When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
So i believe i have multiple issues just dont know if they relate or not and it all seems electrical.
-Car was parked with no issues other than cant go in reverse with car running. Went to crank it after a few weeks and dead battery. Charged battery and all lights,radio windows all work, try to start and just a click and dash goes black for a few then comes back on and gauges sweep and sometimes the security light will set. Replaced battery and same things happen.
-i tried checking codes and at first it would not connect, randomly it will scan and then wont. last time it scanned it had codes u2100, P0335 and P0340. tried clearing them and goes to link error everytime.
-checked fuses and crank relay and reseated bcm connectors as well. any ideas?
2005 corvette 6spd manual.
Last edited by eisworthr; Sep 7, 2022 at 09:39 PM.
Best to fill out your profile so we know what year, manual or auto, any mods, tune ??...the U2100 is a communication issue and what's probably keeping the car from starting...the 2100 involves the ESC,BCM,EBCM and TCM which are all on your GM LAN...the high speed bus...just by you mentioning the trans won't go into reverse MAY mean a bad TCM...the pan will have to be removed to change the module...you will also need to program it…and this is just a guess !!...also this may be a wiring issue with the comm lines but could also just be a bad module...to diagnose a wiring issue there are 2 120 ohm resistors at each end of the high speed LAN...one in the BCM and the ECM...if you take an ohm meter and connect it to pins 6 and 14 at the DLC (where your scan tool connects to) you should see 60 ohms if the wiring is good...if you see 120 ohms...BAD !!...make sure the battery is disconnected when doing this.
whoops sorry about that i didnt realize i didnt put any information on the car itself. its a 05 c6 it is a 6 speed. ill have to go look at adding on my profile i havent played in that section yet. i plan on playing on mitchell 1 to get diagrams and more info itll just be friday before i can was hoping someone may have some ideas i can look into prior to the weekend. thanks
whoops sorry about that i didnt realize i didnt put any information on the car itself. its a 05 c6 it is a 6 speed. ill have to go look at adding on my profile i havent played in that section yet. i plan on playing on mitchell 1 to get diagrams and more info itll just be friday before i can was hoping someone may have some ideas i can look into prior to the weekend. thanks
If it's a M6 strike the bad TCM...I use both Mitchell and Alldata...Alldata DIY is MUCH better in my opinion...way more info...you can get a months sub for around $20.00 I believe. Can you access all modules with your scan tool and see who you can or can't communicate with ??...may help in a diagnosis...I'd still get the ohm meter out and check the comm wiring
I had that problem when putting my 2008 back together. Eventually, I jumpered the starter relay wires. The starter turned over.
Once I got that far, I took the cover off of the relay so all I had to do was push the relay down to get the starter to turn over. The car would start and run.
But at that point I had to find out what was keeping the relay from getting the energize signal. I think the security system was doing it. I think all I had to do was reset the security system to get it to work.
Sounds like something similar that happened to me just yesterday. driving all day, came out of store and car wouldn't start. Everything else works but when you go to start it nothing and everything goes dark. First thing I checked was the battery and of course the ground was loose. So I pushed it on tighter and just went home, I wasn't far. Tightened it up same thing no start. Took the ground back off to take closer look and the brass connector is held in place by this weird bracket under the plastic housing and that was loose also with a little surface corrosion.
Took it apart and wire brushed the surfaces and tightened everything back up and now it's fine.
You replaced the battery just maybe take a GOOD look at that ground connection.
Sounds like something similar that happened to me just yesterday. driving all day, came out of store and car wouldn't start. Everything else works but when you go to start it nothing and everything goes dark. First thing I checked was the battery and of course the ground was loose. So I pushed it on tighter and just went home, I wasn't far. Tightened it up same thing no start. Took the ground back off to take closer look and the brass connector is held in place by this weird bracket under the plastic housing and that was loose also with a little surface corrosion.
Took it apart and wire brushed the surfaces and tightened everything back up and now it's fine.
You replaced the battery just maybe take a GOOD look at that ground connection.
yes I checked them well battery connections are good actually almost brand new, thanks a lot of times the simple things like that are overlooked.
Got diagrams and tested yesterday and replacing the starter tomorrow. I still have no fix on the wierd canbus actions but they’re gone for now so hopefully this will get it running I’ll know hopefully tomorrow
yes I checked them well battery connections are good actually almost brand new, thanks a lot of times the simple things like that are overlooked.
Got diagrams and tested yesterday and replacing the starter tomorrow. I still have no fix on the wierd canbus actions but they’re gone for now so hopefully this will get it running I’ll know hopefully tomorrow
How do you know the starter is bad ??…you can jump pins 87 and 30 at the starter relay and see if it cranks.
checked voltages across the whole starting circuit and jumped the pins as well all fail at the starter. should have the starter first thing in the morning and get it swapped then assuming all is well im gonna start diving into the reverse issue, i havent drove it much lately because of that.
well she purrs again, drove around today and no more codes. didnt expect to have to remove headers just for a 1/2 clearance for one bolt changing a starter, luckily all bolts came out smooth
electrical issues? no crank/start
