Harsh or Delayed 2-1 Downshift, Neutral Feel at a Stop, Shift Busyness, DTCs P0708, P0847, P0872, P0875, P1711, P1713 (Reprogram TCM)
| 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® 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 following conditions:
2001 | 2002 |
|---|---|
Delayed 2-1 downshift at a stop | 2-1 downshift quality concerns |
Flare & bump on low speed coast-down and throttle reapply | Cold shift quality concerns |
2-1 closed throttle neutral feel | *Shift busyness |
Harsh 2-1 downshift | DTC P0708, P0847, P0872, P0875, P1711, P1713 |
Shift busyness | 2-1 closed throttle neutral feel |
*Important: 2002 Vehicles with 8.1L 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
For vehicles repaired under warranty, use:
Labor Operation | Description | Labor Time |
|---|---|---|
K5364 | Module, Transmission Control - Reprogram | 0.4 hr |
J6355 | Powertrain Controller -- Reprogram | 0.4 hr |
