Engine & A/T - Rough, Surge, Harsh Shift, or DTC PO76
Bulletin No.:93-63
File in Group:
6E
Number:
7
Corp.Ref.No.:
316002
Date:
Feb. 1993
SUBJECT:
ROUGH RUN, SURGE, HARSH SHIFTS, AND/OR PCM CODE P076 CAUSED BY AN INJECTOR DRIVER OR THE TRANSAXLE PRESSURE CONTROL SOLENOID DRIVER IN THE PCM
MODELS AFFECTED:
1993 ELDORADOS EQUIPPED WITH 4.6L NORTHSTAR ENGINE (VIN CODES Y AND 9) BEFORE VIN BREAKPOINT 608596; SEVILLES EQUIPPED WITH 4.6L NORTHSTAR (VIN CODE 9) BEFORE VIN BREAKPOINT 815363; AND BEFORE VIN BREAKPOINT 127060
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 driver in the PCM. Driveability conditions caused by an injector driver may include:
^ Rough running
^ Surge at steady speed
Driveability conditions caused by the transaxle pressure control solenoid drawer may include:
^ PCM code P076 set
^ 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 "0", the injector driver in the PCM is not the cause. If it is a "1", 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
Parts are currently available from GMSPO.
For warranty purposes use Labor Operation J6360 at .6 hour for PCM replacement.