A/T - 1-2 or 2-3 Slip/Flare, Launch Shudder & DTC P1870

66-71-04
CHEVROLET

Issued: 05/10/96

SUBJECT:
AUTOMATIC TRANSMISSION 1-2 AND/OR 2-3 UPSHIFT SLIP/FLARE, NO 3RD OR 4TH GEAR, LAUNCH SHUDDER, DTC P1870 (REVISE VCM WIRING)

MODELS:
1996 CHEVROLET AND GMC C/K, S/T, M/L, G1, G2 AND P3 MODELS
1996 OLDSMOBILE BRAVADA
WITH VCM AND 4L60-E (M30) OR 4L80-E (M11)
AUTOMATIC TRANSMISSION

CONDITION:
SOME OWNERS MAY COMMENT THAT THE AUTOMATIC TRANSMISSION HAS EITHER A SLIP OR FLARE ON THE 1-2 AND/OR 2-3 UPSHIFT, OR NO 3RD OR 4TH GEAR, OR LAUNCH SHUDDER. DTC P1870 MAY ALSO BE STORED IN THE VCM.

CAUSE:
A POOR INTERNAL GROUND BETWEEN THE TWO CIRCUIT BOARDS OF THE VCM CAN CAUSE THE VCM TO COMMAND ERRATIC LINE PRESSURE AT THE PRESSURE CONTROL SOLENOIDS (PCS).

CORRECTION:
USING HARNESS JUMPER WIRE AND INSTRUCTION KIT, P/N 12167310, REVISE THE WIRING HARNESS AT THE VCM CONNECTOR.
CORRECTIONS WERE MADE TO THE VCM BEGINNING 2/14/96. THE CORRECTED VCM'S ARE IDENTIFIED WITH SERVICE NUMBER 16244210 ON THE VCM IDENTIFICATION LABEL.

SERVICE PROCEDURE

THE FOLLOWING IS A SUMMARY OF THE INSTRUCTIONS INCLUDED WITH THE SERVICE KIT:

1. REMOVE THE NEGATIVE TERMINAL FROM THE BATTERY.

2. MOVE THE WIRE LOCATED AT CONNECTOR J3 (WHITE/GRAY/CLEAR), PIN 18 TO CONNECTOR J1 (BLUE), PIN 23.

3. INSTALL THE JUMPER WIRE BETWEEN CONNECTOR J2 (RED), PIN 26 AND CONNECTOR J3 (WHITE/GREY/CLEAR), PIN 18.

4. INSTALL THE TAG INCLUDED IN THE KIT AROUND THE VCM WIRING HARNESS. THIS TAG NOTES THAT THE WIRING HARNESS HAS BEEN MODIFIED.

5. RECONNECT THE NEGATIVE BATTERY TERMINAL.

ROAD TEST TO VERIFY THAT THE CONDITION HAS BEEN CORRECTED.
IF ANY OF THE FOLLOWING CONDITIONS ARE NOTED, THE TRANSMISSION SHOULD BE REPLACED, OR FOR CANADIAN DEALERS, REPAIRED.

- TRANSMISSION FLUID OXIDATION OR EXCESSIVE SEDIMENT.
- TRANSMISSION SLIP OR FLARE AFTER THIS SERVICE FIX IS PERFORMED.
- DTC P1870 IS STORED ON A 4L60-E (M30).

THE FOLLOWING TOOLS ARE AVAILABLE FROM KENT-MOORE (1-800-345-2233) FOR USE IN REMOVING AND RELATING THE VCM CONNECTOR.

- J41759 PUNCH: USED TO PUNCH A NEW HOLE THROUGH THE CONNECTOR SEAL.

PARTS INFORMATION

P/N DESCRIPTION QTY

12167310 HARNESS JUMPER WIRE KIT 1

PARTS ARE EXPECTED TO BE AVAILABLE ON 5/13/96 FROM GMSPO.

WARRANTY INFORMATION

FOR VEHICLES REPAIRED UNDER WARRANTY, USE:

LABOR OP DESCRIPTION LABOR TIME

N6112 WIRE REPAIR USE PUBLISHED
FRONT CHASSIS LABOR OPERATION
TIME