Lately I have noticed my FOB has had weird issues communicating with the RCDLR, then last night I started the car. It fired right up as usual, but then then Start button began flashing a sequence of quick flashes between the red, yellow and green lights for Off, Acc, and Start. The engine was running, but the starter would not disengage. Nothing I did would stop the car, so in order to save the starter I popped the hood, got out and pulled the relay from the fuse box in the engine compartment. If I replace the relay, the stuck on condition continues whether the FOB is in range or not.

Not gonna lie. The helpless feeling I get when I hear the grind and smell the overheating starter is brutal.

 

I'm not a professional, so this is based on my old Chevy Nova. It is the starter solenoid and/or the mechanism that retracts the starter gear.

My SWAG (Some Wild *** Guess)

ttt

 

Sounds like the #43 crank relay is stuck on. Try swapping with the #45 wiper relay and see what happens.

 

Thanks for the help! It seems we think alike, because pulling relay 43 was what I did to stop the flow of current to the starter. When I swapped relays, the starter engaged again instantly. As I look further into this problem, it seems like something is stuck on an even lower level, because all the lights in the car are stuck on. Everything comes on and stays lit, doors don’t lock, windows are stuck up at least, lol. I have the ACDelco service manual and I can’t seem to find any guidance on this exact issue yet, but I know I will find something somewhere eventually.
The suggestion from Dutch08 in the first reply on the thread is something else I considered early in the troubleshooting process, which is that the starter solenoid could be stuck on. But I will admit that getting to the starter on this car is something that is probably the last thing I ever want to do so I’m procrastinating like crazy on it. Plus, due to some other behaviors the car has had leading up to this failure, I have a gut feeling there is an issue with connections in a wiring harness somewhere. Admittedly, that could be an even tougher task than changing the solenoid by the time all is said and done, so if anybody out there has a reason why I should go after the solenoid first, I am open minded.

 

Sorry, I misunderstood. Thought you had only reinstalled the original crank relay, not switched in another one.

If the starter runs without pushing the button no matter which relay is in the #43 socket, that means something is activating the trigger circuit for that relay. Verify that with your digital voltmeter, then consult your shop manual to find out what exactly happens when you press the start button. Find the problem and fix it

Here's a couple of WAGS (wild *** guesses):

(1) Throw parts at the problem:
Maybe a bogus start switch is sticking - replace the switch
Replace relay #43 with a new relay

(2) Hail Mary pass & hope for the best:
Maybe the ECU has become confused. Try a hard restart: disconnect the battery for a good 30min - 1 hr. Before reconnecting the battery cables, touch them together to remove any residual voltage and make sure the ECU is dead. Then reconnect the battery and see what happens.

Really don't have a clue without seeing the car and using test equip. Very interesting problem, good luck and let us know how it works out.

 

Thanks a bunch! I didn’t mention earlier that I had done a reset on PCM, but I will admit that I let it drain for about 20 minutes, not an hour as you suggested so I will give that another go. I feel like it might be a bad start switch, but then it seems like a stuck start switch shouldn’t be a problem if you are coming out of a reset and the fob is out of range because a failed RCDLR security check would disable the crank circuit.

 

I think yours might be experiencing some of the same symptoms that happened to mine. It would start and this awful grind sound coming from the starter and voltage going crazy. It would not do it all the time but when it did it acted like the engine would not shut off. I ended up replacing the starter and the issue was resolved. It seems that the closeness of the starter to the exhaust manifold and or headers cause them to go a little crazy. It wasn't too bad of a job. dropped the cats and removed the starter. Went ahead and replaced the crankshaft sensor while down there since it is right behind the starter.

 

You may need a new starter. My friend's 2008 had a starter issue caused by the housing where the leads mount being cracked and exposing the leads. His car did opposite of yours and would not engage. It's a tight fit but not a bad swap if you can get your hands and fingers in there.

 

Thanks for the suggestions, this is such a great forum. I changed the ignition switch and ended up with the car in immobilize mode, horn honking, red light flashing. Then that night my body went into the same mode as I got hit with a Covid variant. Wowza! The car has been the least of my worries. Two days ago my wife broke quarantine to give me the box I got in the mail, which is a new starter solenoid. I can’t wait to open it. Actually I can’t wait to feel good enough to open it. Lol

 

I began by replacing the ignition switch. Cheap and easy fix, but it didn’t fix the problem. So I replaced the starter. A dealership replaced it 2 years ago, which was unnecessary at that time. Makes.my blood boil bringing that up, but hey, no need to add to dealership hate here. Plenty of that already, lol. I removed the starter, inspected it, and found the inside of the solenoid was melted and appeared to have caused it to be stuck. Bingo! I found the problem. So I Replaced the whole unit and added a heat shield. While waiting for the part to arrive I did an extensive clean up of all the grounding points on the car, which was educational. Some were dirtier than I expected. I also cleaned the fuse blocks under hood and passenger floorboard. Checked and tested very single fuse and relay. They all looked good and tested good, which was nit surprising because I had done just last year. I removed the battery, tested it and fully charged it. It’s a year old red top, I took it to Advance Auto where they have the latest device, and it performed a tiny bit better than a brand new one of the same model. Oddly, I was almost wishing the battery had been the problem, since it seems to be the default fix for every Corvette problem in this forum, right? I love this forum and I’m joking, sort of, but I think we all should know by now that the C6 is a battery beating bastard of a beast.
When the starter arrived, I installed it and was not entirely surprised when I discovered…..
That did not fix the problem.
The instant I reconnected the battery cables, the security system activated the horn honking and the starter began cranking. What??? How is the run crank signal going when the immobilizer is active? The ignition was not on so the engine didn’t begin running, but I had to pull the relay to get the crank signal to stop. I waited for the ECM/BCM to time out, which it did, so I reconnected the relay. The crank signal had stopped. Cool. I got into the car and tried starting it. Everything was dead.
I went back through the process and double checked my installation of the ignition switch. I found that the harness had not fully seated in the new unit and put it back it place.
Now the system comes back on line and sort of works. Doors, windows, wipers, radio are all dead, although some of them just randomly activate without any input from me. I can’t get a scan tool to work properly. I get errors saying the data is bad.
So, it’s looking like I have a bad BCM. It feels weird to say this, but I pray to God I have a bad BCM. I just want the next repair to be the right repair.

 

Slackmaster, what did your problem end up being? I just pulled in, turned off the car and the starter, started turning over the engine. It did not stop, till the battery was disconnected. Battery is now about dead. Be surprised, if I didn't damage the starter, while I was getting the right/wrong size wrench. 9/16 not 10mm. WTF! I have a 2-3 year old rebuilt starter w/heat wrap on solenoid and coated headers. Starter wires also have heat protection.

 

Did you check the crank/run relay on the bottom of the BCM to see if it was burnt in the open position?

 

Yes I did check that out. I also went a step further, and I disassembled the BCM and checked for any burnt or corroded on the PCB. Everything was cool, I put it back together and reinstalled the BCM. I went to start the car, and basically NOTHING electronic worked. After a change of underwear, I hooked up a freshly charged battery and just let it sit for a while. Eventually the various modules all came back to life, with the exception of the drivers door module. After a few test drives while using a OBDII scanner and recording the output graphs, I noticed some weird stuff happening intermittently in random areas. That resulted in many hours of education on how the CANBUS system works, which lead me to test for a short to ground by measuring the resistance between the data hi pin to and data low pins of the DLC. That’s a great test to know about, because it takes away a lot of guesswork. Unfortunately not all the guesswork, but enough to make it a tool worth knowing about. Plus it’s a test that works on any CANBUS network whether it’s on a car, truck, boat, guided missile, arcade game, whatever, they all have the same foundation.
That test gave me the confidence to know that after I had thoroughly cleaned every grounding post on the entire system yet I still had a short to ground, I needed to look for a damaged wire somewhere. At this point I was wishing I was AntMan, because I am way too big to fit into the spaces where all the wiring lives. But anyway I found an area where a wire bundle on the drivers side behind the IPC comes from the engine compartment through the firewall. There is a big piece of rubbery fascia with a hole in it where the wires come through. The fascia is held up in the chassis with some adhesive, which has lost its grip over the years so that now this piece of fascia, which views a few pounds, has just been sawing away slowly at this wire bundle, eventually cutting through the insulation and exposing wires in the bundle. all the wires in this bundle are attached to one of the two 120 ohm terminators that are crucial for maintaining data integrity on the CANBUS network.
So after making that wiring repair, and some mods on the fascia to make sure it won’t damage the wire bundle again, I tested the CANBUS for resistance and voila! Perfect reading of 60 ohms. Since then I have made several test drives and everything on the car works like new, almost. the drivers side window, mirrors and seat position memory are not working, but the interior and exterior door lock switches all work fine. My scanner tells me the Drivers Door Module is non existent. .
I’m still trying to find the issue there. I am stubborn about buying new parts until I am absolutely certain that’s what has to happen. The drivers door module is built into the window regulator and costs about 350. I can see myself buying and installing a new one and still having the exact same problem. Before I order that part, I’m going to unbundle and inspect all the wiring in the drivers door to find the culprit. My biggest fear is that I will find no damage to the wiring, which means I will then need to figure out whether the problem is in the BCM or the DDM, or god forbid both BCM and DDM.
So one of the things I think is really important for others to be informed about,, is the eventual failure of the adhesive that holds up the fascia where the drivers side wiring bundle is tunneled through the firewall. It is an issue that will likely present itself very slowly and is difficult to track down because a problem located right next to a terminator can potentially affect any other electrical system in the car. I suspect it has already caused problems for a shitload of C6 owners. When there is a short in the CANBUS circuit, the issues that result will often be intermittent or otherwise difficult to troubleshoot.

 

Great post, thanks for sharing your experience. It's very helpful when people tell how they solved a tough problem. Could you post a picture of the fascia that came loose and caused all the trouble? It may well be the cause of some other hard to diagnose electrical problems we hear about as C6s get older.

 

How many miles on the car ? Just like to know when to expect a similar problem.