I recently picked up a Supercharged Range Rover. It uses the 4.2L supercharged Jaguar engine, I imagine very similar/identical to what you guys have

I'd like to dig into the software behind it. I have a lot of experience with Bosch systems, but next to none with the Denso engine management employed here. I have done enough searching to know that one of the common gripes enthusiasts have is the lack of comprehensive tuning options, so I'm not expecting state secrets here, but rather I'm interested in whether power output was increased/decreased when using a similar powertrain across the model line. A de-tuned version if you will. That'd get me moving in the right direction, seeing how the manufacturer handles such things.

I've managed to come up with the necessary calibrator files/definitions for this, and I have the ability to read/write the factory ecu. Problem is, I have no point of reference here. I've as of yet been unable to come up with any sort of documentation on the framework or strategy that's being utilized.

I'm not sure what the etiquette is here, or if this sort of discussion is frowned upon. If it is, I apologize in advance. I will happily share anything I come up with if there are any like minded individuals amongst you.

Thanks in advance, DD.

 

Forgot one thing:

Datalogging. Is there a preferred diagnostic software/datalogger that's used here?

 

Others with more knowledge will chime in but my understanding is that the factory codes for programming the ECU on the 4.2 have not been broken. If you manage to get into the 4.2 for tuning then you will be a hero on this forum. As all of us have been looking for tuning options on the 4.2 for a long time.

 

I have read and written my ecu already, and started identifying maps in my particular software version. As it's not Jaguar the calibration is a bit different than the definitions I've come across, but it's similar enough that it won't be a problem to identify the required maps.



It's not a matter of IF, but rather when

 

The most capable diagnostic software and datalogger is the real JLR WDS/IDS/SDD.

You can find knock off cables and the software on ebay and other sites. There is a long thread about these.
https://www.jaguarforums.com/forum/g...an-tool-66558/

I have one, works pretty well. It also has all of the calibration files for your hacking pleasure.

 

I have the Ford/Rotunda IDS, and I have a mongoose cable. Guess I'll do some research into it.

Appreciate the reply.

 

If you've got a Mongoose then the JLR software should be easy enough to find. Most of the ones on eBay etc are cracked to disable the phone home functionality. I've got version 134.

If you do get to where you can modify the Denso ECU, I personally would be VERY interested in adjusting my own 4.2 XKR.

 

I can modify it now. Knowing what to change is another story altogether without documentation.

Do you have your specific ecu file that you could post/send me? I'd like to see a production version.

 

PM sent

 

How are you dealing with the checksums?

 

Although if anyone want's to work on an opensource c'sum corrector, I'll assist.

 

Do you know the algorithms and offsets?

 

I don't, and TBH, I haven't given it much thought considering I have the plugin, but like I said, I would be willing to contribute what I can. Considering I can make changes, checksum the files, and then view the corrections, we have a jumping off point.

 

Does anyone have a pinout for these ecus? Showing power/ground/can/k-line (if applicable)?

 

I've moved this thread out of the XK8/XKR section to the Engines section.

Avos here on the forum has played with the Range Rover version of the AJ33S so he might know a thing or two.

Also have a look in this thread, Moscowleaper is working on reverse engineering the files for the X350 XJR (same engine) https://www.jaguarforums.com/forum/x...ng-sdd-130103/

 

Thanks! It was best guess where to post it anyway

 

There are several places you can piece this together.

The wiring diagrams would show you the pinouts at the DLC and at the ECU proper.

Additional clues can be had by looking at the documentation from the Drew Technologies
site for the JLR specific version of the Mongoose dongle. Note the pin and follow it back
from the DLC to ECU on the Jaguar wiring diagram. This will get you some of the
undocumented pin definitions. Some of the pins are well defined in the OBD-II standards
and are immutable between vehicles. It is the "optional" pins that you will be looking
at.

There is also the Rover documentation since the pinouts will be identical given that
Siemens keeps the same pinouts across the board for a single model of ECU.

 

No worries

There are certainly more tuners who claim to have gotten power gains from the Range Rovers 4.2 than for the Jaguar's of the period. Which makes sense since the Range Rovers are more plentiful and there seems to be a bigger aftermarket support for them.

Avos has put a twinscrew supercharger kit on a 4.2 Range Rover Sport, and it needed some tuning to get it to work properly, so i'd really suggest you get in touch with him.

This guy https://www.jaguarforums.com/forum/p...59/#post243827

What we do know is that there are limiters built into the ECU's which will throttle back the engine if "too much" air is drawn in, this has an effect of limiting the torque output. If you want to get the most out of the 4.2 then the limiters have to go.

This is what MoscowLeaper is working on, but if i'm not mistaken Avos has a guy who was able to remove the limiters from the Range Rover ECU when the twinscrew was installed.

The ECU's on the S/C Range Rovers are totally different to the earlier 4.0 V8 XKR & XJR (which don't have limiters), but seem to be similar to last models that had the 4.2 i.e. the XF SV8 and the X150 XKR. The S-Type R and X350 XJR seem to have a different one again, but they too have limiters programmed in.

Here's an example of what I mean;



If you see a dip like that at "peak torque" on the power curve, then that's the limiter kicking in.

You can mess about with fuelling & ignition timing all you want, until you defeat that limiter you won't be getting any more power...

Off course the power will drop off anyway at the top end because of the design of the M112 supercharger, but the ECU is definitely pulling back as well.

 

There are quite a few torque limiters defined in the pre-production files I have, but as would be expected in calibration files, they are disabled. Still, it won't be difficult to find them in a similar Jaguar file.

Does anyone know how the limitation is executed? Ignition angle? Throttle plate angle? Bypass valve?

 

Throttle plate angle it would seem, but i'm told also fuel + spark retard in some cases.

Definitely not bypass valve (long story behind that one LOL)