Hey guys, long-time lurker very rare poster here. Sorry in advance for writing a book, I appreciate those of you who make it all the way to the end!

I've been having problems with my '02 Z06 starting for quite some time and the local dealership and the guys at LG Motorsports aren't able to re-create it.

Naturally, because they can't re-create it they're having a hard time diagnosing/fixing the issue. I'm hoping someone can help me come up with some ideas or find a way to recreate the issue every time.

The issue is, sometimes the car won't start. When I turn the key, everything comes on in the cabin, but there's no response at all. There's no response at all that I can detect from the engine bay (no clicking of relays, no turning of starter).

Assuming a hill or a friendly stranger is nearby, I can always push start the car. A couple times, there haven't been friendly strangers or hills, or heinous speed bumps that wouldn't allow me to push start it.

When it won't start, I'm not getting any kind of DIC messages, odd behavior from the gauges, or flashing lights on the dash.

I've towed the car to the dealership a couple times. Typically what's happened then is once we get it off the tow truck, it starts up just fine doing nothing differently than the time before. I've learned now that I just wait and keep trying every 10-15 minutes until it starts up, usually within 2-3 hours, it has started back up.

I changed my battery back in April due to this problem (and others, my old battery was on the way out). On an unrelated (I hope) note, I also had the left side and right side daytime running lights replaced here recently.

Since taking it to the dealership and LG, we've done the following in the hopes that it'd fix the issue (even though they couldn't recreate it):

1. Replaced the ignition switch.
2. Deleted the VATS from the ECU/PCM

I'm currently stranded at my office waiting for it to start back up. I took a video with phone in the parking garage (see below) and I pulled the codes from the DIC and Googled them, I think that they seem to line up with replacing my battery and having to replace the DRLs. None of the other codes seem to line up with starting problems:

40-BCM -Body Control Module
A0-LDCM - Left Door Control Module
A1-RDCM - Right Door Control Module
A6-SCM - Seat Control Module
B0-RFA - Remote Function Actuation

If anyone has any suggestions on things that I can try, or ask a mechanic to try on my behalf, I'd appreciate it. Mostly, I'd like to figure out how I can recreate it so they can see what's going on, I know that's going to be the best way to get the problem fixed.

In the meantime, I'm scrounging around the office looking for some cleaning product to clean the pellet on my key, on the off chance it's just dirty.


Thanks for your help!

 

Sounds like another job for the amazing Bill Curlee. If it were me, I would have to look at the wiring diagrams to see what points I could check for voltage going to and leaving the ignition switch, both off and then in the start position. This will take 2 people, a good meter, wiring diagrams and someone that knows how to read them. Good luck, hopefully Bill will read your post and work his magic.

 

Sorry, I can't help you fix this. All I can say is I'm having exactly the same issue with my 2003 Convertible and it just surfaced a couple of weeks ago. Your video is perfect in that it shows the problem in graphic detail! I might add that I've even turned on my headlights and left them on while I turn the key to the crank position and the dash lights all go out (except for the "Check" light) while the headlights remain on and don't even dim. I've begun to think perhaps it's the starter on mine. I replaced the water pump a month or so ago and when I removed one of the hoses, coolant gushed out all over the passenger side of the engine compartment even though I thought I had drained all the coolant. Anyway, I'm thinking coolant may have fouled the connectors on the starter and that's why it's acting up now. BTW, my problem has also been intermittent in that a little over a week ago it did this, but then a couple of days later it was okay and the car started just fine. I had the battery tested this morning and was told it's fine. For the ignition switch to go bad is a possibility, but that coolant leaking out seems it more likely that created the problem.

 

I'm assuming you are pushing the clutch pedal down all the way and the interlock switch on the clutch pedal is working correctly?

 

Hi, I am no expert on these corvette's; however have you measured the voltage at the starting solenoid when in the crank positon to engage the starter. That is where I would look. Also, there have been a number of people who have reported the solenoid would not engage until they "tapped" it. Another item people have reported is loose connections at the starter. Let us know what you find at the starter solenoid.
Regards

 

I had the same issue. Super frustrating.... Turns out that a new key that I had made at the dealer was causing the problem (something to do with the chip in the key). I've now only been using the original key that I got from the previous owner and haven't had a problem since. Just a thought...

Hope you get it worked out!

 

Had same issue, replaced starter, fixed.

 

Was going to say, why haven't they replaced the starter?

Mine didn't start one day, I was able to get a long bar and tap the solenoid, started right up and has started ever since. Although I did buy a solenoid just to have on hand.

I realize they can't replicate it, but sometimes a semi shotgun approach is ok

 

Sounds like a bad starter. I had a similar issue with my other car, all lights come on but wouldn't start, i tapped the solenoid and it fired right up! It would start up on it's own every now and then and sometimes i would have to tap it. I replaced the starter and it fixed the problem.

 

2 likely causes are the starter/security relay or the starter itself. I'd think you could hear the relay clicking. If you're willing to do some testing yourself you could likely track it down fairly easily.

The easiest way to test is to get a wire with a ring on it and connect it to the solenoid. Tie the other end up by the battery where it is safe so it won't touch anything. Next time the car acts up just make 100% certain the car is in neutral then go under the hood and touch the wire to the positive battery post. If it starts then it's not the starter and you have to keep troubleshooting.

Here is a starter circuit schematic I found. I can't recall for sure but I think the relay may be on the firewall.

http://i45.photobucket.com/albums/f100/zingr/687833.gif

 

The schematic that lionelhutz provided is the KEY to solving your issue.

The THEFT DETERRENT RELAY is the heart of the cranking sequence. There are two sides of the relay. The CONTROL side and the power output side.

That relay is in the passengers foot well above the BCM on the fire wall. The relay will have FOUR wires.

First check all THREE fuses located in the I/P Fuse box #51, #52 and # 14

When you have all the safety circuits completed and the key in CRANK/START you apply 12 VDC to the control side of the relay. The BCM ground the Yellow/black wire when all of the security requirements are met.

When the control side gets energized it allows the 60 AMP 12 VDC power to go to the starter SOLENOID and the starter will run and crank the engine.


Things to check:

FUSES!
Main connections on the starter solenoid (Clean/ tight and not damaged)
Battery connections clean and tight. Battery terminal torque 97-2003 C5 torque to = 11 ft/lbs
Theft Deterrent Relay bad?

Is the SECURITY light on the IPC extinguished when you have the ignition ON?? If the security light isn’t out, you can’t crank the engine.

The resistor pellet on the key (VATS) needs to be read by the BCM to extinguish that light.

Bill

 

Reviewing your Vid again, I noticed that you still have the steering wheel locking motor active. (The Column Lock System)

It is STRONGLY RECOMMENDED that you get a Column Lock Bypass module and bypass that system. I recommend the LMC-5 Bypass.

One day you will go out to take the car for a ride and you won’t be going anywhere.


I also didnt see the security light when you had the ignition ON.

Another common C5 starting fault is a bad starter solenoid. If you have someone hold the ignition in the START position, rap the starter and if the solenoid is the cause the mechanical agitation will usually cause the starter to crank.

 

Lo and behold...today I went out and had my wife sit in the driver's seat while I pushed the car a foot or so backward toward the edge of the garage. My plan was to let it roll in reverse down the driveway and pop the clutch to get it running. We changed places and just for the heck of it, I tried to start it and it fired right up! The only thing we did--aside from moving it a foot or so--that I haven't done previously is move the seat all the way forward so she could reach the brake pedal.

 

^^^^^^^^^^^^^^

This.

 

Bill, I believe I've read earlier posts where you've described rapping the solenoid on your own car to get the starter to engage.

Although I thought my no-crank problem stemmed from something going on in the wiring under the driver's seat, today, the starter failed as usual and I hadn't moved the seat since yesterday when it started okay. So this morning, when I got the no-crank response, I tapped the solenoid with a long metal pipe and thereafter it started right up.

Tomorrow, I'll begin the process of removing the starter. I have long-tube headers, so I'm not looking forward to this. At the same time, I fear the dreaded starter breaking off a portion of the block nightmare that Junkman and others have experienced, so I'm primed.

 

Hard to believe the "guys at LG Motorsports" didn't suggest this as the solution.

 

Removing it doesnt breake the block. Its a back fire during starting or a hydrolock situation during starting.

I suppose a loose starter bolt over time could also cause it to snap. Follow the torque recommendations and purchase the two long bolt starter.

Bill

 

I've replaced starters for this issue and have had luck.

Also consider ign switch and ign relays.

 

Roger that. I was inferring that despite the prospect of a PITA project, replacing the starter now hopefully accomplishes two things: it resolves this frustrating no-crank business and given that I will replace the problem unit with the design that requires two long bolts, I can breathe easier that I've saved myself from the broken block fiasco.

 

For everyone's information,

I too am experiencing this similar problem. Just wanted to add another symptom. When I turn the ignition switch, nothing happens except a humming sound which I believe is the electric fuel pump. After pushing the car backwards to load it up on a flatbed, then trying to start it again just for grins, it started right up. Also, could moisture on the ignition key cause a problem with sensing the chip in the key?

Carcrisis