Savana 1/2 Ton Van V8-5.7L VIN R (2001)
Speedometer Module: Customer Interest
PCM - Recalibration for Jerking Motion Symptom
File In Section: 06 - Engine/Propulsion System
Bulletin No.: 01-06-04-041
Date: August, 2001
TECHNICAL
Subject:
Vehicle Jerking Motion at Speed of 113 km/h or 70 mph
(Reprogram PCM For Correct Speedometer Calibration)
Models:
2001 Chevrolet and GMC G-Van Models
with 5.7 L Engine (VIN R - RPO L31) and SEO 9B9 (Electronic Speed Sensor)
Important:
"IPC" dealers are not authorized to utilize this service bulletin.
Condition
Some customers may comment on a jerking sensation when the vehicle reaches 113 km/h (70 mph).
Cause
Special Equipment Option (SEQ) 9B9, available only to fleets, was intended to limit the vehicle speed at 113 km/h (70 mph) through a mechanical road
speed governor. However, for 2001 models, the speedometer calibration incorrectly shuts the fuel off at 113 km/h (70 mph) prior to the mechanical
governor engaging This abrupt fuel shut-off/on may cause the vehicle to jerk.
Correction
The powertrain control module (PCM) must be reprogrammed with a calibration that does not include the 113 km/h (70 mph) limit. The new calibration
will instead allow the road speed governor to smoothly limit the speed to 113 km/h (70 mph).
