COMPUSHIFT Mini Manual – COMPUSHIFT Mini Manual
Installing the COMPUSHIFT Mini
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2.5.2 Pressure Sensor Check
With the vehicle in park, start the engine. Press the "up" key once to select the pressure screen.
PRESSURE
Press the "select" key. The display should show something like:
90 PSI
Verify that the screen shows some pressure and that this pressure changes with throttle.
Turn off the engine.
2.5.3 Speed Sensor Check
With the vehicle in park, start the engine. The display should show this screen:
SPEED
Press the "select" key once. The display should now show:
0 MPH
Have an assistant sit in the passenger seat and hold the COMPUSHIFT Mini.
Drive slowly and verify that the on screen speed display matches the vehicle speedometer.
If all of these tests pass, then you are ready to
calibrate the throttle position sensor
2.6 Throttle Position Sensor Calibration (GM)
2.6.1 Introduction
The throttle valve cable, or TV cable, connects between the throttle assembly on the engine and the transmission.
The TV cable communicates the position of the throttle to the transmission hydraulics and governor assembly. This
is used to scale shift points and control shift firmness. Because the TV cable directly affects the line pressure in the
transmission, measuring the line pressure tells you what the throttle position is. This is how the COMPUSHIFT Mini
uses a pressure sensor to determine the throttle position.
The pressure variation in each transmission is different depending on the make, model, and customization of the
transmission. The throttle position sensor calibration process measures the lowest and highest line pressures as the
TV cable is moved, and internally associates those pressures with the 0% and 100% throttle positions. Once set,
those positions are used to calculate the actual throttle percentage.
2.6.2 Calibration Procedure
Put SAFETY FIRST. You should not attempt the throttle sensor calibration unless you are thoroughly
familiar working around engines.