UltraGauge MX Frequently Asked Questions

I want transmission temperature, which model should I buy?

The connector and interface that are used to communicate with the vehicle is known as OBDII.  Various standardized emission parameters can be accessed using the OBDII.  Transmission temperature is not a standardized OBDII parameter. However, it may be available as a proprietary manufacturer parameter. (Please see additional FAQs below), Only the UltraGauge MX has the potential to access manufacturer parameters. The UltraGauge EM Plus can only access standardized OBDII parameters and cannot access manufacturer parameters.

Oil Pressure?

The OBDII standard defines many emission related parameters, oil pressure is not one of them.   However, Oil pressure may be available if your vehicle actually has a oil pressure sensor and if the manufacturer has created a proprietary code and has made access possible via the OBDII. Please continue reading this FAQ page to learn more.

How is the UltraGauge MX different from the EM plus?

The EM Plus and the MX are identical, except that each provide the following additional features:


Ultragauge MX: Ability to access additional standardized gauges, if the vehicle supports them, and manufacturer parameters, if manufacturer codes are known.

Ultragauge Plus: Readiness Monitors & Performance Functions


The additional features in the EM Plus are not available on the MX, and the MX feature is not available on the EM Plus.

What are Manufacturer Codes?

Manufacturer codes are a means to access hidden parameters (gauges) that the manufacturer has inserted into the Standardized OBDII for their own purposes. For example, Transmission temperature is not an OBDII parameter and, if available at all, is only accessible using the Manufacturer's code.  Many Manufacturer parameters are a duplicate of standardized OBDII parameters, while others are wholly separate and not included in the standardized OBDII parameters.  Standardized OBDII parameters are focused on emissions, while Manufacturer parameters are not focused on emissions and can be any useful parameter the manufacturer has seen fit to insert.  Codes are manufacturer proprietary, and vary by manufacturer, year, model, and engine size.


Codes are created by the manufacturer of the vehicle, not by UltraGauge



Here is an example of a code for a 2015 Toyota Landcruiser as it would be viewed on the UltraGauge MX programming screen:


Transmission Temp #1 (*C)
Abbr1: TFT    Abbr2: 1*C
TDATA: 07E121D9000000
TCTRL: 92     RCTRL: 10
RPOS: 0810    MTCH: 210000
X: 0001 /: 0100 +: FFD8
Out Format: 00    Ave: 00
Left/Right: 32


(Same as above with comments)
Transmission Temp #1 (*C)
Abbr1: TFT    Abbr2: *C (This sets the text abbreviation that is displayed with the gauge value)
TDATA: 07E121D9000000 (This is the manufacturer code to access the parameter)
TCTRL: 92     RCTRL: 10 (This tells UltraGauge how to send the code and where in the response the gauge value can be found)
RPOS: 0810    MTCH: 210000 ( This tells UltraGauge how many bytes the data is and where it is in the vehicle's response)
X: 0001 /: 0100 +: FFD8 (This is the math applied to the response to render the gauge)
Out Format: 00    Ave: 00 (Special Formatting such as Temperature, or pressure, etc.)
Left/Right: 32 (number of digits to display too the left and right of the decimal point)


What is the difference between Manufacturer and Standard Gauges?

The OBDII standard describes certain parameters (gauges) which can be accessed via the OBDII. The "OBDII" is a collection of mechanical, electrical and protocol standards which essentially allow a device to attach to the vehicle and access vehicle emission parameters.  Many of the parameters are left to the manufacturer’s discretion to support or not.  This is why the gauges available through UltraGauge are vehicle dependent.

All Manufacturers have the ability to access additional vehicle parameters beyond those specified in the OBDII standard.


For example, there is no OBDII parameter for Transmission temperature; however, many manufacturers can
access this parameter.  Likewise, there is a standardized parameter for Fuel Level %, but manufacturers commonly did not support it via the OBDII
on earlier vehicles, yet many manufacturers can access it.

I don't see my vehicle on the pre-programming option list on the UltraGauge MX product page?

The pre-programming options shown are the sum total of all the programming options we currently provide.  The options were created with the assistance of UltraGauge enthusiasts who were able to confirm a set of codes and that the resulting gauges were correct for their vehicle.  The limited number of pre-programming options does not imply that there are not codes for a vehicle not listed.  All vehicles have hidden manufacturer parameters.  However, the codes to access these parameters may not be public for all vehicles.  Often only a handful of codes are known for a specific vehicle.  Codes are created and controlled by the vehicle manufacturer.


If your vehicle is not on the pre-programming list but you know that codes are available, then select a pre-programming option with the same protocol as your vehicle.  If your vehicle uses 11-bit CAN choose the Tacoma option.  If your vehicle uses 29-bit CAN (Honda and Volvo), choose the Honda option.  If your vehicle is made by a non-USA company, and it is older than 2008, your vehicle will likely use the 9141 or KWP2000 protocol.  Please see the 9141/KWP2000 FAQ below.


If you are unsure as to which protocol your vehicle uses, please see the "Which protocol does my vehicle use?" FAQ below.

Are Manufacturer Codes available for my vehicle?

The UltraGauge MX is offered with several pre-programming options.  These pre-programming options are the most common "codes" for the particular option.  However, these codes may or may not work for your particular vehicle. See "Why Doesn't the MX have codes for my vehicle?" below.

All vehicles have hidden manufacturer parameters.  However, the codes to access these parameters may not be public for all vehicles.  Often only a handful of codes are known for a specific vehicle.  It takes automotive enthusiast to reverse engineer and make codes available .  The best source for codes is an automotive forum specific to your vehicle.  Please note that most vehicles which use the 9141 or KWP2000 protocols do not make manufacturer codes available via the OBDII, and the MX can not access manufacturer parameters in those vehicles.


List of Manufacturer gauges supported by each pre-programming option for the UltraGauge MX

Why doesn't the MX have Manufacturer codes for my vehicle?

The MX is a tool that in addition to general Ultragauge functions, can also access hidden manufacturer parameters.  There have been some 50,000 different combinations of year, make, model & engine size since the introduction of OBDII in 1996.  For each of these there can be hundreds of unique codes.  As a result it is impractical for UltraGauge to provide and maintain a list of codes, especially since there is no means to verify a code without testing it against a specific target vehicle.  The best source for codes, if any exist for your vehicle, is an automotive forum specific to your vehicle. It is important to emphasis that codes are not UltraGauge codes, but codes created by the vehicle's manufacturer.

Will Manufacturer codes soon be added for my vehicle?

Codes are only added after interaction with motivated UltraGauge users.  Codes can only be verified by a user with the specific target vehicle.  As such, no additional codes can be added without a user that has gone through the effort to seek out codes and interact with support to verify the codes are valid.

Will the pre-programming codes work for my matching vehicle?

The pre-programming codes are considered generic codes.  That is they generally work for most vehicles of that type.  They have also been chosen as they do work on the broadest set of the indicated vehicle type.  However, manufacturers can and do change codes from year to year, model to model, make to make and engine size to engine size.  As a result, there is no guarantee that the code(s) will work for your specific vehicle.  The best means to confirm that codes will work for your vehicle, is to search a forum specific to your exact vehicle and find codes that other users have confirmed work for their same vehicle.  In general most customers find that most or many of the pre-programming codes do work on their vehicles.  However, there can be a great many more gauges (and codes) available for a particular vehicle and forums are the best place to find them.   If you can find the code, then the MX can access the gauge.


List of Manufacturer gauges supported by each pre-programming option for the UltraGauge MX

I found a code for my vehicle that is used on a competitors product, will the code work on Ultragauge?

It depends. If the code is actually the manufacturer's code, then it will work with minor formatting changes. If the code has been obfuscated, so that the actual manufacturer code is concealed, then it is not a valid code and will not work on UltraGauge and effort will be needed to convert the code to its true form.  If this is the case, please create a support ticket and we will work with you to determine the true manufacturer code.
Please see the MX programming supplement on the Ultragauge online user manual page for a conversion example.

Which additional standard gauges are available?

Please see the list of standardized gauges that can be added to he MX, if supported by the vehicle

My vehicle uses the 9141 or KWP2000 protocol, can I still use the MX?

Yes, all the functions in the MX, except for the ability to access manufacturer gauges, will work on vehicles with 9141 and KWP2000 protocols.  Manufactures which use 9141 and KWP2000 protocols typically have an alternate proprietary interface to access manufacturer parameters.  As a result the MX can not typically access manufacturer parameters for vehicles that use the 9141 or KWP2000 protocols.  There are some exceptions to this, but they are very rare. However, the MX can be programmed to access additional standardized parameters. For example, if your vehicle supports "Turbo Charger RPM", this could be accessed via the MX, but is inherent to the MX's gauge set. The 9141 and KWP2000 protocols are older protocols and are found in older vehicles. Such vehicles typically do not have many parameters and it would be rare to find a parameter available in the vehicle which is not included in the MX's gauge set.

Excepting this one feature, all other features of the MX will work in a 9141/KWP2000 vehicle. Unless you plan to use the MX in multiple vehicles, its best to select the Ultragauge EM Plus for the 9141/KWP2000 vehicles.

The 9141 Protocol is typically found on pre-2008 non-USA and Chrysler Vehicles. The KWP2000 protocol was an enhanced version of the 9141 protocol that came out in the early 2000's and was replaced in 2008 by the CAN protocol.   KWP2000 is rare and found on certain Audi's, VW's, BMW's, etc. Most Manufacturers went from 9141 directly to CAN and skipped KWP2000.

Can a pre-programmed MX be used on other vehicles?

The MX will work on any OBDII compliant vehicle, regardless of pre-programming.  The MX specific function, that is the ability to access manufacturer parameters, will also work on any OBDII compatible vehicle for which manufacturer codes are available.  Codes for one manufacturer WILL NOT work for a vehicle of another Manufacturer.  Its common that codes for one vehicle model will not work for a different model of the same manufacturer, even if they are the same year.  More specifically, codes are year, make, model and engine size specific.  A pre-programmed MX can be easily manually reprogrammed for a different manufacturer or different year or model of the same manufacturer, if the codes are known.  See "What is meant by "pre-programming..." below.

What is meant by "pre-programming" and "reprogramming"?

The terms "programming codes", or "reprogramming codes", tend to concern some people.  Its not the best description of the task.  It may be more appropriate to use the term "configure codes" or "reconfigure codes".  Programming codes involves entering in less than 15 2-digit numbers.  The Ultragauge MX has a dedicated "programming" menu for each of the 8 possible Manufacturer gauges (Mgauges).  There are several fields each clearly labeled.  The numbers for each field are simply entered. Once complete, UltraGauge will access the Gauge.  The process of entering the codes is trivial.   The process of finding the codes is the challenge, depending on the vehicle.

Can I help create a new pre-programming option?

If you have put in the energy into finding, confirming, and tuning a set of Manufacturer gauges for a specific vehicle, and you would like to make the codes available to other owners of the same vehicle, Ultragauge will create a new pre-programming option.  Please create a support ticket and attach a screen shot of the 8 Mgauges.

Which protocol does my vehicle use?

For vehicles in the USA, all 2008 and newer are required to use the CAN protocol.  If 2007 or older, then your vehicle can support any of the protocols.  Foreign vehicles 2007 and older typically use 9141 or KWP2000.  See the 9141/KWP FAQ above.

The Vehicle Gauge Availability Estimator reports the protocol of all vehicles in our database.

For additional information, please see our compatibility page.

If you did not find the answer you seek please see the following common support questions/issues