Attention: This Item Has Been Discontinued and is No Longer Available.

Increase Road Speed Governor on Big Rigs without an ECM Programmer!

Big Rig Speed Governor Calibrator Control Unit for Semi-Trucks.

Precisely Control Your SGL (Speed Governor Limit) Without Programming or Passwords.

For example, trucks with top speed governors set at 65mph can be made to run faster to compensate for loss of ground speed due to worn, but legal, truck tires. The speedometer will also be more accurate, reflecting your "actual ground speed".

To Measure Accurate Ground Speed Use GPS Or The Timed Mile Method.

Time your vehicle between interstate mile posts. Count the number of seconds between mile-sticks, divide by 3600. Example: Punch into calculator this way. 3600 divided by 57 seconds = 63.157mph. Another example: 3600 / 52.5 seconds = 68.571mph. This formula works for kilometers per hour just as well.

When you get the unit, all you have to do is plug it in to the speed sensor connectors located at the rear of the transmission on the output shaft.

Connect 12v power from a switched ignition circuit so the device is powered anytime the ignition is on, then drive, no further adjustment required. This device is fully adjustable. So, if you want to adjust your Speed Governor, top speed later, we include instructions so you can set it anywhere you like. *RCA Voltage adapter may be required depending on ECM Programming.

Top speed is ultimately limited by Maximum Governed RPM programming of the engine control module (ECM) and can not be changed by this device.

Driver always controls top speed with throttle pedal or cruise control, just like normal.

• -50% to +50% decrease/increase in ground speed.
• Fully Operational Cruise Control
• **1992 - 2012 Cummins, Caterpillar, Detroit, Mercedes-Detroit, Navistar, Volvo engines.
• Works on just about any class 8 electronically controlled truck engine regardless of brand.
• Manual 6 through 18 speed transmissions
• Most Autoshift Transmissions - Fully Automatic Transmissions supported but depends on existing ECM programming.

**PRIMARY REQUIREMENT: ALL Trucks Must Have a Speed Sensor Located on the Tailshaft (Output Shaft) of the Transmission, Any Other Location Will Not Work.
If your truck does not have a speed sensor located on the tailshaft of the tranny, the device will not be compatible with your system.

The Speed Governor Calibrator Control Unit Requires an Installation kit to enable hook up to the speed sensor(s).

ATTENTION XM6 Users: All Installation cables and Adapter Cables will fit the New XM7 Model Control Unit.

The main installation cable is a primary requirement. Many trucks require an adapter cable to be used for different speed sensor connectors. Once the correct adapter is chosen the installation will fit most brands of trucks, including 1992 through 2012 Freightliner, Kenworth, Peterbilt, Sterling, Western Star, Volvo and others with Weather-Pack, Metri-Pack or Deutsche speed sensor connectors. See all adapter cables here: SafetyPass Pro Catalog

Check Your Speed Sensor Connectors Prior to Ordering.

We have found that it is a good idea to visually inspect your speed sensor connectors that are located at the extreme rear tailshaft of the transmission on the output shaft. Click Here to check speed sensor location and connector types. Truck manufacturer's have been known to use alternate connectors or you may have two speed sensors on your truck that are not listed in the shop manuals. If you have two speed sensors or two speed sensor leads you may need a Y adapter cable. Check your speed sensor connectors prior to ordering.

How to Install the Speed Governor Calibrator

Click Images to Enlarge.

All connections to the vehicle, no matter the make of the truck, are made in one specific location Only; Directly at the rear of the transmission on the output shaft, just in front of the driveshaft U-joint, at or near the vehicle road speed sensor location.

Here is an example of a 2006 Volvo Conventional with Cummins ISX engine and 10-speed Fuller Transmission using the Metri-pack adapter cable included with every SafetyPass Pro.

Use the Metri-Pack adapter Cables along with the Main Cable to plug directly into the top of Metri-Pack Speed Sensor and ECM leads.

Once connectors are located - Just separate the existing connectors and plug-in using the installation kit.

See Installation Video

2004 Kenworth conventional with C-15 Caterpillar Engine and 18-speed Rockwell Transmission. This is the typical Speed Sensor location for most heavy trucks.

The Installation cable simply plugs into the vehicle's existing speed sensor connectors located at the rear of the transmission on the output shaft.

Locate the speed sensor(s) then follow computer leads to locate the in-line connectors, usually 6" to 12" upline from the sensor location.

Use the Main Cable to plug into ECM and speed sensor leads using Weather-Pack Connectors.

Simply separate, disconnect, or un-plug existing vehicle speed sensor connectors and plug-in the installation cables to the speed sensor(s) connectors.

The cables can only be mated one way so it's easy to get up to speed fast. The installation cables can be permanently installed in under 30 minutes. Temporary installation (or removal) takes about 5 minutes.

The Main Cable plugs into speed sensor leads and ECM leads using sealed Weather-Pack Connectors The Main Cable is required for proper installation.

Available Adapter Cables For Use with Main Cable

Metri-Pack adapters for newer trucks, allows for easy plug-n-play hook up to most newer class 6-8 trucks.

Included with every SafetyPass Pro.

Click images to Enlarge

NEW! Metri-pack 280 connectors Fits Newer Mack Trucks. Also used as alternate connectors on some Kenworth trucks. These connectors simply plug in to the Speed Sensor Leads and the ECM leads, similar to Weather-Pack connectors and in the same location. Sold Separately

Deutsch adapter cables for older (pre-2001) International Navistar Trucks. Sold separately.

Trucks with two sensors or two leads (4-wires) require a Y adapter cable. Sold separately.

See ALL Cable Adapters in the Catalog.

Interior Connections

Route RCA connectors from Installation Cable to cab interior and interface plug into Mating RCA connectors on Control Unit. Plugin the power to standard cigarette lighter receptacle. Power up the speed module and you are ready to go.

The Control Unit can be placed behind the Dashboard or anywhere within the vehicle interior.

Commercial grade electronic components and state-of-the-art construction techniques are employed to insure long product life and reliable, consistent results under harsh conditions of over-the-road trucking. Thermal protection for integrated circuits creates a smooth and stable environment for years of trouble free service and customer satisfaction.

Worn (Bald) Truck Tires Slow Down Your Truck's Maximum Ground Speed.

Semi truck tires have approx. one inch tread depth when new. When they get worn down, the diameter of the tire decreases. This can result in a 4% decrease in truck speed.

If a speed governor limit (SGL) is set at 65mph, a truck with bald tires will have a top ground speed of only 62.4mph. This also causes speedometer error as the speedometer is still reading 65mph.

Also, more miles are recorded on the odometer and ECM than are actually being driven. Thus, shortening the truck manufacturers warranty by 2% to 4%. A 500,000 mile truck warranty may run out at only 480,000 actual ground miles.

The driver will also endure an increased risk of accidents and road rage from motorists who just want to do the speed limit but are frustrated by the rolling roadblock ahead as 2 trucks try to pass each other.