoid in the PCM. Driveability conditions caused by an injector driver may include:

0 Rough running 0 Surge at steady speed

Driveability conditions caused by the transaxle pressure control solenoid driver may include:

0 PCM code P076 set 0 Harsh shifts

To determine if an injector driver in the PCM is the cause of one of these conditions, check the second digit of parameter PD17 during the ignition cycle when the condition occurred. If it is a "O", the injector driver in the PCM is not the cause. If it is a "l ", follow diagnostic chart 6C-3 "Injector Flow/Resistance Check" in Section 6C of the appropriate Service Information Manual.

To determine if the transaxle pressure control solenoid driver in the PCM is the cause of these conditions, follow the trouble tree for PCM code P076 in Section 6E-A of the appropriate Service Information Manual.

If the PCM is determined to be the cause, use the following chart to select the proper PCM service part number (the PCM service part number is on the PCM label):

Vehicle Service PCM P/N

1993 Allantes without RPO V4J 16159277 1993 Allantes with RPO V4J 16180517 1993 Eldorados and Sevilles with 4.6L Northstar 16180517

For vehicles repaired under warranty use:

Labour Operation: J6360 Labour Time: .06 HRS For PCM Replacement.

General Motors bulletins are intended for use by professional technicians, not a "do-it-yourselfer". They are written to inform those technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions and know-how to do a job properly and safely. If a condition is described, do not assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See a General Motors dealer servicing your brand of General Motors vehicle for information on whether your vehicle may benefit from the information.