With the installation complete it was time to do what we feared most, the electronic wizardry that’s normally the domain of 12-year-olds—programming. Fortunately for most of us, a PC, laptop, or other type of computer isn’t needed as the system is delivered with factory set programming; however a PC can be connected via the USB port for system software updates and tuning if desired. Dual CAN buses can connect to existing engine management or body control computers. A MAP sensor can be connected for turbocharged applications if needed.

For the system to operate, the TPS has to be calibrated. Start the engine and allow it to warm up enough so it’s no longer on fast idle or choke. Then turn the engine off.

With the vehicle in park and engine off, turn on the ignition switch to provide power to your Compushift II. Wait five seconds.

Enter setup mode on the display and press the right arrow (next screen), the TPS Calibration Setup screen is visible.

Press the enter button and you’ll have five seconds to completely depress and release the throttle pedal. This one stroke of the throttle pedal should be done in a slow, even motion before the five seconds elapse.

Once you’ve stroked the throttle, wait five more seconds, and then observe the status LED on the Compushift II Controller—it should be green and solidly lit (not blinking).

Depress the throttle pedal completely and hold it for five seconds. The LED should still be green and solidly lit.

With the TPS calibrated, all that was left was to take the truck for a drive. Under light throttle the Gearstar E4OD shifted quickly and smoothly, but when we stuck our foot in it, the shifts were later and much firmer. We found the gear ratios are ideally suited to our needs but the biggest difference was the overdrive top gear and the lockup converter; at highway speeds the reduced rpm has made a noticeable reduction of engine noise in the cab and throttle response without the slippage of a standard converter is noticeably improved. Although we haven’t had the opportunity to compare mileage, we’re hopeful and will report soon. Stick around, there’s more Hot Rod Hauler to come. CCT


Q. Do I have to purchase the display/programmer in order to correctly install Compushift?

A. No. Your dealer/reseller can send you a controller pre-programmed with most of the needed settings. Throttle calibration and shift point/shift pressure adjustment can be done without the display. The display does offer the greatest flexibility in setup, though. It can also serve as a “digital dashboard”, providing you with running information about vehicle and transmission performance.

Q. Do I need a laptop computer to program the system?

A. No. All adjustments and programming to Compushift can be done with the handheld display/programmer.

Q. Does the torque converter clutch (TCC) unlock during gear changes?

A. The torque converter clutch always unlocks during downshifts, and sometimes during upshifts, depending on the vehicle speed and throttle position. It is safe to upshift under light load while the TCC is locked, and most OEM systems do so.

Q. How do I run a speedometer with Compushift?

A. Compushift provides an output signal for driving speedometers. This signal is called reproduced TOSS. This signal replicates the signal coming from the TOSS (transmission output shaft speed) sensor.

This signal should be used when you have an existing OEM speedometer or engine control computer that uses the TOSS sensor. Reproduced TOSS comes off of the 25-pin connector and comes with enough cable to connect back to an original TOSS plug.

A device called the Cable-X can drive mechanical speedometers if necessary. Built by Abbott Enterprises, the small Cable-X box motor rotates a speedometer cable at a rate proportional to an electronic speed input, and is calibrated to match your speedometer using internal switches. HGM is an authorized Cable-X reseller.