C 3500 Truck 2WD V8-6.6L DSL Turbo VIN 1 (2002)
PROM - Programmable Read Only Memory: All Technical Service Bulletins
A/T - Harsh/Delayed 2nd to 1st Gear Downshift/DTC's Set
File In Section: 07 - Transmission/Transaxle
Bulletin No.: 02-07-30-020
Date: May, 2002
TECHNICAL
Subject:
Harsh or Delayed 2-1 Downshift, Neutral Feel at a Stop, Shift Busyness, DTCs P0708, P0847, P0872, P0875, P1711, P1713 (Reprogram TCM and, if
necessary, Reprogram PCM)
Models:
2001-02 Chevrolet and GMC C/K 2500/3500 (3/4 and 1 Ton) Series Pickup Models (Silverado and Sierra)
with Allison(R) Series 1000 Automatic Transmission (RPO M74)
Condition
Some customers may comment on a harsh or delayed 2-1 downshift, a neutral feel at a stop or shift busyness (excessive shifting). Upon investigation, the
technician may also find one or more of the following DTCs set:
^
P0708
^
P0847
^
P0872
^
P0875
^
P1711
^
P1713
Correction
Reprogram the Transmission Control Module (TCM) with the new service calibrations which were available from Techline starting March 24, 2002 on
the TIS2000 version 3.5 or later. These calibrations are electronic calibrations and are NOT available from GMSPO.
These new calibrations will address the conditions shown.
Important:
2002 Vehicles with 8.1 L Engine - If the concern is shift busyness, the PCM must also be reflashed to gain maximum benefit from the new TCM
service calibration. This calibration was available from Techline starting March 10, 2002 on the TIS2000 version 3.0 or later. If the concern is not
shift busyness, this step is not required.
This additional step is not required on vehicles with a 6.6L diesel engine (RPO LB7) or 2001 vehicles with an 8.1L engine (RPO L18).
Warranty Information
