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Project Honda Insight, Part 16 The digital dash

Lots of instruments and warnings

by Julian Edgar

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At a glance...

  • MoTeC CDL3 programmable digital dash
  • MoTeC SLM programmable LED module
  • Installing the dash
  • Gauges
  • Custom warnings
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This series is based around a 2001 model hybrid Honda Insight.

The Insight remains one of the most aerodynamic and lightest cars ever made, with a Cd of 0.25 and a total mass of about 850kg from its 2-seater aluminium body.

The intent of the project is to turbocharge the engine, add water/air intercooling and programmable engine management, and then provide new high voltage batteries and a new electric motor control system.

The aim is to build a car with the best performance/economy compromise of any in the world.

The series so far:

Project Honda Insight, Part 1 – Introduction

Project Honda Insight, Part 2 – Fitting an Alternator

Project Honda Insight, Part 3 – Building an Airbox

Project Honda Insight, Part 4 – Intercooling Requirements

Project Honda Insight, Part 5 – Intercooling System #1

Project Honda Insight, Part 6 – Intercooling System #2

Project Honda Insight, Part 7 - Turbocharging

Project Honda Insight, Part 8 - Building the Exhaust

Project Honda Insight, Part 9 - First Electricals

Project Honda Insight, Part 10 - Alternator (again!) and beginning the MoTeC wiring

Project Honda Insight, Part 11 - New ignition system and cam sensing

Project Honda Insight, Part 12 - The MoTeC CRIP

Project Honda Insight, Part 13 - Idle Speed Control

Project Honda Insight, Part 14 – First road tuning of the MoTeC

Project Honda Insight, Part 15 - Refining the on-road tune

This issue: the dash

Not covered until now, but actually installed at the same time as the ECU, was the MoTeC CDL3 digital dash.

The MoTeC CDL3

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The MoTeC CDL3 is one of the older range of MoTeC dashes – these are able to be identified by their B&W LCD and arched upper shape. These dashes are less configurable than the current colour square-shaped MoTeC dashes but from my perspective, have a major advantage – the shape of the dash means it can be fitted within the standard Honda Insight dash binnacle.

The backlit CDL3 has a 70 segment bar graph (normally used to show engine revs), central large number (normally used to show selected gear), three numerical displays, and a programmable lower line that can be switched between many different inputs to show other data on demand. This lower line is also used to display warning messages.

There are also three dash ‘pages’ that can be chosen – that is, the dash as a whole has three different screens, with each able to be configured separately.

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The CDL3 (optionally) comes with 4 analog voltage inputs, 2 analog temp inputs, 2 digital inputs, 3 speed inputs and 4 PWM or switched outputs. Internally, it runs a 3-axis accelerometer.

It is able to accept RS232 and CAN communications. Laptop communication with the dash is via an Ethernet cable.

The dash is able to receive data from the ECU via the CAN bus. In my case, where the MoTeC M400 is being used, this substantially reduced the number of inputs the dash itself needed to have. This is because all the inputs to the ECU (MAP, coolant temp, throttle position, etc) can be displayed on the dash via the CAN bus.

The CDL3 I bought was second-hand and came with the optional input/output upgrade and a GPS sensor. I purchased the CDL3 track logging kit upgrade loom, the two-pushbutton loom (that includes the buttons), and the input/output upgrade loom. This allowed me to plug in the GPS sensor and the two pushbuttons (used to control dash functions). I subsequently bought an SLM multi-function LED display (covered in a moment) that also plugged straight into this new loom.

Like much MoTeC stuff, all the information about these upgrades is available – but you need to search hard to find it. I found using Google better than trying to find it on the MoTeC site itself. Note that with some digging, MoTeC support for older products is very good – helping to explain why second-hand MoTeC gear still commands good prices.


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The MoTeC Shift Light Module (SLM) comprises a small unit housing 8 LEDs. Much more than a shift light, each of these LEDs can be separately configured via the CAN bus for colour and intensity. (Note that there is also a cheaper SLM-C version that has single colour LEDs.)

The SLM allows different driver warnings to be indicated with different colours and LED positions. Static and flashing modes can be configured.

The main advantage of the SLM is that it doesn’t use up any outputs from the ECU or dash. In my application, where the dash has four switched outputs, these would have all been used in triggering four warning lights – eg fuel, shift, oil pressure and lean condition. With the SLM, these warnings - and dozens of others – can be configured as required, using the CAN bus and so with no dash or ECU outputs utilised.

While initially I thought the SLM a bit of an extravagance, it has become an integral part of how I use the dash.

The new MoTeC parts were purchased from


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As with the MoTeC engine management software, starting from scratch and becoming proficient in the dash software took me many, many hours. That said, in many ways the dash software is easier than the ECU software, so it’s a good place to start!

I initially set the dash up on the bench and, using just a few inputs (GPS and a pot on an analog input), played with the software until I was able to get these signals displayed on the dash.

That successful, I was then confident enough to install the dash in the car.

Installing the dash

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The CDL3 was mounted on a carbon fibre sheet cut to shape. The carbon fibre panel was sourced from the UK via eBay. An A3-sized, 3mm thick single-layer sheet, it cost about AUD$100 by the time it got to Australia. By ‘single layer’, the description means that most of the sheet comprises glass fibre; the carbon fibre is just the top layer.

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The panel was masked and marked out for the required holes. Holes were drilled in a drill press, starting with small drill bits and working upwards in size. A hole-saw was used to make larger diameter holes. Cutting of the panel was achieved with a thin 1mm cutting disc in an angle grinder.

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Six millimetre threaded rod was used to provide the mounting pots for the new panel. These rods screwed (via nuts and washers) into the original mounting holes of the dash but allowed the location and angle of the new panel to be adjusted as required.

The plastic dash binnacle required extensive reshaping of its shroud to fit flush against the newly positioned panel.

Surface finish

The surface finish of most carbon fibre sheet is very glossy: often too glossy for a dash panel.

To reduce the gloss, I buffed the dash panel gently with a Scotchbrite belt in a belt sander, then followed this up with hand work in a circular motion with fine steel wool, followed by three applications of ‘rejuvenating’ car polish and a final buff with a soft cloth.

This gave a relatively dull finish but one where the carbon fibre weave was still quite prominent.

The two pushbuttons were mounted low on the dash (these select ‘page’ and ‘alarm acknowledge’) while I added another input that utilises the standard Honda FCD button mounted high on the dash. This FCD button scrolls through the lower line of text on the dash, allowing the showing of driver-selected data.

Warning lights

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While the SLM can provide multiple warning light displays, some LED warning lights were also needed on the dash panel itself. These include left/right indicator, low/high beam headlights, handbrake/brake system failure, and a red warning that will become the alarm flasher.

After looking very hard all over the world, I chose to use Black Bezel LED warning lights from car Builder Solutions in the UK. (See These LEDs incorporate a dropping resistor, so can be connected straight to 12V.

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Note that despite being quite expensive, the warning lights aren’t perfect. In the high beam warning light, the internal display would rotate unless the rear was held in position with some hot melt glue (as shown here).

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The high beam light proved to be too bright, so a 20K pot was wired in series and adjusted until the required intensity was achieved.

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The wiring for the warning lights connects to the car loom vi a 12-pin Deutsch connector.


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The dash can be configured in literally hundreds of ways. During tuning of the engine management system, I often changed the data coming up on the dash. For example, when tuning the action of the intercooler water pump speed, I brought this aux output duty cycle up on the dash.

So rather than describe a final configuration (there probably will never be one!), here are some of the ways in which the dash is being used:

  • Engine RPM

Engine rpm is displayed on the bar graph, with the signal coming from the ECU via the CAN bus.

  • Speed

Road speed is displayed in two different ways. The speed input from the gearbox to the ECU is shown on the dash (via the CAN bus), and the speed sensed by the GPS plugged into the dash (RS232 communication) is also shown. Initially, when calibrating the gearbox speed input, I brought up both displays side-by-side and then changed the calibration number until the two matched.

  • Gear

The selected gear (1 through to 5 plus neutral) is calculated by the dash using speed and rpm inputs (both sent from the ECU). This works surprisingly well on the road – with the settings carefully tuned, the displayed number changes as soon as the gear is selected and the clutch pulled out. (Note that reverse gear is shown as ‘1’ on the dash!)

  • Fuel Level

Fuel level is displayed using the input of the factory Honda sensor. The resistive sensor connects to an AT (normally temperature) input on the dash. Fuel level is displayed as 0-100 per cent, with the relationship between sensor resistance and percentage display calibrated in the dash software.

  • Engine temp

Engine coolant temp is displayed in degrees C, sent from the ECU via the CAN bus.

  • Lambda number

Lambda (a way of expressing the air/fuel ratio) values are shown, with these sent from the ECU via the CAN bus.


Also able to brought up by pressing the FCD button is the following data, all sent from the ECU and shown on the bottom line of the display:

  • Manifold pressure

  • Inlet air temp

  • Fuel injector duty cycle

  • Engine oil pressure

  • Engine oil temperature

  • Ignition advance

  • EGR valve duty cycle

  • Water/air intercooler pump duty cycle

  • VTEC on/off

  • Lambda short term trim

  • Lambda long term trim


There are warnings (text displayed on the dash and specific SLM LED configuration activated) for the following:

Displayed Warning

SLM configuration



8 yellow/black flashing at fast rate

Gear change redline indicator


8 red

Uses standard seatbelt buckle switch + speed over 5 km/h

Door open

8 red

Door switch + speed over 5 km/h

Engine hot

8 red

Engine over 100 degrees C for more than 5 seconds

Oil pressure

8 red

Configured on minimum pressure at 1000+ rpm


8 red

Manifold pressure above 150 kPa and Lambda is 1 or higher

Battery level

2 yellow

Less than 12V for more than 5 seconds, uses internal dash battery voltage monitoring

Inlet air temp

2 yellow

Over 50 degrees C

Fuel level

2 yellow

Less than 10 per cent for more than 10 seconds

Change up

2 blue

A higher gear should be selected for best fuel economy. Based on throttle position and manifold pressure and gear and engine rpm.

Change down

2 purple

A lower gear should be selected. Based on throttle position and engine rpm.

ECU hot


Uses existing internal temp sensor

Dash hot


Uses existing internal temp sensor


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While the learning curve required to program the dash was immense, the end result looks fantastic and works very well.

So what doesn’t the CDL3 do?

Maths functions!

And the more I wanted the dash to perform different functions, the more I wanted access to those maths calculations.

So when I found an ADL3 for sale, brand new but being sold as a used item, I grabbed it. Looks the same as the CDL3, but can do vastly more…

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