14CUX ECU diagnostic info

[Tobs]

Hi,

I was wondering if anyone had some info on the Lucas 14CUX ecu? I'm mainly after protocol information about the diagnostics functions available from the ECU.

If I can get the required info then I maybe looking to develop a cheap code reader / diagnosics device for a laptop. I am aware that there is more info available such as real time sensor readouts than the basic available (on board diagnostic code reader) can give.

Toby.

[GreenV8S]

Somebody at PH has a fault code reader available to rent, and I seem to remember Mark Adams saying he was thinking about making a fault code reader/live sensor display.

[rfisher]

GreenV8S said:

Somebody at PH has a fault code reader available to rent, and I seem to remember Mark Adams saying he was thinking about making a fault code reader/live sensor display.

Yes - that's me.

www.pistonheads.com/sales/64328.htm

If you hire it just don't take it to bits for a bit of 'reverse engineering'

[shpub]

Many have tried but no one has done it yet. The information is not in the public domain and never been released. It is possible to buy more sophisticated readers for around £4-500 but at that price buying a fully programmable ECU starts to become cost effective with all the software already included.

[Plotloss]

RPi sell the Rovercom...

Also, if its OBDII compliant, there are loads of readers already out there.

Writing may be a different matter though.

[rfisher]

Plotloss said:

RPi sell the Rovercom... Also, if its OBDII compliant, there are loads of readers already out there. Writing may be a different matter though.

Rovercom is well expensive (£1000's).

14CUX is not OBDII or OBDI.

Actually, buying a fault code reader and taking it apart is not a bad idea. I've never taken mine apart (they are sealed units) but chances are that there's only 1 or 2 chips in it. I reckon all it does is read a single 8 bit chip buffer.

Of course, you'll need to find one for sale and there 'ain't a lot of them about these days.

[Plotloss]

On the RPi website Rovercom Lite is about £500

It also says OBDii

Its the same with Vauxhalls, a TechII is about £4500

A bluetooth OBDii reader and the software was £150

Get live data off the ECU, lovely.

>> Edited by Plotloss on Monday 13th February 19:43

[Tobs]

Yes, there are devices out there that do what I had in mind, however they are either very expensive (the cheapest is the ROVACOM LITE, which works oout at about £400-£500 inc VAt for the complete kit), or they are quite basic, i.e. the "Fault Code Display Unit" (PRC7067) (which are no-longer available)

As Steve said above, getting hold of the communications protocol info is the hard part, actually making the hardware / writing the software is the easy bit! (I'm an Electronics design engineer)

After a bit of trawling on the net I've found out that the protocol used is based on ISO 9141-1. However I think this only defines the voltage levels used and not the packet data (maybe this is similar to OBD2??)

Reverse engineering one of the basic fault code display units may be the way to start I just need to find one for sale now!

EDITED TO ADD:

Thinking about it, the basic fault code display is not connected to the diagnostics connecter at all (this is the connector with a ground loopback wire going into it) whereas the basic code display connects to a square 4-pin connector also on the loom. So reverse engineering this may not be useful....



Toby.


>> Edited by Tobs on Monday 13th February 20:51