WQ Fiesta XR4 Diagnostics/OBD2 Reverse Engineering

[Luke Plaizier]

There's a few different Arudino models I thought. Some of them with more CPU grunt thans others, if you were having issues with yours being overloaded. I have been reading with interest the Speeduino project for example, and wondering if I should weld up an engine stand and put one of the spare engine's I'm pulling out on it and see if i can get it to run on a Speeduino.

A project for a time in the future perhaps, lest I load myself up with too many things and take myself too far off track, but I would find it interesting - especially if your efforts in understanding the IC might work out to be relevant. Speeduino seems to have the bulk of it's R&D done on an NA/NB Mazda Miata/MX5 engine. If by any chance they do an NC MX5 we should pay attention, since that engine is essentially the same as in the XR4....


Luke

[Aaron]

Well the read and rewrite Arduino setup is working quite well. I’m piecing together the code extensions to make about 10-15 “semi useful” parameters able to be displayed on the cluster.

And extension of all this is another project where I will be using an Arduino to inject data onto the bus mimicking the VSS (road speed) data that the ABS module provides along with extracting out some other things.

I’ve also extracted the EEPROM PATS data from the cluster starting to work out how the interchange of PATS messages with the ECU is both triggered and followed up on.

[Luke Plaizier]

Ooh, so you have an EEPROM reader/writer? The BA/BF Falcon cluster required an eeprom rewrite to be able to reset the cluster back to 0km. I wonder if the WQ cluster is the same?

The guy that did that at the time used be here on AFF. It's been a few years, I'm not sure if he's still around. If he is, look for auMatt.


Lukeyson

[FairmontGS]

Luke, can you recommend a Forscan setup that I can use with my WT LX? I have the hardware in place for the fog lamp enablement.

USB or Bluetooth?

https://www.ebay.com.au/sch/i.html?_...Desc=0&_sop=12

[Aaron]

Originally Posted by FairmontGS

Luke, can you recommend a Forscan setup that I can use with my WT LX? I have the hardware in place for the fog lamp enablement.

USB or Bluetooth?

https://www.ebay.com.au/sch/i.html?_...Desc=0&_sop=12

I use the Forscan recommended OBDlink EX.
OBDLink EX https://www.amazon.com.au/dp/B081VQV...C1Y2C6EMAFZJW4

Price has gone up a stack since I bought (for about $80 in December).

What I like is “it just works” no flipping switches, no “it is too Chinabay special” etc and there is some recognition between OBDLink and the developers of Forscan which most of these eBay ones don’t have.

[Luke Plaizier]

I recall a 'recommended tool list' on the Forscan sites. For some activities the USB tools are preferred because they provide a faster and more reliable link when doing module programming. So in general USB is preferred - but Bluetooth is likely to be OK these days at a close distance. Both present a serial interface to the software you are using so will be limited by the implemented serial baud rates.

https://forscan.org/forum/viewtopic.php?t=6142

Forscan supports a few tools though. I have some tools that support the J2534 API and can confirm it works for those as well. J2534 is a pretty robust standard now. I have a few different tools that support J2534 and when I load up a J2534 driver for them it will then work with software that has J2534 support - such as licensed versions of Forscan or the Motorcraft IDS software for Ford. Actually most OEM diagnostics software are written to support J2534 these days as the US EPA mandated J2534 support around 2004 I think.

You won't go wrong with an OBDLink device. Reliable and great support.

But I also have one of these and it does everything I need it to do, i just have to manually switch between the HSCAN (PCM, Cluster) and the MSCAN (Radio, GEM other modules we don't get like climate control and speech recognition). The Airbag and ABS module answer on a 3rd communications bus called ISO9141 - which these tools can access as well.

https://www.ebay.com.au/itm/31358730...kAAOSwVSBg3YbG



Lukeyson

[Aaron]

Ahhh, not quite EEPROM but some enterprising folk worked out how to brute force the change to the EEPROM on both the ECU and the Cluster.

It can also rewrite the odometer.

What it also does is correctly rewrite the odometer increment pattern so it doesn’t show faults, it does it on the ECU and the Cluster as well so the pair can be reset. It’s a neat piece of software and critical to my ongoing “I can fix busted instrument clusters” objective.

[Luke Plaizier]

Do tell more.

Lukeyson

[Aaron]

So I’ve been running a few Duratecs “stand alone” with just the XR4 ECU,
Paired Cluster and obviously a key reader and Accel pedal.

It feels like 2007 all over again when I did this with a Focus set up.

The XR4 setup does have more potential “down the line” and now I’m working on the various bits of messaging needed to make the ECU “more happy” about not having modules connected. It doesn’t actually generate a MIL and the engines run correctly but without a valid speed input the torque mapping is a little less good.

As it turns out it misses its friend the BCM and well as the ABS module (that’s quite obvious because that’s where road speed comes from).

For these standalone builds I’ve started working on a microcontroller that lives on the CANBUS and injects the messages needed to give some peace of mind to the ECU. Using GPS for the speed data and so on.

On these the standalones we use either discreet instruments OR a Haltec IC7 or similar.

I still haven’t bothered much more with the PATS side of things.

[FeistyFiesta]

Hey guys, interesting thread.. the canbus stuff is beyond me.

Any developments? Are you guys still playing with your WP/WQ/XR4 Fiestas?