The pictures don't really help but can lead you in a certain diagnostic direction...does the car start now and can you connect your Tech 2 and communicate with any modules especially the BCM,TCM, and IPC ??...I'm not going to get into the whole CAN bus theory thing and how to diagnose it especially since it may be intermittent and this is all new to you...like I mentioned modules exposed to the elements see these issues more frequently so what you CAN do is access the TCM and remove the connector and get some electronics cleaner and inspect the connector and then give it a good shot of the spray...if you want do the same with the BCM...I just went through a 4 hour class recently on CAN bus diagnostics and it's NOT easy...but I graduated...LOL !!... !!...involves using a labscope, voltmeter, ohm meter, and sometimes ohming out each CAN wire from module to module, using jumper wires across different modules and some other methods...if there are any good mechanics that are good in electrical diagnostics in your area I would seek them out...the Corvette communication system is not special and is similar to other cars...just having the knowledge to diagnose it is.

 

Yes I can start my car.......Must the engine be running when using tech2?

Yes I can drive my car also some miles to it happens again, then Engine reduce power and engine Shut off.
Negative pol off from battery then wait 5 minutes. Then start and away some mil and so on all the time.

 

Unfortunately the Tech 2 will not diagnose this for you most likely…car can be running or just put the ignition in the “run” position…hold the bottom of the start button down for 5 seconds or so until the green start light comes on…with the Tech 2 (with Candi module attached) go to Vehicle Control Systems and then Class 2 Message Monitor…see what modules show “ACTIVE”…a lot of times the Throttle Position sensor causes Reduced Engine Power and in some cases can shut the engine down..I’d start the car and then clear all the codes and go for a ride and see if any codes appear before you shut the car down…any TPS issues also require a labscope to diagnose correctly…if the voltage from each of the 2 sensors just drop down a fraction of a volt for a millisecond the car will go into Reduced Power Mode…a labscope take millions of voltage samples a second and will be seen…if the “U” codes come back you or someone has to chase that !!

 

I cant find any"Class 2 Message Monitor" Yes, I do Ingition to run position and use Candi Modul.
From the beginning, Sart up push enter, F0: Diagostics Push Enter. Then 2005 Push enter. Passenger car Push enter. Chevrolet Push enter. Y Push Enter.
Now I come till F0 Vehicle Control System. Push Enter. I come to Computer/Intregrating System Push Enter. Then 4 speed Automaric Push Enter. Onstar not responding.. Press Continue on Soft4.
I have delete all Codes everywere. I'll take a test ride tomorrow if the weather is nice, and then check with the engine running to see if I can find any codes.



Continue once more Soft 4 Now see attached pictures.

 

If you can’t communicate with the VCIM Module (Onstar) you may have a communication issue…I don’t know where you are looking in the scan tool but go to Powertrain, Chassis, and Body and see if you can read live data in the modules…”Data Display”…if you can’t communicate you’ll have to further diagnose this…best to seek professional help !!…have you installed some aftermarket equipment like a radio lately or something you keep track plugged into the DLC (where your scan tool plugs into) ??…one of the members had a communication issue and his was his aftermarket radio he added.

 

Yes I can read Live data in the modules, I have an Aftermarket radio, and I have take away the fuse to On Star. We dont have on Star in Sweden Chevrolet has closed that för Europe! I take away Fuse after a lot of "Engine reduce power" maybe that was the problems. Nothing plugged to DLC.

 

You still have the VCIM module installed and being powered so it doesn’t matter whether you have it in Sweden and it’s being used…so you are saying you removed the VCIM module fuse and no more issues ??

 

I have only Take away OnStar fuse and nothing more.
Radio are aftermarket, yes I bought a new one .
I was out and check the Data Modul and I have living module I can see something happens when engine is running.
I saw also I have radio no comm. and GPS no comm you know that.
But I saw "Folding Top Module no comm. What is that. I have no Cab. I have Coupe.

 

If you don’t have a vert don’t worry about the Folding Top no comm !!…you don’t have that module installed…if it is an aftermarket radio you can try removing it…don’t know where you are located in Sweden but one of our C5 members is in southern Norway…username below…he may be able to help @oelarse !!

 

Thanks Rob for your confidence in me , but I am located too far away from Sweden to give any help with my diagnotic tool .
As far as i know it it the ECM causing the Reduced Engine Power and I would like see what kind of codes generated by the Engine Control .
When this happens GoranC6 should connect the Tech2 with the candi adapter to the car and select Engine Control first and report all DTC's appearing on the ECM module.

These alarms appear along the GMLAN(high speed) and not the Class 2 as far as I know ( My knowledge is on C5 not the C6 )
My experience is that both C5 and the C6 have some Historic DTC's regarding lost communcation between class 2 modules from time to time , but the don't cause any problems before the are Current all the time .

I would consentrate on the engine controle module to begin with .

 

I shall do as you say, I should connect the Tech2 with the candi adapter to the car and select Engine Control first and report all DTC's appearing on the ECM module. I shall do that after all rides I do with the car. It can take lång time before "Engine reduce power" dyker upp igen. I come back as soon as I get codes. Now we have very rainy weather hope its better soon, I want not to drive my car when its rainy.
I attach an Picture on my C6 I love that car.


ar!

 

Very nice car .

Hopefully you will catch some codes from the engine control that will give some more information to us ..
Please report back and all contributers to this thread will be notified when more info are added to this thread

 

hi my friend, i am having this problem with my 2005 model C6 vehicle, same as you. in my car's interior lighting it's illuminating irregularly to the lights. On top of that, when I measured the alternator, I observed voltages going below 13 volts. voltage current was moving very erratically. I'll try to have the alternator repaired tomorrow and I'll let you know if I solve the problem. And I'm following the thread here, I hope we get out of this situation

 

Today we took a 56 mile of ride to see if any codes came up, but no, no codes came up.
Everything worked as it should and no "engine reduce power" either.
On Saturday we are going to a Corvette meeting, with something around 190 miles of driving.
After that I check coder again with engine running.

 

Hi! Nice to hear you also have an 2005 C6. Sorry to hear you got problems with your generator.
Did "Engine Reduce Power" comes up for you too?

 

Hi Göran

Mikael from Stockholm. Have got the same problem as you and curios about how you solved the problem.

Felkod U2106
Service Traction Control
Only runs in a default mode.

/Mikael

 

Hi Mikael Code U2106 is Lost Communication with transmission control module TCM, BCM, EBCM.
Wash all the connections you can find and there are a lot of them. Lift out the car battery there against the outer fender, there are 2 large and 3 small. Wash spray and then contact spray Liquimoly I use. I think that's where I had the problem. I have not received ERP since then YET???
When you have wash. Take TECH 2 and delete all codes. Drive and check. drive and check then if you get new codes.
Then you have all the ground connections, 2 under the battery and one in front of the radiator on the right frame beam. Disassemble clean carefully reassemble. Behind the right front wheel inside the inner fender you have the TCM and ECM Clean all connection and Spray contact spray. I have did all that and all connection with Throttle body and Gas pedal and under the seats.

 

I was so happy, I thought my problems with ERP was over, I have drive a lot without any problems .....But today I got ERP again. I put in TECH 2 and find 3 codes.
1. U1000 as usual.
2. Driver Door module B1420.
3 . EBCM C0242 PCM indicated TCS malfunction.

 

Hi all

I want to say Thank you to you all who give me info about what the problems could be with my problems with Engine reduce power. I have did a lot of things to do with my car to get away with ERP.
I bought a new Throttle body and now ERP is gone!