BCM or ECM problems- need vettepert/expert help
Thread Starter
Cruising
Joined: Sep 2018
Posts: 11
Likes: 0
BCM or ECM problems- need vettepert/expert help
ok I’m an idiot. I know that. I cut the wires going to the XM Satellite Radio module in the trunk. I was trying to wire in a aux input. Yes I had the battery still hooked up. First sentence. After putting it all back together to test, I noticed a red blinking light on radio. I have not seen it before. I had just bought this 2007 base 3LT. A week earlier. This is my 3rd Vette to own. 1989 and 2001 were my others. I tried to crank car and got a clicking sound. No lights on dic either. I had both doors open, windows down and rear hatch open so I thought I ran battery dead. Charged it and nothing still. Light on door is red when I try to open it but it won’t open. So I reach in and pull emergency lever to gain entry. I put key in glove box slot and still no crank. I can hear the RCDLR make clicking sounds. No blown fuses relays. I towed to the only gm dealership within 100 miles. They don’t have anyone who knows vettes. The mechanic is ready to scream. We hooked up tech 2 and it shows no codes. It says no communication with ECM. The OSB port under dash only has power when every few minutes I hit the start button. We thought I unprogrammed keys so was gonna reprogram RCDLR. Can’t communicate with it so he says bad BCM. Purchased a BCM and same thing. Can’t communicate with it or RCDLR. He hooks computer up to tech 2 and car with the Chevy software and same thing can’t communicate. So he says ECM. Put that in car and same thing no communication. I said program ECM with vin then install it. He said they don’t have a way or adapter to do that. He said he didn’t program BCM either because they do it after install with computer. He has no other ideas of what to do. Like I said no dic on dashboard. Been over 2 weeks now and I’m so frustrated. Need help bad. Would a ECM I bought programmed already with my vin bring dic back to life? BCM? I know the wires I cut was power ground audio and serial data class 2 wire. I repaired the wires solder and heat shrink wrap.
Instructor
Joined: Aug 2012
Posts: 162
Likes: 40
From: Griffin GA
Many of the modules in the C6 communicate via a serial communication bus; i.e.the xm radio module, the radio head unit, instrument cluster, BCM, etc.
it would seem, that something that you did with the wiring has either interrupted that communication, or has damaged a module on that bus.
You may want to start by disconnecting the aux input.....
Is there any chance that you blew a fuse?
it would seem, that something that you did with the wiring has either interrupted that communication, or has damaged a module on that bus.
You may want to start by disconnecting the aux input.....
Is there any chance that you blew a fuse?
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Thread Starter
Cruising
Joined: Sep 2018
Posts: 11
Likes: 0
I disconnected battery 3 different times. I also undone the aux input and made sure the wires are back together. I felt like the security system has me locked out but can’t get tech 2 to communicate with car. Checked all fuses. The dic on dash is not lite up. That’s why tech won’t get into ECM or BCM or RCDLR on locks.
Burning Brakes
Joined: Nov 2014
Posts: 1,168
Likes: 458
From: Houston Texas
You may get a better response if you post this in the Z06 & ZR1 section. A lot of very knowledgeable people in there. Just explain you posted in the Tech/Per. section and didn't get much help.
Race Director
Joined: Apr 2007
Posts: 11,152
Likes: 890
From: South Western Ontario
Does other stuff work, like the radio, the key will open and lock the doors and the drivers door switch controls the passenger door lock and window??
Sounds like you still have the serial bus shorted. Try disconnecting the digital radio receiver at the star connectors.
https://www.corvetteforum.com/forums...connector.html
Heck, you can disconnect almost everything. I think you only need the VCM and BCM to get communications with the ECM to work. For the car to run you might also need the RCDLR. So you could disconnect the star jumpers and just jumper wire those 2 or 3 modules. I'd try the BCM and VCM first and see if the TECH2 can see the BCM and ECM then add more in and ensure the TECH2 can still communicate with the modules added.
I doubt it's the ECM or BCM. The dealer is just wasting YOUR money learning how to properly troubleshoot this type of issue.
Sounds like you still have the serial bus shorted. Try disconnecting the digital radio receiver at the star connectors.
https://www.corvetteforum.com/forums...connector.html
Heck, you can disconnect almost everything. I think you only need the VCM and BCM to get communications with the ECM to work. For the car to run you might also need the RCDLR. So you could disconnect the star jumpers and just jumper wire those 2 or 3 modules. I'd try the BCM and VCM first and see if the TECH2 can see the BCM and ECM then add more in and ensure the TECH2 can still communicate with the modules added.
I doubt it's the ECM or BCM. The dealer is just wasting YOUR money learning how to properly troubleshoot this type of issue.
Last edited by lionelhutz; Sep 28, 2018 at 09:21 PM.
Race Director
Joined: Apr 2007
Posts: 11,152
Likes: 890
From: South Western Ontario
They are not by the radio and have nothing to do with the radio wiring harnesses. Disconnecting the radio would not help for a wiring short, because the serial bus wiring is still all connected even with the plugs out of the radio meaning a short in the wiring will still cause problems. It would only help if the radio itself is shorting the bus.
The connector locations are listed in the thread I linked.
"Here are the locations of the two splice packs shown in the Class 2 diagram:
Splice Pack SP205 Instrument panel harness, in the passenger compartment, behind the lower left of the I/P on left side of steering column
Splice Pack SP208 Instrument panel harness, in the passenger compartment, behind the right side of the I/P to left of audio amplifier"
From that and the pictures in the thread, it looks like one is close to some wires passing through the firewall to the left of the column and the other is to the right of the console/tunnel.
They are a flat looking connector with a plastic strip holding metal pins that connect all the wires together.
Here is a link showing a C5 connector. The C6 should be somewhat similar.
https://www.corvetteforum.com/forums...post1580766038
I finished stripping the C6 I have, so I don't have a complete car I can look at anymore until I get everything back installed into the recipient car.
The connector locations are listed in the thread I linked.
"Here are the locations of the two splice packs shown in the Class 2 diagram:
Splice Pack SP205 Instrument panel harness, in the passenger compartment, behind the lower left of the I/P on left side of steering column
Splice Pack SP208 Instrument panel harness, in the passenger compartment, behind the right side of the I/P to left of audio amplifier"
From that and the pictures in the thread, it looks like one is close to some wires passing through the firewall to the left of the column and the other is to the right of the console/tunnel.
They are a flat looking connector with a plastic strip holding metal pins that connect all the wires together.
Here is a link showing a C5 connector. The C6 should be somewhat similar.
https://www.corvetteforum.com/forums...post1580766038
I finished stripping the C6 I have, so I don't have a complete car I can look at anymore until I get everything back installed into the recipient car.
Last edited by lionelhutz; Oct 2, 2018 at 01:10 PM.
Race Director
Joined: Apr 2007
Posts: 11,152
Likes: 890
From: South Western Ontario
I forgot to mention it, but f you remove the wire from pin A of SP208 then SP205 gets disconnected (which disconnects all the components on that splice pack) so you don't even have to get to it to see if it is a serial bus issue keeping you from getting the car to run unless you have to dig into that part of the wiring to find the short.
Read the schematic to see which pin is which device so you know what you're connecting or disconnecting.
Read the schematic to see which pin is which device so you know what you're connecting or disconnecting.
Last edited by lionelhutz; Oct 2, 2018 at 11:32 PM.