Hello , I wanted some opinions on thoughts on code p26c8 on my 2016 c7 - I thought it was due to an AWE exhaust install the shop did , after some time them trouble shooting they say it’s not . Now they want 200 plus to diagnose it further?
ket me say very nice performance shop but not specialized with Chevy more euro - but install was great but now the trouble light and I’m not sure if I should let them proceed or will I just be wasting money -
the chassis module is the code , can it be the module itself ?
should I bring it to Chevy ?
or another shop performance more familiar with Chevy ?

what else can it be ? Any thoughts ??
I appreciate it -
thank you

 

Did they install the entire rear pipe section or just the x-pipe?

 

This is what sets the DTC and also diagnostic aids…can be a communication or “U” code or a “P” or Powertrain DTC…dealerships and general repair shops only replace parts…a diagnostic shop is where you should be bringing it…they can diagnose any car…you only bring your car to a dealership for oil and brake changes…that’s it !!…also “Performance” shops are clueless with diagnostics…they just install performance parts.

 

they installed a cat back exhaust , I have the 4 valve system with the AWE valve brackets installed

 

Hey , so are you saying only certain Scan tools can clear that type of code ? Wouldn’t that be the dealer ?
I’m not sure what you mean by a diagnostic shop ? I’ll do that , that would be great but not sure on my area who that is -

the code is odd , I was wondering do you think it could bring the module itself ? Just need to be replace ? Or could it be spark plugs did it misfires or something just throw a weird code as some cars-
i just feel like the shop didn’t really do a good job checking the valves , my fault for bringing it there but not sure where to bring it next ??
crazy

 

Sounds like they didn't plug something back in.

 

After further research the Chassis Control Module controls the AFM valves.

What did they do with the wires to the valves? If they just cut them, no bueno.

EDIT: If the AFM valves are not being plugged in that would **** off the car royally. https://www.corvetteforum.com/forums...dule-code.html

 

they hooked the wires up to the valves and awe has valve brackets that connect to them -
so they are plugged in ?

 

The only way to know the exact problem then would be to get the DTCs out of the Chassis Control Module. I looked at the service manual and it doesn't seem like an overly complicated module electrically. But it's unhappy about something and that sets the code in the ECM.

Typically this is done when a module doesn't want to be emissions compliant directly (that requires supporting a host of diagnostic services) so what it does is it tells an emissions compliant module like the ECM that it has a fault and the ECM then sets the emission fault.

 

Your Chassis Control Module will have some P12XX code in it, where XX is E3-FF in hex, and that code will tell you what is wrong with the AFM valves.

FYI Hex counting is after 9 comes A-F then 0. So E9 then EA after EF is F0.

EDIT: see the picture in this thread https://www.corvetteforum.com/forums...hp-tuners.html and this one https://www.corvetteforum.com/forums...r-install.html

 

hi ! Thank you very much for the time and help !
Do you think I should just go to Chevy then and have them read the codes ? Maybe it’s just an emissions issues- I don’t think the place that did my exhaust can read past the p26c8 code ?

they never mentioned any further codes -

thank you

 

You will need some shop (like a dealer) who can read codes from any module. The dealer though will likely not tell you the codes. They will read them and attempt to fix the problem though, which with an aftermarket exhaust they might not be able to.

Or you can buy a code reader yourself, but it needs to be manufacturer specific not just a generic OBD II reader. I have a Foxwell scanner for example.

 

Don’t know what you mean by “manufacturer specific” ??….any factory level aftermarket scan tool will work for any platform not just GM…Autel, Launch, Bosch, Topdon and a few others…the dealer will and should inform you of the DTC before diagnosing the car.

 

Many 3rd party tools, and some OEM specific tools will not work with other OEMs unless you have them "unlocked".

I know you are thinking of the BOSCH VCI tool which you connect to a laptop, which with any OEM software will work (it's also like $2000). I'm talking about some fully self contained tools which have various OEM Libraries. Foxwell for example requires you to spend $50 to open additional OEMs on their tools (you only get one OEM when you buy the tool which the basic scanner costs only $150).

 

Here is the tool I have -> https://www.foxwelltech.us/product-detail-524.html

Which was way cheaper than the "generic" Bosch VCI ->https://www.boschdiagnostics.com/pro...h-ii-j2534-vci

Versus the Ford VCM -> https://rotunda.service-solutions.co...?SKU=164-R9865

Versus GM MDI ->

 

Stellantis, Nissan, and Mercedes Benz each require a subscription to Auto Auth to bypass these manufacturers “secure gateway modules” to access their data…even your Foxwell will not have most of the special functions and data PIDS as my factory level aftermarket bidirectional scan tools will have and mine by Snap On, Autel and Bosch are well over 2K…I run GDS2 on a separate laptop…basically the more these scan tools cost are the more they can do.

 

I'm very well aware. I work for an OEM (Ford) in Software, I have all the Ford tools on my laptop (like FDRS but also plenty of engineering tools). Before I worked for suppliers to GM and to Chrysler. GM doesn't have very many engineering in-house tools, Chrysler did (not sure if they still use CDA internally). But everyone including suppliers also use Vector tools like CANalyzer and CANape.

But for most things on the service side, the Foxwell works. It can run most routines (Service 0x31) but if there are any "off-board" routines it usually doesn't have them (some which are in OBD tools are OBD routines it can emulate). It also cannot flash modules, its strictly a diagnostic tool. My dad has the one for his BMW and we use it for example to run the routine to disable the electronic park brake so you can swap the rear pads.

FYI, PID is sort of an outdated term, a lot of tools still use it but the term PID actually only refers to "OBD" (aka emission) data identifiers (known as DIDs). Those are all read via Service 0x22 and written via Service 0x2E (all those are UDS services). I know the ISO 14229 UDS Spec pretty well. I wrote end of line testing scripts at an old job but being a resident engineer, then a design and release engineer at the suppliers I was always diagnosing issues so being familiar with various tools and diagnostics became a necessity. Then I wrote specs myself, I actually defined all the steering diagnostic services at one point at Ford as core steering functional spec owner.

 

Thank you all for the input ,
I have to say AWE tech support has not been great -
I love the exhaust sound - but not really helpful -
I asked also if they can recommend a shop that may work closely with there product in CT for a better understanding and maybe more familiar with the exhaust .
no response

but thank you I’ll bring the the car to the dealer , and see what the codes are in the DTC

 

DTC is what codes are called. There are no codes in a DTC. The CCM is the module that has a problem and the ECM is showing the above code, which tells you the ECM is fine, but there is a problem in the CCM. The simplest thing is to check the wiring from the muffler outlets back to the CCM and see if it is not cut, disconnected, or otherwise disrupted. I suspect the shop didn't complete the installation properly.

Bill

 

thank you bill ,
im hoping it’s something simple as the wiring , but they claim to say it’s not ? So I didn’t get a warm fuzzy feeling about how well they looked -
so I’m going to take it the dealer and see what they can verify what the code is , and hoping nothing else major / car runs great but just that code -
appreciate the input !