Multifunction Decoder Reset
Summary: Sometimes your Multifunction Decoders will lose their settings, or mistakes were made when configuring a new decoder. Rather than return the decoder to the dealer or manufacturer, thinking it is defective, a simple reset will restore your decoder to its factory defaults.
Multifunction Decoder Reset
A decoder reset forces all the CV values back to the initial factory settings. This is useful if your decoder becomes unusable or if you want to have a fresh start with the decoder. Not all decoders have CV reset functions, please refer to your owner's manual for full instructions and details on it's use. Some decoders allow you to reset everything, or only certain sections of the decoder, such as the speed table or everything except the speed table.
The reset is entirely handled by the decoder. This function is non-intrusive, that is, you don't have to use this feature at all. The only necessary tools to activate this function is a method in which you can program various CVs. This can be handled by the throttle of most systems, or through the use of DCC software.
- The reset procedure is not part of the NMRA's Digital Command Control Standards or Recommended Practices (RPs), so there is no default method to reset a decoder. Also, see below for a note on the Default Address.
The following table has general notes on resetting a decoder. Read the specific text below for any additional information which may apply.
If you don't know the address, use a programming track to accomplish a reset.
Example: A DCC system's command station which utilises a single two wire track output can switch between normal and Service Modes as required. When in Service Mode changes will be applied to every locomotive on the track which is connected to that output. Other command stations may have a dedicated and labelled programming track output for this specific purpose.
Always check the manufacturer's instructions. Not all manufacturers use the same CV for the same purpose. Some decoders must be reset using Operations Mode, others will be using the programming track. A jumper inside the locomotive may need to be installed or removed, or the position of a switch changed.
As mentioned above, there is no set procedure to accomplish a decoder reset.
- A Manufacturer ID equalling 255 or multiple readings of 255 when reading other CVs is an error message.
- Cannot Read CV is also an error message.
- The system did not get a response back from the decoder. Check connections and clean track if necessary. Try another locomotive for comparison.
- When trying to read CVs of a SOUND decoder a programming track booster. Do not use a DCC Specialties "PowerPax"!
- Do not connect any type of programming booster to an NCE Power Cab.
- The Manufacturer ID (CV8) is for the locomotive's decoder, not the system you are programming with. The manufacturer id is held by CV8.
- It is always a good idea reboot / power cycle your system and the decoder after a factory reset. Some decoders might not be completely reset until the power is removed and restored. Similar to rebooting a PC after it is updated.
- To learn more about configuration variables see the related DCCWiki Page: Configuration Variables.
Typical Reset Values
Don't forget to cycle the track power OFF and then ON to complete the reset. This can be as easy as tilting the locomotive to raise the wheels on one side off the rail and waiting a few seconds. You may need to power cycle your DCC system too.
|Manufacturer||ID No. in CV8||CV to Write plus Value|
|Lenz Elektronic||99||CV8 = 33|
|NCE Corporation||11||CV30 = 2|
|Digitrax||129||CV8 = 8|
|ESU (LokSound)1||151||CV8 = 8|
|Train Control Systems (TCS)||153||CV8 = 8 or CV30 = 2|
|SoundTraxx: DSDLC, DSX, Tsunami3||141||CV30 = 2 CV8 = 8|
|QS Industries||113||See text below|
|Model Rectifier Corp (MRC)||143||CV125 = 1|
|Broadway Limited Imports (BLI)||38||CV8 = 8|
|Bachmann Trains 2||101||CV8 = 8|
|MTH||27||CV8 = 8|
|DCC Concepts||36||CV8 = 2 or 8|
|Kato Precision Industries||40||CV8 = 8|
|Hornby Hobbies Ltd||48||CV8 = 1|
|Gaugemaster||65||CV8 = 8|
|Atlas Model Railroad Products||127||CV8 = 99|
|ZTC||132||CV8 = 8|
|Zimo Elektronic||145||CV8 = 8|
|LGB||159||CV55 = 55|
|Arnold / Rivarossi||173||CV8 = 8|
CV8 is the Manufacturer ID. This value is assigned by the NMRA. Writing any value to CV8 does not change its contents as it is a read-only variable.
1 ESU recommends using the programming track.
2 Bachman products may be equipped with Soundtraxx decoders
3 Programming track with booster required.
- Soundtraxx (Tsunami) and QSI decoders will require a Program Track Booster or a PowerPax
- Newer Soundtraxx Tsunamis may not require the program track booster
- MRC Decoders are not reliable for read back.
- Some Lenz decoders may work with a value of 8 or 33 in CV8. Older decoders used 33.
Resetting a Multifunction Decoder
- Start by determining the decoder manufacturer.
- On the programming track read CV 8.
- Compare the number with the above chart for the ID
- If you have a LENZ decoder CV8 will equal 99
- Write to the matching CV the value shown in the table. Writing to CV8 will not change the value contained in CV8 when you read it back. When resetting the decoder, it may respond by flashing the lights or sounding the horn. Resetting a decoder will change the address back to the default. Cycle track power on and off to complete the reset. Read the instructions for the decoder to verify what should happen after a reset (headlights flashing, etc.) to determine if the process was successful.
Important: The NMRA Standards specify that the default Primary Address (CV1) for a retail multifunction decoder is 3. A factory installed multifunction decoder is exempted from this requirement by the Standard, verify with the instructions for the locomotive as to the default address. 
Manufacturer Specific Reset Procedures
Due to the increasing complexity of multifunction decoders, a complete reset may not be possible within the time limits specified by the DCC Standard. Some decoders offer the ability to reset portions of their configurations.
Decoder reset lets you reset all CV values to the initial factory settings. To reset all CV values, program CV08 to a value of 008/x08. You also have the option of resetting all values except the 28 speed step tables. To do this, program CV08 to a value of 009/x09.
Source: Digitrax website
Normally this will work with all Digitrax decoders except those noted below.
Specific Digitrax decoder notes
Add notes/comments for different proceedures for Digitrax decoders which the above doesn't apply.
- None at this time
- JMRI has a Reset menu available for previous roster entries for LokSound equipped locomotives.
- The LokProgrammer also has a Reset facility.
LokSound V5 DCC
Write the value 08 to CV8.
4.3 Resetting to factory pre-set values: You may reset the decoder settings to the factory pre-set values at any time. Write value 08 in CV 08. A reset of the sound files is only possible with the aid of the LokProgrammer 53452.
Source: Page 15 of LokSound v3.5 manual.
You can easily reset the decoder by writing the value 08 in CV 08 at any time.
Source: Page 6 of LokPilot Manual.
The LokProgrammer can quickly and thoroughly reset an ESU decoder. Use the Reset Decoder function and follow the prompts. (LokSound V5 manual, p92)
Current versions of JMRI deliberately deactivate the Reset to Default button for ESU multifunction decoders.
Prior to attempting to reset an ESU decoder, use the New Loco > Read Type from Decoder to identify an ESU decoder. Modern ESU multifunction decoders have unique identification parameters. Blindly attempting to reset the decoder model will only create new problems. Create a new roster entry, and do the reset from the menu there.
See Programming ESU Decoders for a more complete explanation of JMRI and ESU decoder interactions.
CV8 Register-8 Manufacturers Identification: Contains the manufacturer ID of the decoder, (Lenz =99). Writing a value of 33 using Register mode resets all CVs to their factory condition.
Source: Page 7 of LE1835 manual.
Other models are similar, refer to owner's manual.
Tilt locomotive to one side to disconnect from track power, wait 7 seconds to reset decoder.
CV30: Set this CV to 2 on the programming track and the decoder will reset to factory settings.
Source: Page 8 of D13SRJ ver 3.5 decoder manual.
Other models are similar, refer to owner's manual.
Addressing a Reset Decoder with the Power Cab
Recovery Mode for NCE Decoders
NCE has a feature in their DCC system software which allows for a recovery mode. This only works with an NCE DCC system and NCE decoders only.
- Program track mode / Recovery mode is not available in the SB3, SB3a and SB5.
NCE does not recommend using Recovery Mode with other manufacturer's decoders, as you may get unintended results. Not every decoder uses the same CVs for the same purposes.
Physical Register Mode
- Main article: Decoder Reset/Physical Register Mode
This mode allows you to program a decoder no matter what state it is in. You do not even need to know the address (hence the danger of programming all your decoders at once). It will also work if the decoder's memory has become corrupted.
Note the statement warning of the possibility of programming all your decoders at once.
Since there are a number of options, and the process varies depending on the command station, please read the Recovery Mode For "Dead" NCE Decoders webpage on the NCE website.
Once the process is complete, the entire DCC system must be rebooted, with the target locomotive still on the track. If successful, it should respond to address 3.
QSI decoders have a different reset procedure. Check the manual that came with the locomotive.
Some use a magnetic “wand” for the reset. If there is no “wand” then open the locomotive or an access hatch to find a reset jumper. Remove the jumper and restore the track power. There will be an audible acknowledgment at the end of the reset process. The whistle/horn is often sounded three times.
Replace the jumper and test out using address 3.
If a “wand” is used, locate the internal reed switch and place the “wand” over it for a moment. When track power is restored, the decoder will go through its reset procedure and let you know when done. The reed switch may fail at some point, causing the decoder to be stuck in reset mode. The reed switch can be removed without incurring any new issues.
To locate the internal reset (reed) switch, place the engine on active track. Slowly move the “wand” over the top of the body or tender until the decoder alerts you audibly.
QSI also has a user software reset using the following multi step procedure:
- Place engine on main track if it is still responding to its address. If not responding you may need to use the program track.
- Set CV49 to 128
- Set CV50 to 255
- Set CV56 to 113
As the decoder in the engine resets, you will hear an audible response, the horn may sound three times, or it may talk to you. Test the locomotive using address 3.
You can then go ahead and set the loco number as you desire and/or reprogram other CV’s.
- An irritating issue with QSI decoders is when they do get corrupted by a short, the locomotive can exhibit very erratic operation. Resetting it back to default will put you back in control of its performance.
If the address is known:
- Using Ops Mode, enter CV62 = x, where x is the number of the CV whose contents you want to read
- The decoder will verbally respond with the content of CV x
DSD-150 / DSX
To reset all the CV values to the defaults can be... done by programming CV 30 with 02 in service mode and turning power to the DSD off and back on. Note: This bit can be programmed only in service mode. Writing any data value during operations mode will clear all error bits to 0.
Source: Page 23 of Digital Sound Decoder Technical Reference part 2.
Resetting all the CV values to the defaults can be... done by programming CV 30 with 02 in service or operations mode and turning power to the DSD off and back on."
Source: Page 24, 25 of LC SERIES DIGITAL SOUND DECODER TECHNICAL REFERENCE.
Resetting the CVs... can be quickly reset to their factory default values using the following procedure:
- Program CV 30 to 2 (or CV 8 to 8) using either Service Mode or Operations Mode
- Place locomotive on a powered section of track. If locomotive is already on the mainline, cycle power to the decoder by turning power to the track off and then back on.
- After power is restored to the track there should be no indication of activity other than the power LED turning on for a period of six seconds. If sound comes on immediately upon restoring power, the decoder did not reset. Repeat steps 1 and 2.
- Once the six-second period has elapsed, the sound should come on and the headlight, backup light and onboard diagnostic light will blink 16 times indicating that the CVs were successfully reset.
- Tsunami should now respond to short address 3 just as it did when it was first unpacked.
- If you cannot get the decoder to reset, check to see that it has not been inadvertently locked (see “If You Forget the Lock Code” in the previous section).
Source: Page 12 of Tsunami Steam Sound User’s Guide.
To reset an Econami Decoder, there are options.
Writing the following values to CV8 will do a reset (a value of 8 is needed) or only reset groups of CVs.
- 8 = Full CV reset
- 9 = Reset CVs 1-128
- 10 = Reset CVs 129-256
- 11 = Reset CVs 1.257-1.512
- 12 = Reset CVs 2.257-2.512
Source: Econami Manual
Train Control Systems
Factory Reset Sets all CVs with a shaded value back to that value. As soon as you enter a 2 in either CV 8 or CV 30, The reset is complete.
Source: Page 1 of Advanced X series Features.
Note: Some earlier non-X series decoders also supported reset as specified above.
Decoder Reset Packet for All Decoders
A special packet, called the Decoder Reset Packet, which consists of three bytes, each having a value of zero (0). When the decoder receives such a packet, it will immediately erase all volatile memory, including speed and direction data, and return the decoder to its normal power up state. If the locomotive is at a non-zero speed, it shall come to an immediate stop.
The command station is prohibited from sending packets with addresses from 100 to 127 for a period of 20mS following the reset packet, unless the intention is to enter service mode.
This process does not alter any stored CV values, it is used to prepare the decoder for programming.
Some material, such as the cheat sheet and other details, taken from DCC Decoder Default Resets by Ted Freeman, Queensland Division, AR, and Resetting DCC Decoders, by Ron Gager of the British Region NMRA.
No Warranties Express or Implied. The decoder reset process is not part of the NMRA DCC Standard. While every effort has been made to present accurate information, reset processes described may be changed at any time by the decoder's manufacturer. A reset may also cause loss of data or sound files.
While it may be possible to overwrite default settings in the decoder firmware, unless done properly any custom variables will be lost. This usually requires proprietary hardware and software. Your dealer may be able to provide this service.
Software such as DecoderPro is useful to restore decoder parameters after a reset, but the contents of the decoder must have been read and stored on your computer prior to any event requiring a reset.
- The default value for this Configuration Variable is 3, if the decoder is not installed in a locomotive or other unit when shipped from the manufacturer.