New ECU now no cruise control

Hi all,

I had my ECU replaced under the fan relay recall. A day after the replacement I find I no longer have cruise control (with no CELs). After a little research it seems there are specific ROM versions for the '05 that are required for the cruise to function properly?

Would someone kindly provide some details to what the issue is? I will be talking to the dealer tomorrow and I would like to be armed with as much info as possible.

Thanks,

Rob

After further research it seems there was a neutral switch difference between '05 and later LGTs. The image on the new ECU is A2WF200N which I think is stock for the '06 ECU that is used as replacement (part# 82501AG120). The original image on the stock ECU was A2WC510N.

Is it as simple as the dealer flashing an '05 image onto the new '06 ECU, or would their be a hardware incompatibility? Since I am not allowed to monkey with the family hauler, I haven't paid too much attention to reflashing details.

Thanks,

Rob

After further research it seems there was a neutral switch difference between '05 and later LGTs. The image on the new ECU is A2WF200N which I think is stock for the '06 ECU that is used as replacement (part# 82501AG120). The original image on the stock ECU was A2WC510N.

 

Is it as simple as the dealer flashing an '05 image onto the new '06 ECU, or would their be a hardware incompatibility? Since I am not allowed to monkey with the family hauler, I haven't paid too much attention to reflashing details.

 

Thanks,

Rob

The 510N ROM is what my car uses. So yeah, you'll want the same ECU version. If the dealer messed it up, they should fix it. Otherwise, you can download the correct ROM and flash it over yourself.

It is surprising that they put an 06 ECU in your car, I suspect that they just screwed up. Was the original ECU damaged by the fan relay issue, or is that how they "fixed" it?

I went in for that recall fix with a working ECU, and I still had an 05 ECU afterward.

I've been down this road. For fun in an aggravating kind of way, shift into neutral while cruising down the road. Now you can set cruise control. Rpms will keep wandering up up and away and when you put it back in gear it cancels cruise control. Useless for sure. I once had an '06 image on my '05 also.

Don't let the dealer re-wire the neutral switch. Yes, it would probably fix it but what a stupid terrible thing to do. You need the correct image for the rom. The rom should be specific for your car.. probably the 510N.

FWIW, my 05 came A2WC510N, but is running A2WC522N now. 522N has bigger tables for per-cylinder timing compensation, but that was the only difference I saw. I'm not aware of any noticeable differences between them. So anyway, that one works as well.

There are also 511 and 521 versions out there, probably also compatible.

FWIW, my 05 came A2WC510N, but is running A2WC522N now. 522N has bigger tables for per-cylinder timing compensation, but that was the only difference I saw. I'm not aware of any noticeable differences between them. So anyway, that one works as well.

 

There are also 511 and 521 versions out there, probably also compatible.

Good point. I think the 522N was an update to the 510N.

Good point. I think the 522N was an update to the 510N.

Interesting. Can I "upgrade" from a 510N to a 522N ROM?

Interesting. Can I "upgrade" from a 510N to a 522N ROM?

I wouldn't since I don't consider my statement 100% guaranteed accurate. "I think".. Plus, I doubt there is really any meaningful upgrade.

Interesting. Can I "upgrade" from a 510N to a 522N ROM?

You can. I did, just out of curiosity...

I didn't notice any difference at all, though. In looking at the tables in the ROM, the only differences are in the per-cylinder timing and fueling tables - it's really minor stuff. If there's a measurable difference between them, I never found it.

Hmm...maybe ill copy my tune over to that version and see how it does for the heck of it.

Let us know what you think.

NSFW, in the stock tune on the 522 rom is there a cylinder that runs less timing?

You can. I did, just out of curiosity...

 

I didn't notice any difference at all, though. In looking at the tables in the ROM, the only differences are in the per-cylinder timing and fueling tables - it's really minor stuff. If there's a measurable difference between them, I never found it.

Did ECUflash let you write a different ROM without getting mad?

Did ECUflash let you write a different ROM without getting mad?

It took longer than usual, but it didn't complain.

NSFW, in the stock tune on the 522 rom is there a cylinder that runs less timing?

See for yourself... 510N A, B, C, D across the top, and 522N tables stacked below.

http://i193.photobucket.com/albums/z151/Legacy_NSFW/Tuning/PerCylinderTiming.png

I'm going through right now and copying over my old tables. I'll edit this post as I find things. So far the 522N has:

1. Wastegate Ramping Fix (510N doesn't have this)

2. Per cylinder tables are bigger (as mentioned above)

3. OL Fueling table is different, but mine was modified by my tuner anyway. Not sure which one to use here.

Edit- I successfully "upgraded" my ROM without incident.

Following up on an old thread; there is a difference between '05 and '06 ECUs. The dealer mistakenly installed an '06 ECU and that was the root of the problem. The ECUs have inverted logic for the neutral switch. This was confirmed by being able to set the cruise with the clutch IN and having it switch off with the clutch out on the '06 ECU.

-Rob

Well to be fair, it has been fixed for a while, but I finally remembered to update the thread.

No, it wasn't surprising at all. After my research, I was fairly confident when I first posted . It took a lot longer than it should have to convince the dealer they screwed up. Of course I am just another dumb customer, what do I know. At least that was their feeling until they double checked the work order and sheepishly admitted to ordering the wrong ECU. Morons...

The interesting thing was that they wouldn't reflash it, but had to reorder another ECU.

-Rob

That would be my guess as well.

-Rob