Another GM Fail
Got called to do a computer update for a garage. This is a shop that I have done work for in the past and these guys are pretty sharp. Their customer wanted this done as he had seen a TSB somewhere. At about 75 % of the writing process it failed. I shut it all down, checked all my connections, and restarted the process. It failed again. I got an e4423 and e4492 programming code. I am unsure of what the e4492 code means. It did say Cyber Security Access Failure. However, now the ECU is a no comm and of course a no start. I have comm with all the other modules. I have had programming failures before, but never one that rendered the ECU to a no comm. If anyone has any thoughts on this I would love to hear them. My call to GM went nowhere. Any help is truly appreciated.
Wow thats a pretty good TSB. Wonder why the help desk didn't know that when he was on the phone.
Phillip, I never got to the help desk. I am still waiting for them to call back.
How concrete is the ‘no communication’ ? There is cases where the modules appear to be a no communication and yet will accept a programming event. New module installations. Just passing that on in the event you may be able to try again even tho it looks to be a no comm.
Maynard, I have tried 2 different scan tools and I also tried the programming event. No comm with anything.
Sorry, I don’t have access to my computer at the moment (and on terrible WiFi so I can’t look). I know Cadillac had a couple Global B models in 2019 and I know it’s been a struggle to program those platforms with anything other than an MDI2. Again, not saying that’s what it is, just don’t have access to login and look but wanted to throw out there to possibly help.
Their may be some additional help here: diag.net/msg/m1vpuww9r0… gmrepairinsights.com/programming-er… productforum.autorepairdata.com/forum/showthre… static.nhtsa.gov/odi/tsbs/2016….pdf gearsmagazine.com/magazine/oh-no…
Randall, Thank you for all the links. I have read most of these and still have my problem. I see a lot of information for e4491, but I have found nothing for e4492.
You may have seen it, but this was the only reference I found for a E… savana, information 2 months old): "Good day all this van came in as a no crank no start. We diagnosed it to have a bad theft deterrent module not on the low speed bus. Replaced the module and lock cylinder with new key. Programed module and key but ecm doesn't receive the ok from the bcm during programing we get an…
I'd suggest that you purchase an MDI2. Well worth the investment. Also, GM will not provide support to someone who is using a non-validated interface. Autel Ultra and IM608 are not supported officially by GM.
Any chance the module already has the correct calibration . I saw that code yesterday just a lost communication code .
David, Not much out there on the e4492 other than this (iATN is still good for something) I'd be looking real close for something aftermarket connected to the bus. members.iatn.net/techmail/view…
Jeff, Thanks for the reply. I just got off of the phone with GM and after an hour or so, they said that they have no idea of what could have gone wrong and no idea of what to try next. They were very pleasant though. They told me that I need to reprogram the unit again and I told them it would not communicate. They said to replace it. I have looked all over the car for anything aftermarket…
I would definitely try a different vci, we had a 2002 trailblazer the customer put the wrong pcm in and the gas gauge worked backwards. After three hours and isolating the bus the bosch vci worked after the mdi 2 and cardaq failed.
Sounds simple but it's bailed me out of many a failed write, hard reset, unplug module/wait/replug.
William, Thank you for your reply. Reset was one of the first things I tried. Nice to know that someone else feels the same way I do.