Interior lights stay on, security light continues to flash
08-04-2013, 02:27 AM
#1
Instructor
Thread Starter
Interior lights stay on, security light continues to flash
I also posted this in the C4 technical section so more people can see it:
1991 ZR-1 with the GM add-on keyless entry: Been quite an experience! Went to a car show and the car wouldn't start, but it finally did when the tow truck arrived (no, really) and I got it home, I figure it is the VATS or the ignition key, naturally doesn't happen again, but I plan on getting a few new ignition keys made, install a bypass, or a new ignition lock cylinder. This happened two weeks ago for the first time and I pulled the plenum to gain access to the starter to troubleshoot if the wire to the solenoid had 12 volts, and of course everything worked fine after I tore everything apart... it's hard to troubleshoot an intermittent problem!
So anyway I am doing some troubleshooting, pulling codes, learning about the diagnostics and how the VATS work (have a battery tender on it so I can continue troubleshooting, and now the interior lights stay on and the security light won't stop flashing but the car starts and the security light is now out with the engine running. Don't think it is related to the VATS problem. I switched the interior lights to LED's a while back BTW. The lights will go out after about an hour or so and so will the security light. If I lock the doors with either interior door lock switch, the security light goes solid like it should, but will stay on and also the interior lights.
I am thinking it is the door open plunger switches or door lock key cylinder switches. When I electrically lock the doors using interior door switches the security light goes solid like it should to arm the alarm, I can return it to blinking if I unlock the doors using the door key in the lock cylinders, so I am figuring that those switches are working. By now the doors panels are off, (the wife says I shouldn't have bought a used car BTW when she hears of what is going on) and I remove both door open plunger switches and they both work when I do a continuity test on them with the switches at rest and pushed in, and they do not stick in any way.
I read that if the door lock cylinders sometimes are not straight up and down after the key is removed, that will keep the interior lights on until it times out after an hour or whatever extended period of time, but that is not the case here as I tried that.
After the interior lights go out forever later with both door closed, the security light keeps flashing. HUH? I open the passenger door and now the interior lights are not on but the security light remains on. Open the drivers door and also no interior lights. I slam the either door closed and now the security light is still flashing and the dome lights are on! I am thinking it is the door open plunger switch and even though I tested it good earlier, I again remove the door open plunger switches one at a time and symptoms remain, disconnect the switches and jump the terminals and the same thing happens. I am cursing myself never to buy a GM again wanting to roll a grenade under this car!
I do not think it is the door open plunger switches either and must be something else. What systems effect both the security light staying on with the doors closed and keeping the interior lights on? I am thinking that slamming the door there is some loose connection somewhere. I have the FSM to help me out, but it assumes you do not have the GM keyless entry.
Tomorrow I will try unplugging the keyless entry brain connectors and see if that is screwing up the cars systems. I am at wits end here and can not think of anything else to do. Please help!!!!!
1991 ZR-1 with the GM add-on keyless entry: Been quite an experience! Went to a car show and the car wouldn't start, but it finally did when the tow truck arrived (no, really) and I got it home, I figure it is the VATS or the ignition key, naturally doesn't happen again, but I plan on getting a few new ignition keys made, install a bypass, or a new ignition lock cylinder. This happened two weeks ago for the first time and I pulled the plenum to gain access to the starter to troubleshoot if the wire to the solenoid had 12 volts, and of course everything worked fine after I tore everything apart... it's hard to troubleshoot an intermittent problem!
So anyway I am doing some troubleshooting, pulling codes, learning about the diagnostics and how the VATS work (have a battery tender on it so I can continue troubleshooting, and now the interior lights stay on and the security light won't stop flashing but the car starts and the security light is now out with the engine running. Don't think it is related to the VATS problem. I switched the interior lights to LED's a while back BTW. The lights will go out after about an hour or so and so will the security light. If I lock the doors with either interior door lock switch, the security light goes solid like it should, but will stay on and also the interior lights.
I am thinking it is the door open plunger switches or door lock key cylinder switches. When I electrically lock the doors using interior door switches the security light goes solid like it should to arm the alarm, I can return it to blinking if I unlock the doors using the door key in the lock cylinders, so I am figuring that those switches are working. By now the doors panels are off, (the wife says I shouldn't have bought a used car BTW when she hears of what is going on) and I remove both door open plunger switches and they both work when I do a continuity test on them with the switches at rest and pushed in, and they do not stick in any way.
I read that if the door lock cylinders sometimes are not straight up and down after the key is removed, that will keep the interior lights on until it times out after an hour or whatever extended period of time, but that is not the case here as I tried that.
After the interior lights go out forever later with both door closed, the security light keeps flashing. HUH? I open the passenger door and now the interior lights are not on but the security light remains on. Open the drivers door and also no interior lights. I slam the either door closed and now the security light is still flashing and the dome lights are on! I am thinking it is the door open plunger switch and even though I tested it good earlier, I again remove the door open plunger switches one at a time and symptoms remain, disconnect the switches and jump the terminals and the same thing happens. I am cursing myself never to buy a GM again wanting to roll a grenade under this car!
I do not think it is the door open plunger switches either and must be something else. What systems effect both the security light staying on with the doors closed and keeping the interior lights on? I am thinking that slamming the door there is some loose connection somewhere. I have the FSM to help me out, but it assumes you do not have the GM keyless entry.
Tomorrow I will try unplugging the keyless entry brain connectors and see if that is screwing up the cars systems. I am at wits end here and can not think of anything else to do. Please help!!!!!
Last edited by blownrunner; 08-04-2013 at 02:32 AM.
08-04-2013, 09:47 AM
#2
OK my 2 cents from my experience. 2 other things that will happen when the car thinks the door plunger is not open(ie the car doesn't get the signal that the door has been opened) 1) the radio will stay on for 15 minutes and 2) the center console hatch popper switch won't work.- in addition to what you observed.
Another thing to look for is if you are driving around, go over bumps that "flex" the car and the interior lights flicker,,,this indicates that the switch is in together but the plunger might need to be adjusted.
in my case the switch was blown apart in 2 pieces and the car thought the door was never opened.
And they can get dirty and the plunger can stick before it fully opens. WD works great for this
try this; open the door, try to depress the plunger all of the way in and see if the systems work and then try and observe if the plunger comes all of the way OUT. you would be surprised how little it needs to move at the end of its travel to actually "work".
hope this helps
Another thing to look for is if you are driving around, go over bumps that "flex" the car and the interior lights flicker,,,this indicates that the switch is in together but the plunger might need to be adjusted.
in my case the switch was blown apart in 2 pieces and the car thought the door was never opened.
And they can get dirty and the plunger can stick before it fully opens. WD works great for this
try this; open the door, try to depress the plunger all of the way in and see if the systems work and then try and observe if the plunger comes all of the way OUT. you would be surprised how little it needs to move at the end of its travel to actually "work".
hope this helps
08-04-2013, 12:30 PM
#3
Instructor
Thread Starter
I slept on it and I think I figured it out this AM. Playing with the keyless entry and disconnecting it didn't work, actually the unit acted weird when I tried to arm the alarm/lock the doors. I went in the diagnostics of the CCM, no codes, then went into the CCM where it tell you what signals it is receiving from what sensors. It turns out that BOTH the door open plunger switches are bad simultaneously! If they are pushed in manually, the CCM sees them as the door is closed, when the doors are actually closed, the plunger doesn't make contact. So naturally when I troubleshoot the interior lights and the security light to by playing with one door switch, I was assuming the other door switch was working. The CCM was actually being told that both doors were opened. Once again, I figured this out reading what the CCM inputs were in the diagnostic mode. The best part of this is that the service manual's troubleshooting tree actually tells you to disconnect the light switch, then it goes on to having you pull the center dash apart to get access to the CCM and it's gray harness plug, the latter which I didn't have to do, thank the heavens. I checked the other CCM inputs and the CCM was getting the correct information from the switches. How can both switches stop working correctly in a four hour period?! I am increasingly amazed how confusingly something can fail taking tools like common sense and troubleshooting trees and throwing them out a window!
So while at this point it still isn't fixed, at least I think I know what is wrong. While I was badmouthing the car yesterday, the diagnostic system for the CCM in actuality is a really nice feature and had I been in the know in the first place and not followed the troubleshooting tree and my common sense, I could have figured this out in 20 minutes.
So while at this point it still isn't fixed, at least I think I know what is wrong. While I was badmouthing the car yesterday, the diagnostic system for the CCM in actuality is a really nice feature and had I been in the know in the first place and not followed the troubleshooting tree and my common sense, I could have figured this out in 20 minutes.
Last edited by blownrunner; 08-04-2013 at 12:36 PM.
