Pre-Sales Frequently Asked Questions


COMPUSHIFT is a brand name of HGM Automotive Electronics. It is the next generation of transmission control. It is available for a wide range of different transmissions. Click here to find your transmission and be guided through to a customized kit that will be perfect for you!

How do I setup COMPUSHIFT using the App?

Setting up COMPUSHIFT using the App is a relatively simple process. Please refer to the following link to see a video here - link.  

Can I use COMPUSHIFT with a diesel engine?

Yes. HGM supplies COMPUSHIFT with settings for both gas and diesel engines.

Can I connect the tachometer output from my ignition system both the tachomter input to the COMPUSHIFT and a tachometer gauge on the dash?

Yes. This usually works just fine.

How do I get the tachometer to work on COMPUSHIFT on a diesel engine?

Newer diesel engine control system's often have a tachometer wire, just like a gas engine. Older diesel engines sometimes have a tachometer wire that comes off the alternator. Often these are not quite the right speed, so you need a corrector to fix this. Alternatively, you can use a crank speed sensor. For many applications, you don't really need a tachometer input to the COMPUSHIFT system. It will usually run correctly without one, especially if the engine isn't a high performance gasoline engine.

Do I need a laptop computer to program the system?

No. All adjustments and programming to COMPUSHIFT can be done with the downloadable free app and a mobile phone or tablet.

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

On most transmissions and control programs, 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.

How do I run a speedometer with COMPUSHIFT?

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.

How do I use an existing throttle position sensor (TPS)?

Many COMPUSHIFT customers are using a carbureted gasoline or diesel engine. For these applications, the throttle position sensor provided in the COMPUSHIFT kit is used. But, if you use COMPUSHIFT with an electronically fuel injected engine, you can often use the existing throttle position sensor instead of the provided one. Here's a little explanation on how the TPS works, and how to use the existing one:

A throttle position sensor usually has three wires: +5 volt power, ground, and signal. The power and ground wires supply a reference voltage to either side of a variable resistor. As the shaft rotates, the signal wire has a voltage that varies between +5 volts and ground.

In order to connect COMPUSHIFT to an existing TPS, you only need to connect two wires, the ground wire and the signal wire. These can be piggybacked on top of the existing wiring using an in line wiretap, but they should be done as close as possible to the sensor. The +5 volt wire coming from the COMPUSHIFT should be left disconnected, but insulated to prevent a short circuit.

How much does COMPUSHIFT cost?

Click the following link to use the COMPUSHIFT Configurator to price a kit to suit your particular build - click here

How do I mount the COMPUSHIFT display in my vehicle?

The COMPUSHIFT display has a 1/4-20 bolt in the back that can be used to mount the display in the same way that a camera mounts to a tripod. A good source of mounts in RAM Mounting Systems.