EXPERTEC TSB (92-24-6E)

Publication date: 1991-10-25
Reference number: 92-24-6E

EXPERTEC TSB

TECHNICAL SERVICE BULLETIN

Reference Number(s): 92-24-6E, Date of Issue: 10/25/91

SHUDDER OR VIBRATION AT LOW SPEEDS (NEW PROM RELEASED)

Model(s): 1990-92 LUMINA (APV) WITH 3.1L ENGINE

Section: 6E2-B-3

Bulletin No.: Chevrolet 92-24-6E

Date: 10/25/1991

VEHICLES AFFECTED

Vehicles with 3.1L (VIN D) engine.

SERVICE INFORMATION

THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN 91-380-6E. THE 1992 MODEL YEARS HAS BEEN ADDED. ALL COPIES OF 91-38O-6E SHOULD BE DISCARDED.

CONDITION

Some owners of 1990 - 1992 U-vans with 3.1 L (VIN D) engine may comment of a Shudder or Vibration at low speeds.

CAUSE

This condition may be caused by the transmission converter clutch being engaged at 23 MPH.

CORRECTION

If normal diagnostic procedures shown in your Service Manual (Section 6E2-B-3) do not correct this condition, a new PROM with a "TCC" (torque converter clutch) engagement speed of 35 MPH is available. The part numbers are as follows:

VEHICLE PROM PACKAGE PART NUMBER

Year	Emission system	Scanner I.D.	Broadcast Code
1990	California	3431	AYAC
1990	Federal	3441	AYAD
1991 - 1992	California	4911	AYHP
1991 - 1992	Federal	4901	AYHN

NOTE: This correction will have no impact on performance above 35 MPH. Parts are currently available from GMSPO.

LABOR INFORMATION

Labor Operation Number: T0500

Labor Time : .7 hours