Operation CHARM: Car repair manuals for everyone.

General Information

^ Perform the road test using a Scan Tool.
^ Perform this test only when traffic and road conditions permit.
^ Observe all traffic safety regulations.

The PCM calculates upshift points based primarily on two inputs: TP ANGLE and VEHICLE SPEED. When the PCM says that a shift should occur, an electrical signal is sent to the shift solenoids. The solenoids in turn move the valves in order to perform the upshift.

The shift speed chart refers to TP ANGLE instead of Min Throttle or WOT in order to make shift speed measurement more uniform and accurate. A scan tool should be used in order to monitor TP ANGLE. Some scan tools have been programmed to record shift point information. Check the instruction manual in order to see if this test is available.