Hi out there,It's been a while,but Im setting my 68 year old but on this chair and crying out for some good knowledgeable help for my much loved 04 Z06 which has increasingly developed so many problems,that I have respectfully wore myself out seeking and paying for various professionals only to have it go from bad to worse with no end in sight.Im sitting at my desk ,its 4 in the morning and a huge day tomorrow,but I don't care, for this tragedy has enveloped me.I could not tell you all of it at once,its too much to digest.OK, K.I.S.Stupid.Upon my car up and dying on me without warning,I was getting all kinds of codes some having to do with class 2 data link communication malfunction,also ck the traction assist,active handling,and ebcm,those three popped up.I did some research,and had the pcm refurbished and flashed and the ebcm module sent out and rebuilt/relearned.Upon reinstalling these,the car would not start.Oh,the PCM had a instructional paper in the box,stating the crankshaft re-learn procedure had to be performed.I take the car to my local chevy dealer,who has the special class 2 serial data scan tool.Technician states he cant perform crank variation re-learn unless the engine is running.servive man says they can diagnose the problem.Three Hundred dollars later he says it needs a new fuse block underhood.They Quote me eleven hundred some odd dollars to replace it. I leave suspiciously,go home and begin to diagnose myself.I go thru the same procedure as he (I have the same double book service manual) And find the fuse block passes testing, and it ends up to be my fuel pump.After a difficult replacement I performed,the car starts up and I'm driving.After months more work on upgrades I'm doing,the computer is clear of all codes except the po315,crank re-learn.A friend who has a HP tuner says he can take the ck engine light off,so I can go get it smogged which is a year out by now,since I barely drove it.Also we can use the licence I purchased when I install my procharger.He removes ck en light, the next day while i'm driving to smog shop the light comes on again,this is where it starts to get ugly.I decide to drive strait to the chevy dealer and pick a bone with them about my $300 wrong diagnosis. we work it out so I can bring it in the next day and they'll do crank learn no charge.The next day as I'm driving to dealer light goes out but I continue so no future problems.They also say i have a fac recall on steering lock/engine start.I get a call they say the tech broke the puller trying to pull wheel new wheel not covered, if broken $1000 I pay.No thanks,leave it alone,I say.Pick up car,go to smog guy, he says wont pass cause some "U" codes showing.I take it to his neighbor who does diagnostic help.he puts his scanner on it says no codes but he shows me no communication to cats and his says no crank re-learn performed yet.I tell mechanic to re-learn crank, he tells me to cruise at 60 to 65 for several miles and the cats will start to read pcm.go back to car my diagnostic on board still shows many codes and to make things worse car kept popping up ck traction control and car is feeling a funny pull as the service traction control soon shows.Worse still I now have a air bag light on at all times his scanner showed 'wire stretched' as reason for air bag notice mechanic says dealer screwed up air bag trying to remove wheel.So now I have my air bag problem I'll take up with dealer,also traction service popping up consistantly, and car pulling at rear when displayed and according to my dash diagnosis,all those codes show but dont show on other mechanics scanner.I doubt if anyone has an answer for this mess,but its got me frazzled.New computer? Helllp!

 

Yea it,s me,I figured nobody would touch this.I was right.Too much information? Sorry. Well,Im going to put my little PMX Bluetooth scanner on it and see what I get.What a mess! Thanks anyway

 

Cliffs?

 

Ist you cannot perform a crank relearn If there are any P code DTC's Thats why the dealer could not perform the relearn
Often with modded engines such as cams or boosted you will get many codes
What i do is to set ALL the DTC's to read NOT REPORTED and then also NO MILL Flash this into your ECM without starting the engine
Now you can start the engine and do the crank relearn as no P codes will appear and prevent it --Also the coolant temp must be above 185* for the relearn to work
As far as the traction control issues go most often it is a fouled wheel speed sensor located at each wheel Inspect all 4 pigtails to assure there are no frayed wires and then also clean all the pigtails with brake clean and plug them in again
Have you changed any of the tire sizes to NON stock ??? Have you changed the rear end diff ratio ?
Without proper tuning these changes will cause TC and ABS issues
As far as the column lock fuctions and air bag issues That is just bad luck !!! There is a fix for the column lock issue but not for the airbag fault I would contest the dealer for messing the airbag up PLUS the airbag system is a safety issue and they often will fix it rather than have someone die in a collsion and be sued---

 

Boy do I appreciate your input.The technician that helped me said I had no codes but his scanner showed the crank re learn had not been completed, and there was no communication with the cats.Well I put some time and perserverance into it today,and finally got all the p codes(about 15 or so) erased.Ck engine light is off.a good friend told me the same on the EBCM and traction problem.So I can deal with that now.Going to dealer in morning and insist they fix what they ruined.Two codes left, B0022HC Iooked up and it's the left front driver frontal deployment loop,sounds to me like the wire they pulled loose on the air bag.This leaves me with code A-6 SCM-no communication,has to be the not communicating with cat problem.I drove over 100 mi. last nite in hopes of it working but only noticed the engine doesn't feel rite.Looked long and hard for the code but couldn't find it.You've been so helpful, do you have any advice for this final problem?I sure would appreciate your input.I'll be checking in periodically.Thanks very much,I do remember you from years back.

 

Did you try to delete ALL the DTC codes? to read not reported and no mill ?? This would allow you to do the crank realearn---As far as the communication codes go Those will not affect passing smog--Only the P codes will----Communication codes can be tricky Worst case is a bad BCM controller 2nd would be a bad ground somewhere--These LS engines are very ground sensitive--
Is your car an auto trans or a manual trans ?
have you tried to dis able the TQ management how i described ?

What tuning software are you or your tuner using? I use EFILIVE If that's what is being used send me a copy of your tune file Send me a message here and I will give you my Email address--
Finally what exactly are your issues now ? as far as driving the car Is it driving normal ? and you just have those pesky U codes ? or is something else going on
PS If you would like to discuss on the phone send me a message with your phone #

 

tblu92,I looked forward to hearing from you and you came thru,thanks.Quite a bit of headway has been made,and I'll try to keep the discussions on each problem separate to avoid confusion.I was able to, after several tries,delete several codes in the b's,a few in the c's,a couple IPC's'and quite Importantly, the 2 or 3 u's(data link communications).Now interestingly enough, my smog man said the opposite of you.He said he cant pass smog with any 'u' codes present.Well,they are gone also, but we have a different can of worms left which Ill explain momentarily.The crank re-learn p-315 is also gone.The last mechanics scanner by the smog guy showed crank re-learn had not been performed, and there was no communication of PCM with the catalytic converters,and the SIR would not deploy due to a wire open circuit.Now,I brought this to the attention of the service manager at chevy dealer,and he made a good point.I recently installed a *** version of a corbeau seat on the driver side.The SIR light came on the day after I brought the car back from the dealer,leading me to think it was results of trying to pull wheel.I would have had to adapt the plug to fit seat belt plug, and left it open for now.I'm going to reinstall original seat before I point the finger that will verify problem.Oh the mechanic performed crank re-learn again and code is gone.This leaves the most perplexing problem,but the only one not completed.It's a impossible for me to get any information on says A-6 SCM- no communication.This is the one the mechanic told me to drive at 60-65 for as long as i can. Well Itook it to Modesto and back to antioch nit before last.I then plugged in my Blutooth scanner,Put it on live display of oxy's,and I've never seen such a mess.The upstreams were going crazy,not a hint of unison, they looked like a 3 year olds scribblings.The downstreams looked flatline strait line.It also said secondary air off.I'm going to climb around under there and see if I can find a physical problem cause it's a mess down there.Haaalpp! P.S. I'll look for ground problems too.Talk Soon.

 

You Can call me,Dale,at(925)642-8430, If you'd like

 

The UPSTREAM O2's are supposed to oscillate between 200-800 mv...can you take a pic of the upstrams at 3000 RPM ??...the DOWNSTREAMS are supposed to be steady somewhere around 700 mv or so...what is NO COMM of PCM with CATS ??...never heard of that one. And are you saying you can't communicate with your SCM using a scan tool ??...if you can't communicate with it you'll have to check power and grounds at the module !!

 

An answer to your question about never heard of no communication with cats.Well Iv'e never had this problem either.The gentleman that was referred by my smog guy,a couple doors down put his scanner on my vette.what he got was 1) no crank re-learn had been performed 2) a' b' code had shown in reference to the driver air bag not in service and 3)most importantly, his scanner said there was no communication with the catalytic converters! So I plugged in my little scanner,put it on live sensor display and went to oxygen sensors to see if there working correctly, and observed a mess. Upstreams all over the place. and downstreams looking flatline.Also secondary air pump off.This one I tried several times to delete,but to no avail.Code mentioned said A-6 SCM,of which I could'nt find .Any input would be appreciated

 

Just realized the A-6 SCM related to the driver seat being disconnected because I had installed a Recaro off brand seat and could'nt re plug the wire connecter under the seat.Not realizing the impact it would have.Im going to replace stock seat immediatly.But I still dont show communication with the cats as the tuners scanner had said.Going to start climbing around under there and see if I can find something disconnected. Bye for now,I'll try to get picture if needed.

 

Well if a crank relearn needs to be done you will need either a bi directional scan tool or a GM Tech 2. When we speak of NO COMMS we talking about the 12 computer modules in the C5... HVAC, Radio, BCM, PCM etc... your cats are not a computer module and I don’t know what your mechanic might have been referring to ??...Now do you know what a good and bad O2 sensor waveform looks like ??... if not it may be difficult for you to diagnose a bad one...the other code you mentioned (A6-SCM) is your seat control module...one of those 12...you said something about the seats that you replaced...the SCM is under the driver seat so you may have to look at the connector and/or wiring !!

 

Here In calif where we have the strictest smog laws in th nation They only will look at P codes and readiness monitors--
These are the only codes that would affect emissions as do the rediness monitors
U codes and B codes are not looked at as they have no emssions input----- Don't know which state you live in but I cannot believe a smog shop would fail a smog with only a B or U code
This would mean they could fail your car emssion whise for an air bag fault or an ABS fault or an A/C fault-etc nothing to do with the engine or emssions

 

Hi There tblu92, and C5 Diag, I appreciate both your inputs.Let me back up a bit to start.What I have is a C-5,2004,Zo6,with 38,000 mi, lots of suspension upgrades,and hopefully more to come,w/brakes,4 corner weight,bigger wheels,and wheel alignment,to come in the future.As for engine;stock air intake back in.Replacing Vara Ram,and other than cat back mufflers,all stock for now.When tblu92 mentioned setting all DTC's,as not reported,then the no mill flash into ECM,then start engine to above 185%to perform crank re-learn,he may have thought I had a powerful scanner,where I only have a Diablo Sport Predator,and a torque OBDII Bluetooth.Also,I do live in Calif.East Bay Area(Antioch).As for the column lock recall issue,I did replace the stock drivers seat,plugging in connector under seat.This did not erase the red airbag sign pop up,nor did it remove the B0022HC code describing the airbag issue.The A-6 SCM-no communication, related to this.To make it worse,there is a sound of a piece of plastic rattling inside my steering wheel that started the day after I picked up car.It's scheduled to go into shop this tues.morning.That's when the Tech who worked on the car will be in.To answer your question about the cats not communicating, I don't believe there was a code for this.The mechanics scanner just spelled this out.I'm not a pro, but I can tell you,I've seen enough up and down stream Oxy-sensors live,to know when somethings very wrong.I know the upstreams will have a correctional type of not looking perfect, and the down streams will look more consistent since the computer has corrected this with a rich or lean air correction into the cats.Something like that.I tried in vain to get a picture of my live streaming but could not get my ObdII to pull up my vette.I'll try again,and if successful,will include pics.As I said when I did pull it up recently,the upstreams,looked like nothing I've ever seen(a mess),and the downstreams were flatlined--------------------------like that.Thanks Guys,I'm going to look for a physical problem.I'll get back when I find something.