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NEXUS R3 CONNECTIONS
25A High Current Outputs
High current outputs 25A-HCO1 and 25A-HCO2 are
allocated in this harness for injector and ignition
+12V sources respectively.
Two spare 25A high current outputs, 25A-HCO3
and 25-HCO4, are available to control high
current devices such as fuel pumps, thermo fans,
transbrake solenoids, etc.
These outputs have automatic high and low side
overcurrent and undervoltage lockout protection
and are PWM capable as well.
Specs:
• Number of channels: 4
• 25A source or sink current output
• Automatic high and low side overcurrent
and undervoltage lockout protection
• 0 to 30V feedback
• High and low side current feedback
• 1kHz switching speed
• Capable of 0-100% duty cycle
25A-HCO 3
25A-HCO 4
25A-HCO 1
25A-HCO 2
(INJ +12V)
(IGN +12V)
+
-
25A-HCO 3
Example of a 25A-HCO controlling a high current
device such as a fuel pump.
Half Bridge Outputs
Half bridge outputs are push-pull pulse width
modulated outputs that can be used to control
stepper motors, DBW throttle motors, or electronic
wastegates.
HBOs can also be used to provide 12V 8A power to
high-side driven devices such as VTEC solenoids
or high-side switched automatic transmission
solenoids.
The Nexus R3 universal harness is fitted with six
HBO wires with the last two allocated to provide
power to the CAN plug, sensors, and other devices.
Specs
:
• Number of channels: 6
• 8A to 12V (high), or 8A to ground (low) output
• 5A max when used as push-pull PWM (eg DBW)
• Automatic overcurrent and overtemperature
protection
• 0 to 27V feedback
• High side current feedback
• 18kHz switching speed in DBW mode
Unused HBOs can be used as:
• Generic push/pull 2.2kHz PWM output
Note: Half bridge output HBO 5 and HBO 6 are
allocated in this harness to provide power for CAN
devices, cam and crank sensors, and SPI/DPO
power connections. Ensure these HBOs are set as
engine control relay outputs in your VCU map so
they provide power when the VCU is On.
HBO 1
HBO 2
HBO 3
HBO 4
HBO 5
HBO 6
(+12V for CAN, TRIG, HOME)
(+12V for SPIs, DPOs)
In-cabin connections
The Nexus R3 universal wire in harness has
multiple input and output wires allocated for
in-cabin connections. This group of in-cabin wires
are labelled and grouped together with power and
ground sources to make it easy to wire in sensors,
switches, relays or other devices.
Refer to the diagram below for the available
connections. Unused wires can be reallocated to the
engine bay to suit the application.
+5V
AVI 8
SIGNAL
GROUND
+5V
AVI 9
SIGNAL
GROUND
ANALOGUE VOLTAGE INPUTS
+5V
+12V
SIGNAL
GROUND
SPI 5
SIGNAL
GROUND
(HBO 6)
SPI 6
SYNCHRONISED PULSED INPUTS
+12V
DPO 1
(HBO 6)
DIGITAL PULSED OUTPUTS
+12V
DPO 2
(HBO 6)
+12V
DPO 3
(HBO 6)
TCA8
KEYPAD
CAN
HUB
iC-7 DASH
TMS4
CAN
HUB
CAN 1
IN-CABIN
CAN 2
IN-CABIN
CAN 1
ENGINE BAY
CAN 2
SUPPORTED OEM
CAN PROTOCOL
(OPTIONAL)
Haltech CAN connection
(Label: CAN 1 and CAN 2)
This harness is fitted with two CAN channels that
you can use with a range of Haltech CAN expansion
devices (displays, keypads, TMS4, etc.) or integrate
to a supported factory CAN system.
Three DTM-4 CAN plugs are available with CAN 1
and CAN 2 in-cabin connections, and another CAN 1
connection extended to the engine bay side.
Specs:
• Supports CAN speeds up to 1 Mbit/s
• Selectable 120ohm termination resistor
per CAN channel
• Supports all Haltech CAN expansion products
• Selectable preconfigured vehicle CAN interface
(OBDII compliant)
