Canbus converter for ECU install??????

[TERRA Operative]

I'm looking at installing an adaptronic ECU into a Jeep running a canbus system.

Is there any sort of converter box or something that will allow me to read and write the various canbus signals to then input into the Adaptronic? I don't really want to have to install a heap of extra sensors if I can just read and write the values to and from the canbus system.

[StuC]

i think Motec do a unit for this, I recall reading something about it

[TERRA Operative]

Hmm, close, but their stuff only works with their ECU. I need to interface with the stock canbus so I can get outputs and maybe inputs to the stock ECU and Gauges, Transmission, etc.

[wilbo666]

I don't know of anything, but that's not to say something doesn't exist!

A few things spring to mind such as you could look at using a little micro (such as atmel's atcan series) with a DAC to make the inputs to the adap...

Or does viper have something?

Cheers
Wilbo

[AndyTTR]

Correct me if I'm wrong, but from my understanding you'll need a 'directory' file in order to interpret the data stream? Manufacturers try to keep that info close to their chest...

What are you trying to do, install an Adaptronic to run the engine stand-alone? Or have you already installed the Adaptronic and want to broadcast info on the CAN for other modules in the car to read?

What signals are you hoping to read from the CAN? A lot of data is broadcast on the CAN, everything from transmission oil temperature to the position of the fan-speed switch in the climate control. You could get some useful data from the OBD port... surely someone (in china probably) makes a digital to analogue converter for that?

To run the Adaptronic you shouldn't need to make up a whole new loom or install sensors. All the existing sensors and signals will be wired to a control unit somewhere (probably the engine ECU itself) which then broadcasts them on the CAN. You should be able to tap into the analogue signals at that unit...

Sadly, the next generation of car enthusiasts will need to be computer programmers as well as mechanics.

[timbosaurus]

Like AndyTTR said... the sensors will be there, probably running to the standard ECU which I assume you are replacing with the adaptronic?

[beerhead]

Sounds like it might be worth piggy backing the ecu to keep the ecu thinking its running the show.

[gmonkey]

i have canbus in my astra... lets just say its the DEVIL.. it controls everything (aircon,lights,instrument cluster,airbags, everything!) your best bet is yes a piggy back ecu to not have any canbus issues with electronics..

[TERRA Operative]

I want to run the engine soley on the adaptronic as being a stroked engine (4l to 4.8l) the stock ecu is freaking out, but the canbus is spread through the car like a virus. The stock ecu does everything from the alternator charge rate, to the gauge cluster, to the airbags and also interfaces with the transmission and abs.

I need to retain the stock ecu and keep it happy so everything else works, so save for a complete rewire back to pre canbus from an earlier model, I either need to create a canbus adapter so I can read all the engine sensors without messing things up, or add an additional harness with all new sensors just for the adaptronic.

I'm beginning to think a rewire is the easiest thing. I have half the looms already, and it's not hard to find the rest.

[gmonkey]

Maybe do a precanbus ecu unit to control just the engine if it's possible? Or look around for someone who can tune canbus cars there's not many around, last I checked only one I could find was in qld (that's for the astra but) other than that maybe contact someone in the states to tune it for you by posting them your ecu

[AndyTTR]

The stock engine ECU wouldn't controls the airbags and ABS... what you're probably finding is that with the ECU unplugged the CAN is open circuit and hence not working, so none of the modules can communicate with each other. You could try terminating it with a 120k ohm resistor and seeing which systems still work. The engine ECU probably provides the signals for tacho, engine temperature etc. - which ever systems need these signals to run will throw error codes. Is it a combined engine / transmission ECU? Does the car have a factory security system?

Rewiring it won't help as you'll lose all the systems which operate on the CAN - instrument cluster, ABS, climate control... maybe even the radio if that runs through the Body Control Module (BCM) unless you swap those units for the non-CAN versions as well. Way too much time and effort - you'd be looking at rewiring and replacing every electronic module in the car!

IMO your best bet would be to find out if someone over in the USA is able to re-program the factory ECU and convince them to share their skills... It seems to be a pretty common thing with early 2000's cars over there, for example LS1/2/3 ECU re-flashing is fairly common. Those can be re-programmed to operate without the BCM and the BCM can be re-programmed to operate without the engine ECU.... might be something to look into? Jeeps are popular with the enthusiasts over there, I'm sure someone will know something about it...

[TERRA Operative]

I can easily get all the bits to replace all the canbus gear. The problem is that if I reprogram the system to enable me to remove the stock ecu, I'll have to replace the gauge cluster and alternator and all associated wiring anyway as they will no longer work.
Also, the transmission control module is tied into the ecu, so I'll have to replicate the lost sensors to correctly run that.

Or I can just swap it all over. I've done quite a bit of work on the cherokees, and so far, this is looking to be the easiest option.

I can't just send the stock ecu off to get reprogrammed as it cannot be correctly tuned without the rest of the package, and removeal means a rewire anyway.

[timbosaurus]

I think andy was inferring that you keep the standard ECU, but just get the maps tweaked... hence keeping all the standard CAN communication and electronics, and just avoid running the adaptronic.

I don't know the slightest thing about jeeps, but just to re-iterate what is said above...

You have 1 (or more) CAN bus's throughout the car. Usually you have a high speed version linking the engine control module, the trans control module, the brake control module, and a control module for body functions (like windows/locking/mirrors/seats/etc). You may also have heating/aircon module, instrument panel control module (cluster) and many others.... or those non-essentials could be OFF the CAN bus and hardwired to something like the body control module, or on a secondary bus

Once you work out what modules are on the CAN bus, you'd need to understand the communication details. CAN is standard, but what specific data is in what bytes, in which frame ID, how it is scaled, and at what frequency it is sent is different from model to model (not even manufacturer specific). There may be hundreds of frame ID's, and can be thousands of signals (packets of data, like RPM or airflow or speed etc) throughout. Without a database of this information for you car.... you're pretty much screwed. You might be able to analyse the data and interpret a few bits and pieces, but that's about it.

All modules on the CAN bus can send and receive, so if you pull out the engine control module (and either short the CAN pins if the module is pass-thru, or replace with a 120ohm resistor if it is a terminating module) all of the other modules will still communicate, but the engine data will not be available. Unfortunately CAN is pretty smart, and in this situation the other modules will notice the missing module, and may react accordingly, falling into a failsafe mode.

What i'm saying is that replacing the Engine control module with a home-made CAN tranceiver would take a LOT of reverse engineering (unless the data is on the net already?)... a level of work beyond most people. It is highly likely that even if you can replicate the basic (rpm, coolant temp) signals, that other modules would still not behave right.

I think remapping the factory ECU (if possible) is the way to go.... otherwise you need to hope the factory ECU can run in harmony with a piggyback (or if you'r lucky a stand alone like your adaptronic), or replace the whole shebang with an adaptronic and non-CAN based instrumentation.

[turbo ke20]

throw the adaptronic in the bin and get a haltech platinum series.

[timbosaurus]

hmmm... i like the new haltech's too, but I don't think it's going to help him one little bit in this instance