Help,my Matco scanner is telling me I have no comm between BCM and VCIM and also no comm with the ECM. Cannot find the VCIM.It is supposed to be on the inner right back fender but it isn't. Some sites say it is under the waterfall. Can anyone tell me or send me a photo of what it looks like. I see the BCM under the waterfall but am at a loss to see a VCIM? Stopped tearing panels out at that time because I'm befuddled.I had a dealer tell me that my car doesn't have one. Seems awful funny that EBay has lots of them for sale. Help !!!

 

What is the code NUMBER?
Does the car have OnStar and/or XM/Sirius? That is what the VCIM does. OnStar would be on the rearview mirror.
The computer modules are connected in a daisy chain; if one is not working none of the downstream modules communicate.
That fault usually means a bad fuse or wire. Does your front cig lighter work?

 

How is your scanner talking to you if it can't communicate with the ECM/PCM?
What module are you connected to?

 

Hi y'all,sorry I hadn't got back to this before but we have had some family issues.Im going to have to get a hold of the gentleman with the scanner as I have lost the notepad with the code number on it.I was going through the OBD port to his scanner and it told us no communication to the BCM and ECM. Sorry I can't be more forthcoming but I'm very dumb about all of this computer stuff still.At 71,and coming from aviation mostly I never really had many feelings with it I'm learning fast now. Now that I believe I can navigate this site now I will try to do better I did find someplace last night that told me the VCIM is behind the dash close to the steering column. Will be able to check that maybe this coming weekend. Daughters car is in the garage now and I'm repairing her curb strike damage.

 

Okay,the code was U2106 and I just discovered that it really says ,no comm with TCM. What is happening is car started,ran maybe a minute,died and when I went to restart ,it does nothing All dash lights are lit until you go to start position with key at which time all lights on dash go out and nothing happens. I was under the impression that the VCIM is the hub that all modules talk to each other through. Maybe that is bogus info? Old man is really confused here so any thoughts or help is muchly appreciated. TIA!

 

I’m sure you will figure it out, I suggest you inspect the TCM connector for bent pins or pushed back pins, unlikely but possible, also have a look at the fuses and relays in the under hood fuse box, push them in to ensure they are fully seated in their positions. While you are there tighten those 4 bolts, they are 7mm and must be tightened very tight!


These four bolts, notice we haven’t spent any money on parts yet! Just simple things that can cause this communication problem.

 

For HHR, U2106 is specifically described as “Lost Communications With Transmission Control System.”

Low battery voltage, bad grounds, and poorly seated fuse panel are all common causes of computer module communication problems. Before you do anything else, check the voltage at the battery. If it’s less than 12.5V, charge it and verify that it will hold that charge. No point trying to diagnose an electrical problem with a bad battery.

 

Where ever you found that the VCIM is behind the dash near the steering column is really bad information. Don't believe anything from that source. If you have OnStar the VCIM lives behind the right rear quarter panel trim. The VCIM is only for voice communication.
The module network has no "central hub"; it is a daisy chain thing. I think that the idiot you heard that information from meant the BCM, it is the inside fuse box on the passenger side below the radio.
Lack of communication between modules is usually a wiring thing or a fuse thing. Look at all of the wires going to the TCM. The TCM is the smaller of the 2 modules under the plastic hood in front of the under hood fuse box.
There are links in my sig to Owner Manuals and Shop Manuals. If you are viewing the Mobile Site, scroll all the way down and choose view full site (or something like that).

I will be 74 next Monday, had a heart attack last September. Age is no excuse.

 

Okay the gentleman with the scanner finally sent me all the codes. They were U0073,U2108,and U2111. Hopefully someone will know something about my troubles.

 

To Donbrew. Not using age as an excuse. I had no desire to learn any of this before. But I have had my own health issues,plus a radical income shift,all of which left me in a position that I'm forced to learn it. So I'm doing as well as I can,and will figure out all this eventually.