Security light and NO START!!
Le Mans Master
Joined: Oct 2000
Posts: 6,362
Likes: 30
From: Oak Harbor WA
Took console all apart and have removed the ignition swith again. Took switch all apart and put it back together again too. Contacts were fine and not all that burnt up, cleaned off easily with a pencil eraser. I'm certain that has nothing to do with this issue. It is the wiring from the switch to the BCM I'm bettin' on.
Got the code B2721 without the PCM code that usually accompanies it (P1631) last night while testing and got 12.1 volts at the TDR (big red wire). I can't help but think it is the little PASS-Key circuit that is giving me fits. Might just try the resistor bypass solution yet just to see.
Also, if you remove the ignition switch without unhooking the battery first the interior door chime gets a bit incessant, so unhook battery first.
Got the code B2721 without the PCM code that usually accompanies it (P1631) last night while testing and got 12.1 volts at the TDR (big red wire). I can't help but think it is the little PASS-Key circuit that is giving me fits. Might just try the resistor bypass solution yet just to see.
Also, if you remove the ignition switch without unhooking the battery first the interior door chime gets a bit incessant, so unhook battery first.
Thread Starter
Pro
Joined: Nov 2005
Posts: 656
Likes: 5
From: McAlester Oklahoma
Hey Goody, it does sound like we are experiancing the same thing. I didnt have a whole lot of time over the last week to mess with it as we had some concrete poured so I had to leave the vette in the garage for about a week. One thing I did do was to unplug the inline relay and check for corosion. Sure enough, there was some. I sprayed contact cleaner into the contacts in the plug and cleaned off the relay pins. Didnt clean them real good as I was pressed for time. Side note on the plug, it looks to have at one time been attached to a peice of plastic. Well, it is broken off and just hangs there now. I didnt break it, but it has been broken. I am wondering with it broke if it is just banging something in there when I hit a peice of rough road? I wonder if this causes the relay to malfunction? Could a new relay and securing the plug solve my problem? I dont know, but I am about to try it. I did drive to work this morning and the light didnt come on when I hit the rough spot in the road. I am still not convinced though....
Tech Contributor
Joined: Jan 2007
Posts: 19,398
Likes: 1,139
From: Dyer, IN
Took console all apart and have removed the ignition swith again. Took switch all apart and put it back together again too. Contacts were fine and not all that burnt up, cleaned off easily with a pencil eraser. I'm certain that has nothing to do with this issue. It is the wiring from the switch to the BCM I'm bettin' on.
Got the code B2721 without the PCM code that usually accompanies it (P1631) last night while testing and got 12.1 volts at the TDR (big red wire). I can't help but think it is the little PASS-Key circuit that is giving me fits. Might just try the resistor bypass solution yet just to see.
Also, if you remove the ignition switch without unhooking the battery first the interior door chime gets a bit incessant, so unhook battery first.
Got the code B2721 without the PCM code that usually accompanies it (P1631) last night while testing and got 12.1 volts at the TDR (big red wire). I can't help but think it is the little PASS-Key circuit that is giving me fits. Might just try the resistor bypass solution yet just to see.
Also, if you remove the ignition switch without unhooking the battery first the interior door chime gets a bit incessant, so unhook battery first.
Le Mans Master
Joined: Oct 2000
Posts: 6,362
Likes: 30
From: Oak Harbor WA
Not sure why you check that wire during the test(other than confirming 12 volts) as it is hot at all times. The wire you need to check, while doing a start test, is the yellow wire. Looking at the internal contacts of the ignition switch is fine, but those are for routing voltage, not pass key detection/reading.
I'll do the yellow wire test today when I get home. Wasn't real sure about that one to be honest. I have a thread for my issue as well asking for help trying to figure this out. Automotive electrical systems are a weakness for me.
Yeah I realize the switch has nothing to do with the pass key system since the wiring from the lock cylinder doesn't go through the switch harness at all..... okay so I did learn something and figure it out afterall.
Le Mans Master
Joined: Oct 2000
Posts: 6,362
Likes: 30
From: Oak Harbor WA
Battery has been hooked to the C-TEK for two full days.
So, I hook up my DMM (set to 200VDC) to the car (red lead to the yellow wire on the TDR) and clip the black ground to a grounded location near the doors ground (G202). Go to start the car the very first time and get 12.5 volts and no activity. Figure oh great here we go, time to get some good (or bad data really) research done. As soon as I let the key go the voltage drops back to the near zero setting (which is expected).
Second attempt to start car and varoom.....unable to get a no start again for 10 more tries. Damn car starts every time. So things are back to normal again. Have the code B2721 in History so I cleared it. I have stopped for now because I don't like abusing my starter that much.
Going back out now to double check the accordian section of my doors just to be sure nothing has changed.
Thread Starter
Pro
Joined: Nov 2005
Posts: 656
Likes: 5
From: McAlester Oklahoma
I just need help checking wires, knowing what to check and where to "touch" to get the reading. Again, I am lost when it comes to electronics. So what your saying is in order to diagnose the yellow wire, does the light need to come on to get a reading? What if the light is on, can you just leave the car running and check the yellow wire? I am so confused about it. I will have time to check it this weekend, but I need to know exactly what to do! LOL!!
On my drive home yesterday the light came back on. No bumps or anything like that. Was just on a smooth road and it popped up. Ugh....
On my drive home yesterday the light came back on. No bumps or anything like that. Was just on a smooth road and it popped up. Ugh....
Tech Contributor
Joined: Jan 2007
Posts: 19,398
Likes: 1,139
From: Dyer, IN
I just need help checking wires, knowing what to check and where to "touch" to get the reading. Again, I am lost when it comes to electronics. So what your saying is in order to diagnose the yellow wire, does the light need to come on to get a reading? What if the light is on, can you just leave the car running and check the yellow wire? I am so confused about it. I will have time to check it this weekend, but I need to know exactly what to do! LOL!!
On my drive home yesterday the light came back on. No bumps or anything like that. Was just on a smooth road and it popped up. Ugh....
On my drive home yesterday the light came back on. No bumps or anything like that. Was just on a smooth road and it popped up. Ugh....
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Thread Starter
Pro
Joined: Nov 2005
Posts: 656
Likes: 5
From: McAlester Oklahoma
Ignition switch?? Lucky, I value your knowledge greatly, but I thought for sure that mine would not be the ignition switch. I am confused now...LOL!!! Think I could do a cleaning on it and that might fix it or do you think it is something cleaning wouldnt corrrect?
Tech Contributor
Joined: Jan 2007
Posts: 19,398
Likes: 1,139
From: Dyer, IN
Thread Starter
Pro
Joined: Nov 2005
Posts: 656
Likes: 5
From: McAlester Oklahoma
LOL!!! No problem man! So here is where I am at:
Replaced Ignition Lock Cylinder and still get the Security Light. I did not change the ignition switch, nor have I cleaned it.
It seems to come on going over bumps, but noticed yesterday that on a smooth road it popped on. Havent seen it come on right when I start it since the new lock cylinder.
Time to check wires?
Replaced Ignition Lock Cylinder and still get the Security Light. I did not change the ignition switch, nor have I cleaned it.
It seems to come on going over bumps, but noticed yesterday that on a smooth road it popped on. Havent seen it come on right when I start it since the new lock cylinder.
Time to check wires?
Tech Contributor
Joined: Jan 2007
Posts: 19,398
Likes: 1,139
From: Dyer, IN
LOL!!! No problem man! So here is where I am at:
Replaced Ignition Lock Cylinder and still get the Security Light. I did not change the ignition switch, nor have I cleaned it.
It seems to come on going over bumps, but noticed yesterday that on a smooth road it popped on. Havent seen it come on right when I start it since the new lock cylinder.
Time to check wires?
Replaced Ignition Lock Cylinder and still get the Security Light. I did not change the ignition switch, nor have I cleaned it.
It seems to come on going over bumps, but noticed yesterday that on a smooth road it popped on. Havent seen it come on right when I start it since the new lock cylinder.
Time to check wires?
1) BCM problem
2) Wiring between the lock cylinder and the BCM
3) Bad key
Thread Starter
Pro
Joined: Nov 2005
Posts: 656
Likes: 5
From: McAlester Oklahoma
BCM Problem: Does this mean a dealership or mechanic needs to look at it?
Wiring between the lock cylinder and the BCM: Something I can check with multi meter?
Bad Key: I have thought about replacing them both. May go ahead and do that.
Wiring between the lock cylinder and the BCM: Something I can check with multi meter?
Bad Key: I have thought about replacing them both. May go ahead and do that.
Tech Contributor
Joined: Jan 2007
Posts: 19,398
Likes: 1,139
From: Dyer, IN
Pretty unlikely that both keys would be bad though. Doing a resistor bypass would be helpful troubleshooting, should the wiring prove good.
Thread Starter
Pro
Joined: Nov 2005
Posts: 656
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From: McAlester Oklahoma
Looks like it is wires this weekend. I will do what Goody did and check the yellow wire as I am trying to start it. Is that correct?
As far as the BCM, i will open the cover just to make sure there isnt any corrosion or anything that could be causing it.
One question for you, the inline relay on the TDR, could that relay be bad?
As far as the BCM, i will open the cover just to make sure there isnt any corrosion or anything that could be causing it.
One question for you, the inline relay on the TDR, could that relay be bad?
Tech Contributor
Joined: Jan 2007
Posts: 19,398
Likes: 1,139
From: Dyer, IN
Again, the TDR is working. You have a security light that comes on after the car has started, which indicates that there is a problem with the key resistance being read by the BCM. The B2721 code supports this.
Tech Contributor
Joined: Jan 2007
Posts: 19,398
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From: Dyer, IN
. I listed three possibilities in post #32. The reality is, the wiring is the most likely issue, given that BOTH keys having the same issue is possible, but not probable. That's why I suggested the resistor bypass if the wiring checks good. The wiring between the lock cylinder and the BCM......and the wiring through the TDR.....are two different circuits. The Pass Key detection is an INPUT to the BCM, while the TDR being enabled is an OUTPUT from the BCM.
Thread Starter
Pro
Joined: Nov 2005
Posts: 656
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From: McAlester Oklahoma
Ok, so it boils down to me checking the wiring and go from there. Ok, thats the plan this weekend hopefully. Thanks for the help Lucky. I know I am not the easiest person to explain things to, but you have really helped. Once I am able to check the wiring, i will post the results.
Le Mans Master
Joined: Oct 2000
Posts: 6,362
Likes: 30
From: Oak Harbor WA
Update on my testing
Hey Kennya35,
I did some additional testing last night when I got home. Hoped in the car and tried to start it. Nothing, nadda....no internal lights, no guage sweep or anything. This was completely new and unexpected. So I then put the DVM on the TDR again and when I tried to start the car I did see the 12.4v while in the Start position. So as Lucky has pointed out I can now eliminate the TDR and fuse from the equation. After a couple more tries the internal lights came on and the car did the sweep as expected.
I tried the clutch pedal up and down thing a few times with the key in Start position and it made no difference.
I shook the key and did a few in and outs with the key. No change.
Before the three minutes would elapse though (the book says that if you try to start the car before the three minutes elapses the clock resets) I yanked on the ignition switch harness connectors and then when I turned the key the car started right up!!!
It is either a wire harness at the switch or the switch itself....at least in my case.
My new parts come in next week.
I did some additional testing last night when I got home. Hoped in the car and tried to start it. Nothing, nadda....no internal lights, no guage sweep or anything. This was completely new and unexpected. So I then put the DVM on the TDR again and when I tried to start the car I did see the 12.4v while in the Start position. So as Lucky has pointed out I can now eliminate the TDR and fuse from the equation. After a couple more tries the internal lights came on and the car did the sweep as expected.
I tried the clutch pedal up and down thing a few times with the key in Start position and it made no difference.
I shook the key and did a few in and outs with the key. No change.
Before the three minutes would elapse though (the book says that if you try to start the car before the three minutes elapses the clock resets) I yanked on the ignition switch harness connectors and then when I turned the key the car started right up!!!
It is either a wire harness at the switch or the switch itself....at least in my case.
My new parts come in next week.