Dakota Digital GPS-50-2 User Manual

mounting requirements on

the bottom of

page 6

.

GPS-50-2

GPS Speed and Bus Interface Module

IMPORTANT NOTE! When used to operate a cruise control, see the special

Connection for GPS
speed signal to other
electric speedometers.

GPS-50-2

GPS INTERFACE

OPTIONAL
ANTENNA

setup/status switchsetup/status switch

Connection to Dakota
Digital gauge system.

GPS-50-2

GPS INTERFACE

OPTIONAL
ANTENNA

Mount the outside
air temperature
sensor in the front
grill area or another
location that can get
good air flow while
the vehicle is being
driven.

www.dakotadigital.com

605-332-6513

ACC PWR

TEMP +

TEMP -

GROUND

SPEED 1

BATTERY

BIM I/O

SPEED 2

CRUISE

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605-332-6513

ACC PWR

TEMP +

TEMP -

GROUND

SPEED 1

BATTERY

BIM I/O

SPEED 2

CRUISE

BIM-xx-2
Power

Connect to main
chassis ground

+12V

CONSTANT BATTERY POWER

(fused 5 - 20 AMP max)

+12V

(fused 5 - 20 AMP max)

Standard speedometer output.

Connect to
BIM-xx-2
power/data
harness
if needed

Connect to
GPS-50-2

KEY ON POWER

AC speedometer output.

Cruise control speed output.

BIM-xx-1 adapter harness

BIM-xx-2 6 foot power/data harness

+12V

CONSTANT BATTERY POWER

(fused 5 - 20 AMP max)

Accessory power and
ground provided by BIM
power/data harness.

RED WIRE

BLACK WIRE

optional speed and
cruise control outputs.

BLACK WIRE

RED WIRE

optional SEN-15

+12V

KEY ON POWER

(fused 5 - 20 AMP max)

Connect to main
chassis ground

To gauge control box
or BIM-xx-1

Connect directly to another BIM-xx-2
or to the BIM-xx-1 adapter harness

& data
connectors

This Bus Interface Module can be used to provide an accurate speedometer signal with most manufacturers’ gauges and
also with a Dakota Digital system to provide speed, compass with air temp, clock, and altimeter functions. There are two
speedometer outputs to work with standard speedometers and a dedicated cruise control output. There are two interface
(I/O) ports on the module for use with a Dakota Digital gauge system. Either one can be connected to the gauge system
or to another module, allowing several units to be daisy chained together. Do not connect the I/O port to anything other
than a Dakota Digital gauge or BIM. Do not mount the module in the engine compartment; it should be mounted in interior
of the vehicle. Make sure the module is securely mounted and not hanging loose. It uses an internal acceleration
sensor which cannot accurately track the vehicle acceleration if it is loose.
The speed data does not use one of the 16 available bus ID’s like other Dakota Digital BIM units do. Speed data is
transmitted and updated every 0.1 second. The remaining data is sent one at a time in sequence along with any other
BIM modules present on the system.
The optional SEN-15 outside air temperature sensor can be connected when a Dakota Digital gauge system is connected
to provide a combination compass & air temperature readings together.
The GPS speed signal can be momentarily incorrect due to interference from overpasses, tunnels, and nearby structures.
To avoid this problem, the system stabilizes the speedometer reading by constantly comparing it with an internal
acceleration sensor. When the key is off, the system goes into a very low power standby mode and only occasionally
wakes up to update GPS readings so that it is ready to start operating as soon as the key is turned on.
The GPS-50-2 has an internal GPS antenna to directly receive GPS signals without the need for an external antenna. An
external antenna can optionally be added to enhance reception if the GPS-50-2 is mounted where GPS signals cannot
reach it. Contact Dakota Digital for part number and availability.

1 MAN #650519:B

Initial setup

Once the module is mounted securely and wired, there are a few internal tasks the GPS module will complete on its own.
First, the module needs time to acquire and track the satellites. This typically won’t work inside a steel building, so have
the vehicle outside to speed up the process. There is a dot in the upper right of the display that will be on steady or on
and flashing any time the key is on. The dot in the top center of the display will be on steady once it has gotten a GPS
satellite fix. The unit won’t operate until it gets a fix and this may take 1 – 15 minutes depending on various things. This
delay is only for the initial GPS fix. After this it will typically begin operating within a few seconds of turning the key on.
The second step is to let the internal acceleration sensor learn how it is mounted in the vehicle. You can mount it
securely in any position you want. When you are sitting still it learns which way is up. In order to learn which way is the
front of the vehicle you need to accelerate or decelerate on a straight stretch of road. Accelerate or decelerate for at least

2.5 seconds and make sure your speed changes by at least 10 mph. This procedure only needs to be done initially and
doesn’t need to be repeated unless you move the module to a different mounting location.

If you move it to a new mounting location or a different vehicle, enter the setup menu and select the rst option to speed
up learning the new mounting position.

Dakota Digital display data usage
The speed outputs can each be used in place of a separate transmission connection to the gauge control unit. The clock
is based on the accurate GPS time and only the hours need to be set to match it to your time zone. The compass
requires no setup or calibration for the vehicle and is accurate any time the vehicle is moving. The altimeter is calculated
from the GPS position data to give your current elevation. Each of these can be individually turned on or off.
The compass and altimeter may not display correctly unless the gauge control has the following firmware version or
higher:
VFD3: SE46

VFD3X: SE55
VHX: C VX04.009 (control box firmware must end in “.009” or higher)
D V***.006 (display firmware must end in “.006” or higher)

The compass, clock, and altimeter will be displayed in the message center.

Using speed from the GPS-50-2 without a BIM-01-x connected

• Make sure the BIM units are all connected to the gauge control box with the supplied BIM power/data cables.

• Hold the SW1 switch from the gauge system control box while turning the key on. The message display should

show SETUP.

• Release SW1. The message display should show SPEED.

• Press and hold SW1. The message display should show SENDER. Release SW1.

• Press and release SW1 until BUS is displayed.

• Press and release SW1 until DONE is displayed.

• Turn the key off.

• Next, press and hold the switch on the GPS-50-2 while turning the key on. The GPS-50-2 display should show

the current software revision.

• Release the switch. The display should show “-C-”.

• Press and hold the switch until “ - ” is displayed.

• Release the switch. The display should show “SPD”.

• Press and hold the switch until “ - ” is displayed.

• Release the switch. The display will show the current setting.

• Press and release the switch until “ON” is displayed.

• Press and hold the switch until “ - ” is displayed.

• Turn the key off.

2 MAN #650519:B

Using speed from the GPS-50-2 with a BIM-01-x connected

• Make sure the BIM units are all connected to the gauge control box with the supplied BIM power/data cables.

• Hold the SW1 switch from the gauge system control box while turning the key on. The message display should

show SETUP.

• Release SW1. The message display should show SPEED.

• Press and hold SW1. The message display should show SENDER. Release SW1.

• Press and release SW1 until NORMAL is displayed.

• Press and release SW1 until DONE is displayed.

• Turn the key off.

• Next, press and hold the switch on the GPS-50-2 while turning the key on. The GPS-50-2 display should show

the current software revision.

• Release the switch. The display should show ì-C-”.

• Press and hold the switch until “ - ” is displayed.

• Release the switch. The display should show “SPD”.

• Press and hold the switch until “ - ” is displayed.

• Release the switch. The display will show the current setting.

• Press and release the switch until “OFF” is displayed.

• Press and hold the switch until “ - ” is displayed.

• Turn the key off.

• Connect the GPS-50-2 SPEED 1 terminal to the gauge control box SPD SND terminal.

To set or change the GPS clock ID number and the time format:

• Hold the switch beside the GPS-50-2 terminal strip while turning the key on. The display will show the current
revision code while this is held.

• Release the switch. The display will show “-C-”.

• Press the switch and hold the switch until “ - ” is displayed.

• Release the switch. The BIM display will show “spd”.

• Press and release the switch until “ CL” is displayed.

• Press the switch and hold the switch until “ - ” is displayed.

• Release the switch. The display will show the current ID for the GPS clock.

• Press and release the switch to change the setting from 1-16 or OFF. OFF will prevent the GPS clock from being

displayed.

• Press and hold the switch to save the setting. The BIM display will show “12H” or “24H”.

• Release the switch. This is the current time format.

• Press and release the switch to change between 12 hour and 24 hour format.

• Press and hold the switch until “ - ” is displayed to save the settings.

• Turn the key off.

3 MAN #650519:B

The time is set up through the gauge display system.
Only VFD3/3X controls with a plastic case support adding BIM’s.
For VFD3, VFD3X, and VHX systems follow these steps:

• Make sure the BIM units are all connected to the gauge control box with the supplied BIM power/data cables.

• Hold the SW1 switch from the gauge system control box while turning the key on. The message display should

show SETUP.

• Release SW1.

• Press and release SW1 until BIM is shown on the message display.

• Press and hold SW1. The message display should show SCAN followed by the number of BIM channels

detected. Release SW1.

• If 0 is shown, check all connections and then press and hold SW1 with SCAN shown to retry reading the modules.

• Otherwise, if any other number is shown, press and release SW1 until SETUP is shown.

• Press and hold SW1 until the speed display shows “ – ” or the message changes.

• Release SW1. On the VFD3 systems the message display will show the label assigned to the channel and the

speed display will show “C” followed by the channel ID number. On the VHX systems the message display will
show “CH” followed by the channel ID number on one line and the label currently assigned on the second line.

• Press and release SW1 until the desired channel ID number is shown.

• Press and hold SW1. The message display will show “LABEL”.

• Release SW1. The message display will show “CLOCK”.

• The label cannot be changed. Press and hold SW1. The message display will show the current time.

• Release SW1. The message display will show the current time and the hours will flash.

• Press and release SW1 to change the hours.

• Press and hold SW1. On VFD3 systems the message display will now show “DONE” and the setup is finished.

On VHX systems the message display will show “USE AS MAIN” with “Y” or “N” highlighted.

• With VHX systems release the switch and then press and release the switch to select whether the main system
clock is read from the GPS-50 (Y) or the VHX internal clock (N).

• Press and hold SW1 until the display shows “DONE”.

• This can be repeated for additional channels, or the key can be turned off to exit setup.

To set or change the Compass or Altimeter ID number:

• Hold the switch beside the GPS-50-2 terminal strip while turning the key on. The display will show the current
revision code while this is held.

• Release the switch. The display will show “-C-”.

• Press the switch and hold the switch until “ - ” is displayed.

• Release the switch. The BIM display will show “spd”.

• Press and release the switch until “Cps” is displayed for compass or “ALT” for altimeter.

• Press the switch and hold the switch until “ - ” is displayed.

• Release the switch. The display will show the current ID for that reading.

• Press and release the switch to change the setting from 1-16 or OFF. OFF will prevent it from being displayed.

• Press and hold the switch until “ - ” is displayed to save the settings.

• Turn the key off.

4 MAN #650519:B

Using an electric speedometer with the GPS-50-2.

The speedometer signal input should be connected to either SPEED 1 or SPEED 2 depending on the speedometer
requirements. If you are unsure of which to use, start with SPEED 1 and then switch to SPEED 2 if it doesn’t work. You
can test the speedometer connection by entering the speedometer output setup described below. While you are at the
speed cal selection, the output will provide a 60mph signal for testing.
If you are going to be connecting a cruise control to the GPS-50-2, the CRUISE terminal provides an ECM style speed
output signal. The output rate for this terminal is the same as for the SPEED terminals. It is not uncommon for the raw
GPS speed data to vary by as much as 6 MPH when going under a large bridge or other structure. While this unit does
use additional sensors to monitor and remove this, it may be possible to feel the cruise change slightly even though your
speedometer will not show a change.

Speedometer output setup.

• Hold the switch beside the GPS-50-2 display while turning the key on. The display will show the current revision
code while this is held.

• Release the switch. The display will show “-C-”.

• Press and release the switch until “spd” is displayed.

• Press the switch and hold the switch until “ - ” is displayed.

• Release the switch. The display will show the current speed pulse setting, 4 for 4000, 8 for 8000, 16 for 16000, 54

for 54400, or 128 for 128000. It will also drive the output with a 60mph (96 km/h) speed signal so you can verify
the reading on your speedometer.

• Press and release the switch to change the setting.

• Press and hold the switch until “ - ” is displayed to save the settings.

• Turn the key off.

setup/status switch

Connect to main
chassis ground

+12V

(fused 5 - 20 AMP max)

CONSTANT BATTERY POWER

+12V

(fused 5 - 20 AMP max)

Standard speedometer output.

www.dakotadigital.com

KEY ON POWER

Connection for GPS
speed signal to other
electric speedometers.

GPS-50-2

GPS INTERFACE

ACC PWR

TEMP +

605-332-6513

GROUND

TEMP -

BATTERY

SPEED 2

SPEED 1

CRUISE

OPTIONAL
ANTENNA

BIM I/O

AC speedometer output.

Cruise control speed output.

5 MAN #650519:B

Setup Menu

-C- set BIM ID’s
SPD ON,OFF enable or disable speed data on BIM
CL 1-16,OFF set clock ID
CPS 1-16,OFF set compass ID
ALT 1-16,OFF set altimeter ID
END

spd 4,8,16,54,128 set or test the speedometer output calibration
CAL GPS/accelerometer override settings

Lo 0-130 Lowest speed accelerometer override is allowed, default setting should be used
AO1 0.3-1.6 GPS > accel, default setting should be used
AO2 0.3-1.6 accel > GPS, default setting should be used
UPD FST,SLO speed averaging update, default setting should be used

rst reset module orientation (relearn which direction is up and forward)
Snr signal to noise ratio readings for trouble shooting and diagnostics

xxH highest signal reading
xxL lowest signal reading
xx- average signal reading
xxn number of satellites being used
End exit setup

Cruise control operation with the GPS-50-2

While a transmission or wheel based speed signal is ideal for operating a cruise control, the GPS-50-2 can be used when
this is not available. Special care must be taken in selecting the mounting location for the GPS-50-2 so that it can get a
clear view of the satellites. The difference in mounting locations is not noticeable for a speedometer, but can affect the
precision operation of a cruise control system. Try to locate the GPS-50-2 as high as possible. It can be under a
fiberglass or wood dash or in a headliner. Avoid having the unit surrounded by steel. Another alternative to get an ideal
GPS satellite signal is to use an external GPS antenna. This can connect to the OPTIONAL ANTENNA jack on the top of
the GPS-50-2 and be used instead of the internal antenna. The small, external antenna can then be mounted in a
location to get a clear view of the satellites with the GPS-50-2 hidden under the dash.

The Snr setup menu will aid in selecting an acceptable mounting location. This should be done in a clear, outside area
and not inside a building. Hold the switch beside the GPS-50-2 terminal strip while turning the key on. The display will
show the current revision code while this is held. Release the switch. Press and release the switch until “snr” is
displayed. Press and hold the switch until “ - ” is displayed. Press and release the switch until “ n ” is displayed. It should
be tracking at least 6 satellites. If it is less than this wait a few minutes for it pick up additional satellites. Press and
release the switch until “ H ” is displayed. The maximum signal strength will be displayed in real time. You should try
different locations to obtain a reading of 40H or higher.

www.dakotadigital.com

605-332-6513

External GPS antenna connection for enhanced signal reception.

GPS

ACTIVE

ANTENNA

GPS-50-2

GPS INTERFACE

ACC PWR

GROUND

TEMP +

TEMP -

BATTERY

OPTIONAL
ANTENNA

BIM I/O

SPEED 2

SPEED 1

CRUISE

6 MAN #650519:B

Troubleshooting quick tips:

While the GPS-50-2 is operating, the dot in the upper left corner of the display will indicate the status. On steady
indicates it is powered up but not receiving any BIM bus activity. Flashing indicates it is communicating on the BIM bus.
A dot in the upper center indicates that it is receiving a valid GPS signal. A dot in the lower center indicates the
accelerometer is actively correcting the speedometer reading.
When the key is off the dot in the upper left corner will flash very slowly. If the switch on the GPS-50-2 is held, it will flash
rapidly indicating that the key is off.
To see the number of satellites being tracked, signal strength, speed, and heading on the GPS display, press and hold the

switch with the key on. It will toggle between displaying the number of satellites tracked followed by a dash (10-), the
signal strength followed by three dashes, current speed in km/h, and the heading in degrees.

Troubleshooting guide.

Problem Possible cause Solution
Sensor does not show on BATTERY terminal is not powered. Connect to a location that has power at all times.
gauge readout. ACC PWR terminal is not powered. Connect to a location that has power with the key on.
GPS will not light up at all. GND terminal does not have a good Connect to a different ground location.

Module is damaged. Return for service. (see instructions)
Sensor does not show on Interface cable is not connected. Connect the supplied power/data cable between the BIM unit and
gauge readout. the gauge control box.
GPS has a steady dot lit Interface cable is loose. Make sure both ends of the cable are seated in securely.
On VHX systems, the BIM display Follow instructions in VHX manual to enable the BIM display screen.
for this channel is disabled.
Another BIM is set with the same Test module works when connected to control box alone. Change ID’s
channel IDs. on one of the modules so each module uses unique IDs.
Sensor does not show on Another BIM is set with the same Test module works when connected to control box alone. Change ID’s
gauge readout. channel IDs. on one of the modules so each module uses unique ID’s.
GPS display is flashing
SPd, CL, CPS, or ALt (SPD – speed, CL – clock, CPS – compass, ALT – altimeter)
Speed always reads 0. GPS data is out-dated. If the constant power connection has been disconnected, it may take
GPS has a flashing dot in 5 – 15 minutes for it to get valid data from the satellites.
the upper left corner. GPS receiver cannot get a signal. If the car is inside a garage or other structure it may not be able to receive
a signal from the satellites. Move the vehicle to an open area and retest.
Speed always reads 0. Broken or loose wire connection. Inspect and reconnect wires.
SPEED terminal is used Wire connected to the wrong output. Switch between the #1 and #2 output types and retest.
for connection. Output calibration is incorrect. See “Speedometer output setup” in the manual.
Speed reading is incorrect. Speedometer output is set incorrectly. See “Speedometer output setup” in the manual.
Speedometer is not accurate. Consult your speedometer manual to determine the calibration steps.
Speed seems to lag or is Module is not mounted securely and is Mount the module securely using screws or hook and loop tape.
erratic. sliding around while driving.
The internal acceleration sensor needs Accelerate or decelerate in a straight line to allow the system to calibrate
to learn which direction is forward. itself.
Cruise control will not Speed output rate does not match. Change either the GPS-50-2 or cruise control speed pulse rate so they
engage. match each other.
Loose wire connection. Inspect wiring connections.
Cruise speed type is set incorrectly. Make sure the cruise control is set for an ECM type signal.
Cruise control will not Speed output rate does not match. Change either the GPS-50-2 or cruise control speed pulse rate so they
hold a steady speed. match each other.
Gain control on cruise incorrect. See cruise control manual to adjust gain or sensitivity.
GPS mounting location causing Move the GPS-50-2 to a new location to minimize signal reflections.

Speed signal wire is picking up noise. Isolate the speed signal wire from tachometer or motor wires.

ground.
RED wire on BIM-xx-1 adapter Connect to a location that has power with the key on.
harness is not powered.
BLACK wire on BIM-xx-1 adapter Connect to a solid vehicle ground location.
harness is not grounded.

degraded signal. Be sure to perform a reset after moving the unit.
Attach an external GPS antenna to the OPTIONAL ANTENNA jack
on the top of the GPS-50-2. The antenna can be secured to the
windshield or rear window for a clear view of the sky.

7 MAN #650519:B

GPS

-50-2

Specifications

SUPPLY VOLTAGE

Battery Power 6 to 22 V

Accessory Power 6 to 22 V

SPEED OUTPUTS

Update Rate 10 Hz

SPEED 1 Ground switching (1.4 A max)
SPEED 2 +/- 6V typical at 13V power

CRUISE Ground switching (0.3 A max)

CURRENT DRAW
Accessory On ≈ 39 mA
Accessory Off ≈ 4 mA

SERVICE AND REPAIR

DAKOTA DIGITAL offers complete service and repair of its product line. In addition, technical
consultation is available to help you work through any questions or problems you may be having installing one
of our products. Please read through the Troubleshooting Guide. There, you will find the solution to most
problems.

Should you ever need to send the unit back for repairs, please call our technical support line, (605) 332­6513, to request a Return Merchandise Authorization number. Package the product in a good quality box

along with plenty of packing material. Ship the product by UPS or insured Parcel Post. Be sure to include the
RMA number on the package, and include a complete description of the problem with RMA number, your full
name and address (street address preferred), and a telephone number where you can be reached during the
day. Any returns for warranty work must include a copy of the dated sales receipt from your place of purchase.
Send no money. We will bill you after repair.

Dakota Digital 24 Month Warranty

DAKOTA DIGITAL warrants to the ORIGINAL PURCHASER of this product that should it, under normal use and
condition, be proven defective in material or workmanship for the lifetime of the original vehicle it was installed in, such
defect(s) will be repaired or replaced at Dakota Digital’s option.

This warranty does not cover nor extend to damage to the vehicle’s systems, and does not cover diagnosis,
removal or reinstallation of the product. This Warranty does not apply to any product or part thereof which in the opinion of
the Company has been damaged through alteration, improper installation, mishandling, misuse, neglect, or accident.
Dakota Digital assumes no responsibility for loss of time, vehicle use, owner inconvenience nor related expenses.
Dakota Digital will cover the return standard freight once the product has been evaluated for warranty consideration,
however the incoming transportation is to be covered by the owner.

This Warranty is in lieu of all other expressed warranties or liabilities. Any implied warranties, including any
implied warranty of merchantability, shall be limited to the duration of this written warranty. No person or representative is
authorized to assume, for Dakota Digital, any liability other than expressed herein in connection with the sale of this
product.

WARNING: This product can expose you to chemicals including lead, which is known to the State of California to

cause cancer and birth defects or other reproductive harm. For more information go to www.P65Warnings.ca.gov

8 MAN #650519:B