Hey all,

new here and have been banging my head on the wall with my 2005 c6 6mt car, thought I’d ask the experts for help.

Car was running great with no issues a month ago. I moved down to vero beach Fl from Orlando and I left the car at my buddy’s house for a month. He drove the car to work with no issues…. His wife went into the garage and mentioned that the dash lights were on at night, and so my buddy put the battery tender on. Drove up to Orlando this past weekend with intentions of picking it up, and when I go up there the car wouldn’t start. Disconnected the battery probably a dozen times, and the car was stuck in accessory mode and wouldn’t come out of it. After reading on forums for a couple hours, I tried someone’s suggestion of removing fuse 11 in the engine bay. When I reconnected the battery, the horn now honked like it usually did. New problem now is that intermittently the dash lights would come on and gauges would sweep, but car wouldn’t start, other times I would get a steering lock message (there is a bypass in it less than 2 months old) and other times I would get “no key fobs detected”. Every time I would try to start it, I got a different message it seems. Got frustrated and left back home. Just paid a bunch of money to get the car down here today. Tried a second key, now the car just says no key fobs detected, doors won’t open, locks won’t work, etc. pressing the ignition button does absolutely nothing. Battery is 2 months old and fully charged, so I don’t think it’s a voltage issue. At this point I am at my Witt’s end, and not sure what else to try. I know an individual by the name of Dano523 is the electronic guru around here, and so I decided to join and seek some help. Thoughts anyone??? Yes, I tried putting the key in the glovebox slot as well, no change. Help!!!!!

 

Would try the battery disconnect, but this time with cables off the battery, touch them together to fully drain the modules, the reconnect fully charged battery to do hard reset on all the modules.

Now if you are still having problems, then with car in park/neutral, pull the starter relay and try to jump out the relay to see if the starter will crank the motor.

If yes, then problem is up line of the relay, while if No the starter will not crank, then problem is down line of the relay, with either terminal on starter solenoid nut loose, terminal cracked off, or just solenoid gone bad and needs to be replace (replacement solenoid is about $25).

In this photo, you can see the terminal that is cracked off the solenoid,


As for problem is up line of the engine bay fuse box relay, not in the wiring between it and the BCM, could be that the run/crack relay on the bottom of the BCM has gone bad,
Dotted line means bottom of BCM


Or could be conditions for the end to start, has not been meet.
So once starter button is pushed to start the car (and it not having problems) RCDLR has to show the Fob in the car (or in the slot), and the clutch pedal switch on the floor board, has to send the continuity that is fully pressed.
Note here, without just throwing parts at the car, you can put a Tech II on car to pull up BCM data, to check the above items to start with to see if a problem with starter switch, clutch pedal switch, and even BCM to see if throwing start command, but crank/start relay bad.

If problem turns out to be RCDLR, somethings it as simple as corrosion on the pins or connector that is causing the problem, while other times it may just be a head pins that need to be re-soldered, do to cold solder joint/someone driving the car in rough road conditions to exacerbate the problem with the cold solder joints.

 

With all those strange things you are seeing screams communication issue (high or low speed CAN) to me and this applies to all domestic and foreign cars these days too…do you have a DVOM and know how to use it and do you own even a cheap “code reader” ??…a scan tool whether it’s a factory level or aftermarket that can scan all of the cars modules will help better to diagnose this…so the car is not stuck in ACCY mode currently and do you have ignition function ??…ie all modes work
??…if electrical testing is over your head go north to Melbourne and go see Brin Kline over at Assured Auto…he is a very sharp “diagnostic” tech…general repair shops or dealerships will have no clue where to even start to diagnose this if that is what this is and will only replace a bunch of parts and if that doesn’t work the car will sit there for weeks or months…was the car stored outside or in a garage ??

 

So after screwing with the car for 3 hrs last night and trying everything you guys suggested, i happened to go back and look at the fusebox to check the #11 fuse that i asked my buddy to remove and replace. Lo and behold, the fuse wasn't there.... So i put the fuse back in, and all functions were restored. Just this morning i went out there and the car started right up like nothing every happened.

So i called my buddy up and had some choice words for him. No explanation why the battery died, nor why the car locked up in ACC mode like it did, but i honestly wouldn't be surprised if he forgot to put the car in reverse when turning off after i warned him multiple times, and set off this series of events. I will keep an eye on it, but for now, by all appearances, it looks like it's fine. Thank you everyone! Next thread will be why i have a "ghost" driver's seat that likes to move on its own when i sit in in. I checked the wiring previously and it was fine, i have a suspicion it's the module as the seat is sagged and presses on it when i sit in it. Thank you everyone!