4L60EHarsh 1-2 Upshift and Possible Diagnostic Trouble Code(DTC) P1870 (Replacement Valve Bodies)

Models that may be affected are:1996 Buick Roadmaster1996 Cadillac Fleetwood1999-2000 Cadillac Escalade1996-2000 Chevrolet Camaro, Corvette1996-2000 Pontaic Firebird1996-2000 Chevrolet and GMC C/K, M/L1996-2000 Oldsmobile Bravada with 4l60-E Automatic Transmission (RPC)

A harsh 1-2 shift or DTC P1870 is caused by wear in the control valve body. Here arethe replacement valve bodies with new isolator valve per applications. The cost of these valvebodies vary from model to model, check with your local parts supplier.

Technical Bulletin #636� Transmission: 4L60E

� Subject: Harsh 1-2 upshift & possible DTC P1870 (replacement VB)

� Application: General Motors

September 2001

GM #636 ��Page 1 of 2

#636 ��Page 2 of 2 ATRA Technical Bulletin

“Portions of materials contained herein havebeen reprinted with permission of GeneralMotors Corporation, Service Operations”