Supposedly they replaced the cat back system for you. That means if you had a Stingray or Z51 you had 4 valve actuators (2 in the inlet of the exhaust and 2 in the outlet of the muffler that had to be transferred over to the new exhaust valves and have the connectors for each reconnected. All the CCM does is control those 4 valves. If you have a wide-body car then there are only 2 valves and 2 valve actuators located in the outlet of the mufflers.

The CCM schematic below shows the AFM valves and actuators on the left side and the muffler outlet valves and actuators on the right side:



The actuators are all the same part number and can be swapped around. If they moved them between positions the CCM might not recognize the actuators if they are located in a new position. The FSM clearly states they need to be relearned if replaced or I suspect moved from one position to another since the CCM isn't smart enough to recognize an actuator swapped to a different position.

Here are the applicable diagnostic pages from the FSM:

















I really can't see this as being more than getting the car in the air and performing a visual inspection of the wiring and if that doesn't show anything disconnecting the 4 connectors under the car and performing a continuity check between the pins on those connectors and the corresponding pins on the connectors attached to the CCM which is mounted in the rear electrical center to the passenger side of the fuse panel.

One question I have remaining: Did they do any welding when installing the exhaust on the car? If they didn't take proper precautions, welding on a car can generate stray voltages that can damage a car's electronics.

Bill

 

Bill and I are basically saying the same thing. This is a wiring or valve issue. More so with AFM than NPP. The CCM can't set the emission code for bad NPP valves (it sets a DTC but that DTC doesn't cause the ECM to set a DTC). Faulty NPP valves are not an emission issue, faulty AFM ones are.

 

hi Bill ! Thank you very much for the detailed explaining, I’m not a expert by any means -
but this helps me understand ,
because they said - they are plugged in and opening and closing as they should - with the AWE valve brackets -
there are 4 of them -
but I wonder if they did switch them around ? By mistake ?
that could be for sure -

it is a ccm code the p25c8-
il not sure of the dealer will re plug or try the valves in the correct position ? But I’ll mention it to them first sure -

thank you vey much -

 

P26C8 is the DTC/code in the ECM. The CCM code will be the one in the list shown in Bills screen shot, or listed in my earlier post.

Sorry, I can't think of any other way to explain it, to me since this is part of my job is all very easy to understand and clearly we aren't communicating something right. The ECM and CCM are different "computers" in the car. Some test tools can only talk to specific "computers" if you don't have the right tool you can't talk to the CCM. The ECM, and a few other modules (like ABS/EBCM) are "OBD" or "Emission" modules which means they follow a public regulated standard that is published and nearly every tool can talk to. Even $100 ones from auto parts stores. Other "computers" in the car require you to have a manufacture specific tool (or one that is cloned to be like a manufacturer specific tool).