No start then start issue.
Thread Starter
Burning Brakes
Joined: Aug 2018
Posts: 891
Likes: 175
From: PA
No start then start issue.
Just this afternoon I went for a short 10 minute drive in my 91 ZR1. Stopped to eat local and after sitting around 45 minutes it wouldn't start. By no start I mean nothing when the key was turned to start. I had plenty of battery power to work windows and such. Battery was just replaced last spring. I set the security system and the alarm went off when door opened. Security blinked and stopped blinking when ignition was turned to start. I tried both sets of keys and nothing. I checked the fuses and found nothing.
While I was talking with someone at the ZR1 Specialist at Haibeck Automotive. I had my son try the ignition again. It roared to life like there was no problem at all. We drove home a few miles away about 10 minutes . Parked in the garage , shut it off , and it restarted right up. Not sure what's going on. Don't think it's the VATs . Neutral safety switch? The guy at Haibeck thought maybe my starter . The car sits and usually gets driven less than 3000 miles a year. This year not even 500 miles. It's always parked inside the garage. Maybe mice or chipmunks as that's what we see around . Car is around 54 k miles. Before I take the plenum off I would like to try a scope and have a look. If I see mouse or rodent bedding then I'll go down that avenue.
While I was talking with someone at the ZR1 Specialist at Haibeck Automotive. I had my son try the ignition again. It roared to life like there was no problem at all. We drove home a few miles away about 10 minutes . Parked in the garage , shut it off , and it restarted right up. Not sure what's going on. Don't think it's the VATs . Neutral safety switch? The guy at Haibeck thought maybe my starter . The car sits and usually gets driven less than 3000 miles a year. This year not even 500 miles. It's always parked inside the garage. Maybe mice or chipmunks as that's what we see around . Car is around 54 k miles. Before I take the plenum off I would like to try a scope and have a look. If I see mouse or rodent bedding then I'll go down that avenue.
Drifting
Joined: Apr 2020
Posts: 1,925
Likes: 610
From: Orange, CA
If you turned the key and got literally nothing whatsoever, you have two possibilities (as far as I am aware; take note however that I've never worked on an LT5):
1. The CCM is not allowing a start condition due to VATS. If this is the case, the SECURITY light will come on solid when you try to turn the key, to indicate that you are locked out due to an improper key resistance value or missing resistance value. You say that the SECURITY light went out, which would seem to indicate VATS is detecting your key correctly and the CCM is correctly allowing a start condition. So that brings us to...
2. Starter failure/intermittent. The "click" and heavy power draw when you click the key to start is the starter windings. If you get no click and no power draw, but the CCM is commanding a start, then the starter isn't drawing that power for some reason. Either the wiring to the starter is poor/dirty/loose, or the starter itself has started to fail internally.
You can of course also check codes (https://tech.corvettecentral.com/201...trouble-codes/) but if it's the starter, there won't be any codes stored as the computer has no way of knowing the starter isn't doing what it's being told to do.
Best of luck!
1. The CCM is not allowing a start condition due to VATS. If this is the case, the SECURITY light will come on solid when you try to turn the key, to indicate that you are locked out due to an improper key resistance value or missing resistance value. You say that the SECURITY light went out, which would seem to indicate VATS is detecting your key correctly and the CCM is correctly allowing a start condition. So that brings us to...
2. Starter failure/intermittent. The "click" and heavy power draw when you click the key to start is the starter windings. If you get no click and no power draw, but the CCM is commanding a start, then the starter isn't drawing that power for some reason. Either the wiring to the starter is poor/dirty/loose, or the starter itself has started to fail internally.
You can of course also check codes (https://tech.corvettecentral.com/201...trouble-codes/) but if it's the starter, there won't be any codes stored as the computer has no way of knowing the starter isn't doing what it's being told to do.
Best of luck!
Thread Starter
Burning Brakes
Joined: Aug 2018
Posts: 891
Likes: 175
From: PA
I read a thread about the VATS resetting itself and taking anywhere from 8 -15 minutes. Some have said even longer. I believe that when the key was turned to the first position the LCD display was visible but went out when advanced to start. I'm not sure about the security light flashing before I actually set the alarm and opened the door to see if it would go off. I tried to see if the interior lights would dim when turning the key to start but they went out prior to trying it. That's when after maybe 15 or 20 minutes it started right up. This is the first time a C4 I owned failed to start from anything other than a weak or dead battery. I had a 96 coupe no start issues, and a previous 91 ZR1 . I can't remember if it had the VATS bypass but it had a neutral safety defeat by the previous owner.
Drifting
Joined: Apr 2020
Posts: 1,925
Likes: 610
From: Orange, CA
If it's not doing it now, just keep an eye on it. If there is a next time when you turn the key and nothing happens, hold it there and make sure to look at the SECURITY light. If VATS is the culprit, that light will be on solid. It goes out when the correct key is inserted and turned.
According to my FSMs (note: 94-95), the VATS lockout is 4 minutes.
EDIT: According to my FSM, the ZF6 transmission does not have a neutral safety switch. Only the automatic transmission has a Neutral/Park switch.
According to my FSMs (note: 94-95), the VATS lockout is 4 minutes.
EDIT: According to my FSM, the ZF6 transmission does not have a neutral safety switch. Only the automatic transmission has a Neutral/Park switch.
Last edited by Nomake Wan; Oct 7, 2020 at 09:02 PM.
