Hi Guys,

Over the last year or so, every once and a while I'll go to start my Monte (2001 SS) and it will refuse to crank. When I put the key in, all the gauges will come on and the normal things show up in the message center, but when I turn the key, nothing will happen (the car knows the key was turned because the lights, gauges, and radio will shut off, like they do normally). The car won't even attempt to crank (I hear relays clicking in the engine bay but I'm not sure which ones). I'm almost certain it isn't a battery/charging system-related issue, because the battery is only a year old (I replaced it the first time this happened). The battery gauge reads a solid 12.5V while this is happening, and the needle doesn't move at all when I turn the key. Luckily this usually happens in my driveway and hasn't been a huge issue, but the car is my daily driver and I really can't afford to not have it when I need it. Usually after letting the car sit for a while the issue usually goes away, but it's very sporadic. I've tried replacing/swapping fuses/relays, a new battery, testing the alternator, and I just ordered a new starter but haven't installed it yet. This is a really tricky issue to track down. The previous time this happened, the issue went away after trying to start the car 3 times in a row. After putting the key in, turning it, and taking it back out, the third time got it.

A little over a year ago, I was having a serious (1/3 car starts) issue with the PassLock system (similar symptoms of no cranking but the security light would flash when trying to start). After waiting with the key in the "ON" position for 10 minutes the car would always start. I got a new key made by the dealer, replaced the lock cylinder with this: https://www.amazon.com/gp/product/B002YMDMZC/
and the issue went away. I haven't seen the dreaded flashing security light since.

Today my car didn't want to start in my work parking lot, and I figured I would try the same thing, even though there wasn't a security light (I just had a hunch). Maybe it was just a coincidence but after 10 minutes of sitting with the key "ON" the car started right up. When the car starts normally, the engine only needs to crank for about a second, and this was no exception. This led me to believe the battery had plenty of juice.

I know the passlock issue is well known, but I've never heard anything about this issue, even after a lot of googling. The next time this happens in my driveway I'll get under the car and see if there's a start signal at the starter motor. In the meantime, is there anything that might be causing this issue? Aside from an aftermarket radio, the car is 100% stock and never gives me any other issues. I really can't track this issue down for the life of me, and I'd prefer not to just throw money at the problem.

I really appreciate any insight that you guys have!

 

The pass-lock bypass for the aftermarket stereo could be a problem, but it also sounds like a classic case of a worn/dirty/corroded ignition switch housing. This problem is becoming more and more common as our cars age. Symptoms vary, but can include the ones you've described plus some others like turn signal, headlight and dash light malfunctions. No practical way to test other than removing and inspecting internal points/contacts, or just cut to the chase and replace it with a A/C Delco (OEM) one. The aftermarket ones tend to have issues.

Here's a couple of videos:

1.
2.

 

Cool, I'll take a look at the cylinder contacts and clean them out if need be. The car has almost 200k miles so it makes sense that those might be worn out. I don't think it's the radio because I've had the radio for 4 years and these problems started around a year ago. If that doesn't do it I'll bite the bullet and just get all ACDelco parts and replace the ignition switch housing and maybe the cylinder again. Thanks for getting back to me!

 

Your welcome.

Good luck, and please keep us posted.

 

So I just took the ignition switch housing out of the car and cleaned all of the pressure contacts that are mentioned in the second video, they were pretty dirty. It hasn't given me a problem yet today but I'll keep a close eye on it. If the issues persist I'll order all new ACDelco parts for that system.

Thanks again for the insight!

 

Thanks for the follow up.
Keep us posted.

 

So today it happened again. I had some time to troubleshoot (and some inspiration from Youtube) so I popped the drivers-side fuse cover off, pulled the BCM/CLUST fuse, attempted to start the car (nothing happened), put it back in, and the car started without a problem. It may have been a coincidence though, because in the past I've tried disconnecting and reconnecting the battery to solve this problem with no success.

Does this add any new insight? Hopefully it isn't a BCM issue.

 

Recently has similar issues with my 97 monte ls. Found out it has an aftermarket security system. If I unlock using the manual keys it will only make a strange consistent clicking noise coming from the fuse box under the hood, and will not start (I can remove and reconnect fuses or disconnect and reconnect the battery and it will start and ruin fine). However if I unlock the car using the keyless entry it will start and run perfect. Hopefully this helps in some way.

 

As hunterh047 mentioned, it could be a problem with the aftermarket passlock bypass if you have an aftermarket radio, but this is also one of the many symptoms of a bad ignition switch. I don't think it's the BCM.

Another posibilty is the ignition lock cylinder. It contains the chip that stores the passlock code along with the BCM and PCM.

 

So after a couple months of cold mornings and just about every other weather condition, I think I've solved this problem. I replaced my started with a new ACDELCO replacement back in August, and I haven't had any problems since. I made a lot of effort to clean the wire terminals while I was down there too, as they were a little dirty. I'm gonna blame this one on a failing starter, thanks for all the help guys!