How a Haltech dash gets its data
A Haltech display dash doesn't measure much on its own. Mostly it listens to a CAN bus and draws whatever arrives. That's why the first job on any dash install is telling it which "language" to listen for. In NSP there are three CAN options, plus the dash's own physical inputs for anything you'd rather wire directly.
Everything below assumes your dash is configured with NSP. Older iC-7 units that still run the ICC software need updating first, which we cover in updating an iC-7 to NSP. If you're new to the dash layout in NSP, start with navigating dashes in NSP.
| Data source | Use it when | Key NSP settings |
|---|---|---|
| Haltech CAN | The car runs a current Haltech ECU | Haltech CAN Bus on in Connections, CAN port set to Haltech CAN Bus Port 1, same setting on the ECU |
| OBDII CAN | A factory ECU with CAN-based OBDII | Third Party CAN Bus on, CAN Bus Port 1, protocol set to OBDII |
| Third-party ECU | A supported aftermarket ECU from another brand | CAN Bus Port 1, your ECU chosen under Third Party CAN, extra channels as generic CAN channels |
| Direct inputs | A signal wired into the dash's main connector | Enable the matching function (Tacho Input, Vehicle Speed, Indicators) and assign the input |
Reading a Haltech ECU
Most dashes leave the box already set up for this, so you'll usually only do it if you've loaded a different configuration. It takes two passes, one with the dash connected to NSP and one with the ECU.
- Connect the dash to NSP and switch on the Haltech CAN Bus setting under Connections.
- Open the CAN sub-node and assign the dash's port to Haltech CAN Bus Port 1.
- If the dash is the last device on the bus, enable its terminating resistor.
- Disconnect the dash, connect the ECU, and enable Haltech CAN Bus under Connections there too.
- Assign the ECU's CAN port. Most Haltech ECUs have more than one, so pick the port your dash is physically wired to.
That's all a dash needs to display ECU data. If you also want to share inputs and outputs between the two, for example using a dash input to trigger an ECU function, follow IO between dash and ECU in NSP.
Reading a factory car over OBDII
This is the one to use when a dash goes into a car that keeps its factory ECU, provided that ECU speaks CAN-based OBDII.
- Power the dash through the HT-135003 OBDII to CAN cable and connect it to NSP.
- Under Connections, enable Third Party CAN Bus.
- In the CAN sub-node, set the port to CAN Bus Port 1.
- Click Third Party CAN (Connections > CAN) and choose OBDII as the protocol.
Most CAN OBDII cars will then give you engine speed, manifold pressure, throttle position, coolant and intake air temperature, vehicle speed, and short and long term fuel trims, among others. Exactly what's available depends on the car. Our OBDII channel list shows the full set. The iC-7 OBD-II kit bundles the dash with this setup in mind.
Reading another brand of ECU
Haltech dashes support a list of aftermarket ECUs from other brands. The setup mirrors the steps above:
- With the dash connected to NSP, turn on the CAN bus setting under Connections.
- Assign the dash's port to CAN Bus Port 1, and enable the terminating resistor if the dash ends the bus.
- Under Connections > CAN > Third Party CAN, pick your ECU from the list.
Each supported protocol also carries extra channels beyond the standard set. To use them, map each one into a Generic CAN channel assignment in NSP. Once mapped, generic channels drop onto gauges, bars and warnings just like the built-in ones. We have brand-specific guides for Hondata K-Pro, Link, MoTeC, MaxxECU and Syvecs that cover the ECU side of each.
Wiring signals straight into the dash
Sometimes a channel shouldn't come over CAN at all. Maybe the ECU doesn't broadcast it, or you're running the dash on a car with no compatible ECU. Here are the three direct inputs we set up most often.
Tachometer
Out of the box, RPM is read from CAN. To use a tach wire instead, enable Tacho Input under Sensors. The dash will then read its tacho pin, and you calibrate it by choosing your engine's cylinder count. If the RPM reads double or half what it should, the cylinder setting is the first thing we check.
Vehicle speed
Speed also defaults to CAN. Enable the Vehicle Speed function and assign it to a dash DPI or SPI to read a wired sensor instead. A common way to get a clean speed signal on a swap is the Haltech GPS speed module, wired to one of the dash's DPIs, which avoids hunting for a working factory speed sensor.
Indicators, high beam and warning lights
By default the dash expects the turn signals, high beam, park lights and handbrake warning to be wired to its own inputs. If those lights are switched by a Haltech ECU or PDM instead, turn off the Indicators and Headlights functions in the dash configuration. The dash will then take their on/off state from CAN and flash the icons on screen to match.
Troubleshooting
| Symptom | Usually |
|---|---|
| Dash shows no ECU data at all | CAN bus not enabled on one side, wrong port assigned on the ECU, or CAN High/Low swapped |
| Data drops in and out | Termination missing or doubled. The bus needs a resistor at each end, and only there |
| OBDII shows only some channels | The factory ECU doesn't support every PID; check the supported list |
| Third-party ECU extra channels missing | They haven't been mapped into generic CAN channels yet |
| RPM reads wrong on a wired tach | Cylinder count set incorrectly under Tacho Input |
| Indicator icons never light | Indicators/Headlights functions still set for direct wiring while the ECU or PDM is switching the lights |
FAQ
Can a Haltech dash work without a Haltech ECU?
Yes. It can read a factory ECU over CAN OBDII, a supported third-party ECU, or its own wired inputs.
Do I need to set anything on the Haltech ECU as well as the dash?
Yes. Both devices need the Haltech CAN bus enabled, and the ECU needs the correct port assigned for where the dash is wired.
Can I mix CAN data and direct inputs?
Yes. Each channel has its own source, so you can read most data from CAN and still wire, say, a tach or speed signal directly. For help with a mixed setup, get in touch.
