| Subject: | Tech 2 Information on 4L60-E Shift Adapts (Clearing
Shift Adapts) |
| Models: | 2002 Chevrolet Trailblazer |
| with 4L60-E Automatic Transmission (RPO M30) |
| and 4.2 L Engine (VIN S -- RPO LL8) |
The above listed vehicles have PCM software that does not
allow the Tech 2 to display or clear shift adapts. Even though the
shift adapts will not display, they will function as expected. Since the shift
adapts modify line pressure, it is required to clear them during a significant
transmission repair.
Important: If the adapts are not cleared, the customer may comment on either soft
or harsh shifts after a major repair.
To clear the shift adapts, it is necessary to disconnect power to the
Powertrain Control Module (PCM) for 35 minutes. Refer to the Powertrain
Control Module (PCM) Replacement procedure in the Service Information.
