Fiesta XR4 Drive-by-Wire Cruise Control

[Aaron]

I’ve had this unit installed on the car long enough now to know some of the foibles and some of the wins.

So it’s a long time coming for this guide.

I sourced the unit from CANM8 in the UK, it was about AUD380 delivered and was ordered to suit a Fiesta ST150 (aka XR4). You can find them on the web, www.CanM8.com

Now on with the show!

First I’ve picked up some OEM pedal connectors so I can make this a plug and play install - so when/if the unit fails it can be taken out of the pedal circuit quickly. Lukeyson needs the credit for finding these: https://a.aliexpress.com/_m02UuUK I ordered a male-female pair obviously!


Step One; check the connector pairs I have plug into the loom and the pedal.


Step Two; make the cable. All it really takes is the 4 wires to go to/from the cruise unit and the others to be directly connected.

I was less worried about patching in the CANBUS, Brake and Clutch wiring because realistically they’re just inputs to the Cruise unit not impacting the function of the car whether connected or not. The pedal signal is different, if for some reason the cruise module breaks the circuit well, yeah, no go pedal for you!

Some suppliers of cruise kits supply this loom completely plug and play. So there shouldn’t be a technical issue as long as the connectors and crimps are OK

Finalising the install is a bit of a different matter.

There were only 4 wires to solder in, an earth and a hole to drill for the stalk, how hard could that be?

Turns out 4 hours of cut hands, minor burns and a enriched swear jar because someone in the factory pinned one connector differently.

First step was to pull off the lower dash trim.


It was at this point I decided that the stereo wiring bundle I’ve ignored for close to 15 months needed some little work.


So it got wrapped all the way down to the B-pillar and ultimately tucked around the factory looms a bit better. The green connector incidentally is where I have to splice in the dimming control for the instrument cluster, but that’s for another day.



Next the cruise wiring starts. First the pedal interface and power harness are spliced in. The instructions are pretty good, and show the connector pins that need to be tapped. The unit is powered from the brake light feed, ground is a factory chassis ground on the a-pillar frame.

The clutch switch gets tapped, but thanks to the switch location and cost effective wiring loom it’s almost inaccessible. Soldering the splice up there was a lesson in hot things in confined spaces.

Overall the wiring plan was to bring all the elements of the cruise wiring into a single wrapped bundle then the unit mounted.


The stalk gets mounted to the lower column trim. There’s realistically one place it can go but with the weird angled offset attachment the way the stalk “points” has quite a bit of adjustment.

I set it well back so that it’s out of the way of the indicator stalk, but there’s enough finger room to hit the cancel button on the rear or operate the cruise without dashing the dash either.


In place. I tried to make it “factory like” by being as parallel to the indicator stalk as possible.

In practice from my driving position the indicator lamp is just visible over the left hand spoke of the steering wheel, but the control itself is readily operable without interfering with or be obscured by the other stalks. I call that a win.

The last step was to power it all up and run the diagnostics, before a long awaited test drive.

The instructions are a bit like “Turn on IGN, within two seconds press and hold the “on” button u til the LED lights Red”. It was a bit disappointing when it didn’t.

Following a hunch that the unit wasn’t getting power I tried to enter Diagnostic mode while holding the brake pedal. Success! Obviously I had tapped the downstream side of the brake switch. Oh well, probably should have read the instructions. However I had wired it as per instructions. So it was obviously “the other right hand side wire when viewed from the wire side”. The wire colour is the same on each side so maybe I should have actually checked with a meter first. Swapped than around and tried again.

Passed all diagnostics except the Brake detection.

Look down and realise I hadn’t plugged the pedal switch in. Plug it in and try again.

Success!

Clean up the tools and go for a drive.

It worked!

I’m pretty happy with it, performance (smoothness of engagement, disengagement etc) is no different the factory cruise in other DBW cars and miles better than the old school aftermarket stuff.

[Aaron]

Now some foibles:
- Occasional logging errors; not the kind that turn on any warning lights, but the kind that indicate sometimes the cruise unit is doing a bit of a break before make on the accelerator signal. Probably on disengagement under some circumstance.
- Speed Limiter vs Cruise and the two “saved speeds”. The control stalk is a touch fiddly, so the two toggle like switches to engage the system or select the saved set-speeds can sometimes result in nothing happening, or worse (in my opinion) accidently reprogramming the stored set speeds!

Overall though, another modification that makes the car far more day to day useable - I’ve enjoyed having cruise on longer highway runs of course, but even around Canberra there’s more than enough stretches where tapping the cruise on and not worrying about tickets is nice.

It’s also worth noting that the short gearing and torque of the 2.0 motor mean that hills etc are dispatched with no fuss at highway speed, although as the cruise doesn’t see engine lid increasing it can drop 2-4km/h before it starts feeding on the throttle to deal with larger hills. That doesn’t worry me given my foot often has a similar variance of distance.

[SaxonD]

amazing. Thanks its the one feature that I really longed for with mine. That and a slightly softer clutch for city driving