ignition won't accept key...
12-27-2014, 03:46 PM
#1
Drifting
Thread Starter
ignition won't accept key...
that's about it... all of a sudden, the key wouldn't go into the ignition without lots of jiggling and swearing. ( Been ok since new...105,000 mi.) I was able to get the key in and turned ONE time, and got a BCM current code, but when I returned to jot down the code, I couldn't get the key to turn the cylinder at all... can't access the codes... any advise?? thanks, dave
12-27-2014, 09:29 PM
#3
Advanced
Not sure exactly what your the problem is. Is it that you cannot turn the key once it is inserted, or that you cannot insert the key at all?
When I bought my car (2004 with about 55,000 miles) I found that about half the time when I inserted the key, I could not turn it. I would then remove it, insert it again, repeat a few times, and finally it would work. I eventually discovered that the key is not symmetric.
My keys (both of the keys that came with the car) are different on the back end. One side is flat while the opposite side has another tooth or two at the very back.
If I insert it with the flat side up, it will not turn. With the flat side down, it works every time. I can only guess that when new, the key can be inserted either way, but over time something wears just enough to not allow it to turn in one orientation.
Hope this helps.
When I bought my car (2004 with about 55,000 miles) I found that about half the time when I inserted the key, I could not turn it. I would then remove it, insert it again, repeat a few times, and finally it would work. I eventually discovered that the key is not symmetric.
My keys (both of the keys that came with the car) are different on the back end. One side is flat while the opposite side has another tooth or two at the very back.
If I insert it with the flat side up, it will not turn. With the flat side down, it works every time. I can only guess that when new, the key can be inserted either way, but over time something wears just enough to not allow it to turn in one orientation.
Hope this helps.
12-28-2014, 09:13 AM
#4
Drifting
Your problem sounds very familiar to the one I had. After shoving the key in the ignition it only went in 1/2 way (I was in a hurry). I was able to get the key out and put it back in after jiggling it a bit but the car would not start. Found out that I damaged the key cylinder and the resistor reader described by 8VETTE7 above. The process he described is exactly what was necessary to fix the problem. As I was out of town and 100 miles away from home I had to have the car towed to a dealer and the dealer replaced the key cylinder after keying it to my car. Not counting rental car, hotel and the towing (happened on a Friday night) the repair was just under $500. If the car is in your garage definitely something to be self performed.
Lesson learned - the key cylinder can be fragile if mistreated.
Lesson learned - the key cylinder can be fragile if mistreated.
12-28-2014, 10:17 AM
#5
Team Owner
I recommend, and use, a quick detachable key ring such that only the ignition key is ever in the lock cylinder. Simple, cheap and effective.
HTH
12-28-2014, 12:37 PM
#6
Drifting
Thread Starter
thanks
I appreciate all the responses... Since I can no longer get the key into the ignition, I figured I'd have to pull the whole switch out and maybe find a locksmith capable of servicing these tumblers. Can the small wire be repaired or replaced? I'd like to (of course) keep the original key as it's easier than having two separate keys. If I get a new tumbler system, can it be set to use the existing key? I'd hoped to avoid the stealership if possible. 
12-28-2014, 12:41 PM
#7
Drifting
Thread Starter
Not sure exactly what your the problem is. Is it that you cannot turn the key once it is inserted, or that you cannot insert the key at all?
When I bought my car (2004 with about 55,000 miles) I found that about half the time when I inserted the key, I could not turn it. I would then remove it, insert it again, repeat a few times, and finally it would work. I eventually discovered that the key is not symmetric.
My keys (both of the keys that came with the car) are different on the back end. One side is flat while the opposite side has another tooth or two at the very back.
If I insert it with the flat side up, it will not turn. With the flat side down, it works every time. I can only guess that when new, the key can be inserted either way, but over time something wears just enough to not allow it to turn in one orientation.
Hope this helps.
When I bought my car (2004 with about 55,000 miles) I found that about half the time when I inserted the key, I could not turn it. I would then remove it, insert it again, repeat a few times, and finally it would work. I eventually discovered that the key is not symmetric.
My keys (both of the keys that came with the car) are different on the back end. One side is flat while the opposite side has another tooth or two at the very back.
If I insert it with the flat side up, it will not turn. With the flat side down, it works every time. I can only guess that when new, the key can be inserted either way, but over time something wears just enough to not allow it to turn in one orientation.
Hope this helps.
Actually I have both these issues. first the key would not go in, then once I got it in, it wouldn't turn....looks like removal time...
12-28-2014, 12:44 PM
#8
Drifting
Thread Starter
With your symptom of an ignition key that will not turn in the ignition cylinder and the fact that you said you had a Current BCM code set, I'll suggest that the code was one (or more) of the following: B2721 or B2722 or B2723.
All 3 codes relate to a problem with the pass key circuit.
I'll also suggest that the security light on the dash did NOT go out the one time you were able to turn the key in the cylinder.
The C5 uses an anti theft system called VATS (Vehicle Anti Theft System). It works like this:
The ignition key has a resistor pellet of a specific value on the key. When you insert the key into the cylinder a fine wire inside the cylinder wipes across the resistor to read the value. The value is sent to the BCM which attempts to match the resistance with a value stored in the computer. If the two values match the Theft Deterrent Relay (TDR) is enabled and the starter receives voltage to crank the engine. If the value is either not read or is read incorrectly the TDR is not enabled and the starter does not receive voltage to crank the engine.
A not uncommon problem on the C5 is that the fine wire in the key cylinder gets damaged or broken off. It will then interfere with the turning of the key in the key cylinder. A worn key, or worn tumblers in the cylinder or lots of "STUFF" hanging from the key chain that contains the C5 key are the most common causes of this problem occurring.
You MAY be able to see the fine piece of wire in the cylinder and with a dental pick be able to remove the piece interfering. But that is only a partial solution because you have nothing to read the resistor on the key so the car will not crank even if you can turn the key (The security light will also remain illuminated.)
There are a couple possible solutions. One is to bypass VATS by putting the right value resistor in the circuit back to the BCM. Here is a table of key resistance values for the C5:
You need to read the resistance value of your key and find it in the chart. You then need to make up a resistor that has a value in the valid range for your key. Radio Shack or other electronic component stores sell precision resistors that you can use to make up the correct value. The resistor has to be placed in the path from the ignition switch back to the BCM. There is a small 2 pin connector that is on the wire going to the lock cylinder. See the picture in the link below:
1997 2004 Chevrolet Corvette Ignition Lock Cylinder | eBay
On the half of the connector that is part of the car wiring, the resistor is connected to those two pins. The cable from the ignition cylinder is left unplugged. The now hard wired resistor fools the BCM into thinking the correct key has been inserted into the lock cylinder.
A major drawback to the VATS bypass is that anyone with a screw driver can steal your car the old fashioned way. Screw driver in the key cylinder and turn it.
Another solution is to replace the key cylinder with a new one. That solution can get to be a lot of fun unless you are willing to have one key to start the car and another to operate the various other lock cylinders on the car. A replacement ignition lock cylinder is available from Ebay or Amazon but they do not come with the tumblers necessary to "code" the cylinder to a key. You pretty much have to go to a dealer to have the cylinder coded. I have been unable to find a place that sells the tumbler kits but you might have better luck.
Hope this helps.
All 3 codes relate to a problem with the pass key circuit.
I'll also suggest that the security light on the dash did NOT go out the one time you were able to turn the key in the cylinder.
The C5 uses an anti theft system called VATS (Vehicle Anti Theft System). It works like this:
The ignition key has a resistor pellet of a specific value on the key. When you insert the key into the cylinder a fine wire inside the cylinder wipes across the resistor to read the value. The value is sent to the BCM which attempts to match the resistance with a value stored in the computer. If the two values match the Theft Deterrent Relay (TDR) is enabled and the starter receives voltage to crank the engine. If the value is either not read or is read incorrectly the TDR is not enabled and the starter does not receive voltage to crank the engine.
A not uncommon problem on the C5 is that the fine wire in the key cylinder gets damaged or broken off. It will then interfere with the turning of the key in the key cylinder. A worn key, or worn tumblers in the cylinder or lots of "STUFF" hanging from the key chain that contains the C5 key are the most common causes of this problem occurring.
You MAY be able to see the fine piece of wire in the cylinder and with a dental pick be able to remove the piece interfering. But that is only a partial solution because you have nothing to read the resistor on the key so the car will not crank even if you can turn the key (The security light will also remain illuminated.)
There are a couple possible solutions. One is to bypass VATS by putting the right value resistor in the circuit back to the BCM. Here is a table of key resistance values for the C5:
You need to read the resistance value of your key and find it in the chart. You then need to make up a resistor that has a value in the valid range for your key. Radio Shack or other electronic component stores sell precision resistors that you can use to make up the correct value. The resistor has to be placed in the path from the ignition switch back to the BCM. There is a small 2 pin connector that is on the wire going to the lock cylinder. See the picture in the link below:
1997 2004 Chevrolet Corvette Ignition Lock Cylinder | eBay
On the half of the connector that is part of the car wiring, the resistor is connected to those two pins. The cable from the ignition cylinder is left unplugged. The now hard wired resistor fools the BCM into thinking the correct key has been inserted into the lock cylinder.
A major drawback to the VATS bypass is that anyone with a screw driver can steal your car the old fashioned way. Screw driver in the key cylinder and turn it.
Another solution is to replace the key cylinder with a new one. That solution can get to be a lot of fun unless you are willing to have one key to start the car and another to operate the various other lock cylinders on the car. A replacement ignition lock cylinder is available from Ebay or Amazon but they do not come with the tumblers necessary to "code" the cylinder to a key. You pretty much have to go to a dealer to have the cylinder coded. I have been unable to find a place that sells the tumbler kits but you might have better luck.
Hope this helps.
12-28-2014, 01:05 PM
#9
Tech Contributor
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Location: Anthony TX
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CI 6,7,8,9,11 Vet
St. Jude Donor '08
There is a broken part inside the lock cylinder. Take the entire ignition switch out and attempt to dislodge the broken/damaged part so you can turn the lock cylinder with the key. Try banging it down on a solid surface and see if it will come out.
Once you can turn the lock cylinder, theres a small SLOT on the side of the ignition switch neck. You can press in on that slot when the ignition key is in the RUN position and the entire key lock cylinder can be removed from the switch neck.
Purchase a new lock cylinder
Once you get that cylinder out, take the new one and the old one to a lock smith
If it were me,, I would also purchase a NEW Ignition Switch!
The lock smith can re-key the new lock cylinder to be able to work with your OEM original key.
Put her all back together in reverse order. You should be good to go. Oh,, the new lock cylinder includes a new key resistor chip reader.
Bill
Once you can turn the lock cylinder, theres a small SLOT on the side of the ignition switch neck. You can press in on that slot when the ignition key is in the RUN position and the entire key lock cylinder can be removed from the switch neck.
Purchase a new lock cylinder
Once you get that cylinder out, take the new one and the old one to a lock smith
If it were me,, I would also purchase a NEW Ignition Switch!
The lock smith can re-key the new lock cylinder to be able to work with your OEM original key.
Put her all back together in reverse order. You should be good to go. Oh,, the new lock cylinder includes a new key resistor chip reader.
Bill
12-28-2014, 04:26 PM
#10
Drifting
Thread Starter
all good advise.. I'll pull the switch this week and report back as to results of attempts to remove whatever is in the tumbler. Many thanks for the input, guys...I had planned on opening the switch and doing the clean and adjust as per Bill's write-up, but I guess at this point, a new switch is probably the best route...Anyone in this section know of a ign. switch-qualified locksmith?? sure would like to keep the orig. key...
Many thanks for the input, guys...I had planned on opening the switch and doing the clean and adjust as per Bill's write-up, but I guess at this point, a new switch is probably the best route...Anyone in this section know of a ign. switch-qualified locksmith?? sure would like to keep the orig. key...
12-28-2014, 05:12 PM
#11
Tech Contributor
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CI 6,7,8,9,11 Vet
St. Jude Donor '08
My buddy John C (he has an 04 C5 coupe), just accomplished this very task and used a Locksmith to re pin the cylinder. I will contact him and see who he used.
OR
You can Gooogle "locksmiths in the XXXX area" and you will get a BIG list. Just call them, ask them if they can re-pin your new cylinder to match the old one. As long as you have your OEM Key, the locksmith can make the new cylinder match it if he has the correct GM Pins.
Bill
OR
You can Gooogle "locksmiths in the XXXX area" and you will get a BIG list. Just call them, ask them if they can re-pin your new cylinder to match the old one. As long as you have your OEM Key, the locksmith can make the new cylinder match it if he has the correct GM Pins.
Bill
Last edited by Bill Curlee; 12-28-2014 at 05:14 PM.