Passive Keyless Entry problem - '95 coupe, 6 spd
10-02-2008, 01:22 PM
#1
Pro
Thread Starter
Passive Keyless Entry problem - '95 coupe, 6 spd
Here's one that has me scratching my head ...
History:
0. I don't use the remotes. They are left in the house, although I never disabled the PKE system. During all this time, the PKE light has come on (at start up) to indicate that the system is active, just as the owner's manual and service manual say it should.
1. Once (more than a year ago) my wife and I were out cruising around, and I made a high speed pass. As I was returning to my lane, the PKE warning light in the Driver Information Center turned on briefly, then turned off.
2. September 2007, as we were driving to Bowling Green, at steady speed (70 MPH, cruise NOT engaged), the interior lights came on, the power door locks cycled (locked, then unlocked), and then the rear hatch released and the hatch opened. The PKE light came on, and then went off. Annie closed the hatch (after I stopped), and no other problems occurred for the remainder of our trip. In fact, no other issues occurred for the rest of the 2007 driving season.
3. Late Spring 2008, I started the car to take my daughter to a class, and the PKE light came on, and stayed on. When I got back home, I shut down the engine, removed the key, and upon a restart, the PKE light went out.
4. Last week, I got in the car to run an errand, and the PKE light came on. I shut down, restarted, and the light went out. However, as I drove to my first stop, the PKE light came back on, and the door locks attempted to cycle (the lock solenoid emitted a rattle, and the door remained unlocked). Again, the PKE light went out. I parked the car (and locked it) to run errand #1. As I approached the car, the hatch popped open (keep in mind that I DON'T have the remote with me!). The doors remained locked, and I used my key (as usual) to unlock the driver side door. The PKE light didn't light after the car was started, and when I tried the power door lock switch, the doors locked normally. I took the car home, since my next errand was going to involve a couple of hours away from the car, and I didn't want to come back to an open hatch.
5. I had occasion to move the car out of the garage, and left it unlocked. When I attempted to enter the car about 20 minutes later, the doors were locked.
6. The car mostly sat since last week, but I took a short drive (~ 40 minutes) yesterday. I noticed that the doors were locked when I tried to open the door. No light came on, and the car behaved normally through two additonal start cycles.
7. I opened the garage tonight, and the hatch was open again, and the doors were locked.
I put the key in the run position, and noticed that the PKE light did NOT light, which would indicate that the PKE system has been disabled (although I didn't do it - I swear!). So, I took the PKE fob out to the car, and it doesn't react to it at all. I suspect that the remote battery may be dead, so I'm not real surprised by that.
My next step is to replace the remote battery, and see if I can get the PKE system to recognize it.
My biggest concern is why the hatch is opening. As far as I can tell from the circuit diagram, there are only three ways to open the hatch with the engine OFF:
1. the PKE can supply a ground path to the hatch solenoid
2. with the door open, use the hatch release switch on the door to supply the ground
3. the center console button can provide a ground to the hatch solenoid
Since the PKE system appears to have lost its mind, I'm suspecting that the PKE module is the culprit.
So, here's a question: If I pull the PKE fuse on the fuse panel, will that disable anything other than the PKE system? Will the power door locks or the hatch release (door or console - I dont care about the remote) be disabled if the PKE module isn't operational? The circuit diagram leads me to think that the PKE won't disable the other methods, but I'm not certain at this point.
Any ideas or suggestions would be greatly appreciated!
Thanks,
Steven
History:
0. I don't use the remotes. They are left in the house, although I never disabled the PKE system. During all this time, the PKE light has come on (at start up) to indicate that the system is active, just as the owner's manual and service manual say it should.
1. Once (more than a year ago) my wife and I were out cruising around, and I made a high speed pass. As I was returning to my lane, the PKE warning light in the Driver Information Center turned on briefly, then turned off.
2. September 2007, as we were driving to Bowling Green, at steady speed (70 MPH, cruise NOT engaged), the interior lights came on, the power door locks cycled (locked, then unlocked), and then the rear hatch released and the hatch opened. The PKE light came on, and then went off. Annie closed the hatch (after I stopped), and no other problems occurred for the remainder of our trip. In fact, no other issues occurred for the rest of the 2007 driving season.
3. Late Spring 2008, I started the car to take my daughter to a class, and the PKE light came on, and stayed on. When I got back home, I shut down the engine, removed the key, and upon a restart, the PKE light went out.
4. Last week, I got in the car to run an errand, and the PKE light came on. I shut down, restarted, and the light went out. However, as I drove to my first stop, the PKE light came back on, and the door locks attempted to cycle (the lock solenoid emitted a rattle, and the door remained unlocked). Again, the PKE light went out. I parked the car (and locked it) to run errand #1. As I approached the car, the hatch popped open (keep in mind that I DON'T have the remote with me!). The doors remained locked, and I used my key (as usual) to unlock the driver side door. The PKE light didn't light after the car was started, and when I tried the power door lock switch, the doors locked normally. I took the car home, since my next errand was going to involve a couple of hours away from the car, and I didn't want to come back to an open hatch.
5. I had occasion to move the car out of the garage, and left it unlocked. When I attempted to enter the car about 20 minutes later, the doors were locked.
6. The car mostly sat since last week, but I took a short drive (~ 40 minutes) yesterday. I noticed that the doors were locked when I tried to open the door. No light came on, and the car behaved normally through two additonal start cycles.
7. I opened the garage tonight, and the hatch was open again, and the doors were locked.
I put the key in the run position, and noticed that the PKE light did NOT light, which would indicate that the PKE system has been disabled (although I didn't do it - I swear!). So, I took the PKE fob out to the car, and it doesn't react to it at all. I suspect that the remote battery may be dead, so I'm not real surprised by that.
My next step is to replace the remote battery, and see if I can get the PKE system to recognize it.
My biggest concern is why the hatch is opening. As far as I can tell from the circuit diagram, there are only three ways to open the hatch with the engine OFF:
1. the PKE can supply a ground path to the hatch solenoid
2. with the door open, use the hatch release switch on the door to supply the ground
3. the center console button can provide a ground to the hatch solenoid
Since the PKE system appears to have lost its mind, I'm suspecting that the PKE module is the culprit.
So, here's a question: If I pull the PKE fuse on the fuse panel, will that disable anything other than the PKE system? Will the power door locks or the hatch release (door or console - I dont care about the remote) be disabled if the PKE module isn't operational? The circuit diagram leads me to think that the PKE won't disable the other methods, but I'm not certain at this point.
Any ideas or suggestions would be greatly appreciated!
Thanks,
Steven
10-03-2008, 09:05 PM
#5
Something similar happened to my 96 - once.
I never had the keyless thingy. The car had 100k miles when I acquired it. No idea what became of it.
The power doorlocks worked and no unusual lights came on at first. Out driving and hit a nasty pothole. PKE light comes on.
Since then the light comes on after a while. Restarting kills it temporarily. I found the car once with the hatch up and the doors locked. Put it down to a particularly obnoxious little girl fooling around. Started locking the car and it didn't happen again. After reading the above I now wonder.
Car sat for a year and a half. Got it out. The light now comes on almost immediately and the power doorlocks are dead. And that's where we are at this time.
I never had the keyless thingy. The car had 100k miles when I acquired it. No idea what became of it.
The power doorlocks worked and no unusual lights came on at first. Out driving and hit a nasty pothole. PKE light comes on.
Since then the light comes on after a while. Restarting kills it temporarily. I found the car once with the hatch up and the doors locked. Put it down to a particularly obnoxious little girl fooling around. Started locking the car and it didn't happen again. After reading the above I now wonder.
Car sat for a year and a half. Got it out. The light now comes on almost immediately and the power doorlocks are dead. And that's where we are at this time.
10-03-2008, 09:18 PM
#6
Melting Slicks
Here's one that has me scratching my head ...
History:
0. I don't use the remotes. They are left in the house, although I never disabled the PKE system. During all this time, the PKE light has come on (at start up) to indicate that the system is active, just as the owner's manual and service manual say it should.
1. Once (more than a year ago) my wife and I were out cruising around, and I made a high speed pass. As I was returning to my lane, the PKE warning light in the Driver Information Center turned on briefly, then turned off.
2. September 2007, as we were driving to Bowling Green, at steady speed (70 MPH, cruise NOT engaged), the interior lights came on, the power door locks cycled (locked, then unlocked), and then the rear hatch released and the hatch opened. The PKE light came on, and then went off. Annie closed the hatch (after I stopped), and no other problems occurred for the remainder of our trip. In fact, no other issues occurred for the rest of the 2007 driving season.
3. Late Spring 2008, I started the car to take my daughter to a class, and the PKE light came on, and stayed on. When I got back home, I shut down the engine, removed the key, and upon a restart, the PKE light went out.
4. Last week, I got in the car to run an errand, and the PKE light came on. I shut down, restarted, and the light went out. However, as I drove to my first stop, the PKE light came back on, and the door locks attempted to cycle (the lock solenoid emitted a rattle, and the door remained unlocked). Again, the PKE light went out. I parked the car (and locked it) to run errand #1. As I approached the car, the hatch popped open (keep in mind that I DON'T have the remote with me!). The doors remained locked, and I used my key (as usual) to unlock the driver side door. The PKE light didn't light after the car was started, and when I tried the power door lock switch, the doors locked normally. I took the car home, since my next errand was going to involve a couple of hours away from the car, and I didn't want to come back to an open hatch.
5. I had occasion to move the car out of the garage, and left it unlocked. When I attempted to enter the car about 20 minutes later, the doors were locked.
6. The car mostly sat since last week, but I took a short drive (~ 40 minutes) yesterday. I noticed that the doors were locked when I tried to open the door. No light came on, and the car behaved normally through two additonal start cycles.
7. I opened the garage tonight, and the hatch was open again, and the doors were locked.
I put the key in the run position, and noticed that the PKE light did NOT light, which would indicate that the PKE system has been disabled (although I didn't do it - I swear!). So, I took the PKE fob out to the car, and it doesn't react to it at all. I suspect that the remote battery may be dead, so I'm not real surprised by that.
My next step is to replace the remote battery, and see if I can get the PKE system to recognize it.
My biggest concern is why the hatch is opening. As far as I can tell from the circuit diagram, there are only three ways to open the hatch with the engine OFF:
1. the PKE can supply a ground path to the hatch solenoid
2. with the door open, use the hatch release switch on the door to supply the ground
3. the center console button can provide a ground to the hatch solenoid
Since the PKE system appears to have lost its mind, I'm suspecting that the PKE module is the culprit.
So, here's a question: If I pull the PKE fuse on the fuse panel, will that disable anything other than the PKE system? Will the power door locks or the hatch release (door or console - I dont care about the remote) be disabled if the PKE module isn't operational? The circuit diagram leads me to think that the PKE won't disable the other methods, but I'm not certain at this point.
Any ideas or suggestions would be greatly appreciated!
Thanks,
Steven
History:
0. I don't use the remotes. They are left in the house, although I never disabled the PKE system. During all this time, the PKE light has come on (at start up) to indicate that the system is active, just as the owner's manual and service manual say it should.
1. Once (more than a year ago) my wife and I were out cruising around, and I made a high speed pass. As I was returning to my lane, the PKE warning light in the Driver Information Center turned on briefly, then turned off.
2. September 2007, as we were driving to Bowling Green, at steady speed (70 MPH, cruise NOT engaged), the interior lights came on, the power door locks cycled (locked, then unlocked), and then the rear hatch released and the hatch opened. The PKE light came on, and then went off. Annie closed the hatch (after I stopped), and no other problems occurred for the remainder of our trip. In fact, no other issues occurred for the rest of the 2007 driving season.
3. Late Spring 2008, I started the car to take my daughter to a class, and the PKE light came on, and stayed on. When I got back home, I shut down the engine, removed the key, and upon a restart, the PKE light went out.
4. Last week, I got in the car to run an errand, and the PKE light came on. I shut down, restarted, and the light went out. However, as I drove to my first stop, the PKE light came back on, and the door locks attempted to cycle (the lock solenoid emitted a rattle, and the door remained unlocked). Again, the PKE light went out. I parked the car (and locked it) to run errand #1. As I approached the car, the hatch popped open (keep in mind that I DON'T have the remote with me!). The doors remained locked, and I used my key (as usual) to unlock the driver side door. The PKE light didn't light after the car was started, and when I tried the power door lock switch, the doors locked normally. I took the car home, since my next errand was going to involve a couple of hours away from the car, and I didn't want to come back to an open hatch.
5. I had occasion to move the car out of the garage, and left it unlocked. When I attempted to enter the car about 20 minutes later, the doors were locked.
6. The car mostly sat since last week, but I took a short drive (~ 40 minutes) yesterday. I noticed that the doors were locked when I tried to open the door. No light came on, and the car behaved normally through two additonal start cycles.
7. I opened the garage tonight, and the hatch was open again, and the doors were locked.
I put the key in the run position, and noticed that the PKE light did NOT light, which would indicate that the PKE system has been disabled (although I didn't do it - I swear!). So, I took the PKE fob out to the car, and it doesn't react to it at all. I suspect that the remote battery may be dead, so I'm not real surprised by that.
My next step is to replace the remote battery, and see if I can get the PKE system to recognize it.
My biggest concern is why the hatch is opening. As far as I can tell from the circuit diagram, there are only three ways to open the hatch with the engine OFF:
1. the PKE can supply a ground path to the hatch solenoid
2. with the door open, use the hatch release switch on the door to supply the ground
3. the center console button can provide a ground to the hatch solenoid
Since the PKE system appears to have lost its mind, I'm suspecting that the PKE module is the culprit.
So, here's a question: If I pull the PKE fuse on the fuse panel, will that disable anything other than the PKE system? Will the power door locks or the hatch release (door or console - I dont care about the remote) be disabled if the PKE module isn't operational? The circuit diagram leads me to think that the PKE won't disable the other methods, but I'm not certain at this point.
Any ideas or suggestions would be greatly appreciated!
Thanks,
Steven
No 3 is # 42 which is for the power locks & also integrated with the PKE module.
A little confusing isn't it? Have you checked the door ajar switches for proper function?
This from the FSM for 95.
10-03-2008, 11:38 PM
#7
Pro
Thread Starter
Thanks for the reply, Red Dwarf! I have some answers to your question about the door switches, with an update.
Today's update ...
Yesterday, I lubricated the plunger mechanisms on both door switches, although they have good action.
I also pulled the PKE fuse.
I would have set the PKE system to disable, but the PKE system has apparently already disabled itself - the other day (before I removed the fuse), the light stopped coming on when the key is inserted and the ignition is set to run. Additionally, the PKE system won't respond to the commands of either key fob that I own. However, I haven't tried setting the "recognize new fob" at this point.
I took the car to work today - when I went to the garage this morning, the hatch was secure, but the doors were locked.
At the end of the work day, the car was apparently in the state I'd left it - the hatch was closed, and the doors were locked.
There was some bird poop on the hood, so when I got home, I got out of the car (left it unlocked, since it is in the garage), and proceeded to clean off the bird poop. When I finished that little exercise, I was getting ready to throw away the towel, when the doors locked and the hatch popped open! Additionally, the PKE light was lit on the dash, and stayed lit while I closed the hatch, unlocked the drivers door, and finally put the key in and cycled the ignition to run.
We had some errands to run tonight, so I left the car unlocked, and we left. When I got home a few minutes ago, the doors were locked and the hatch was closed. I unlocked the doors, hoping that it would do the same thing again (lock the doors, release the hatch) - I really want to get this to a repeatable state so I can properly troubleshoot it. Well, I heard the sound of a relay, a very soft horn beep, but no lock cycle. However, when the horn sounded, the interior lights came on (and then went out normally). The PKE light was NOT set, and the doors remained unlocked. So, I thought I would just lock the car and see if the hatch stayed down overnight. When I opened the UNLOCKED door, the alarm system went off (it stopped when I inserted the key and cycled the ignition).
The doors are now locked, the hatch is down, and we'll see what happens overnight.
Questions ...
What does the fuse do? I'm certain that I pulled the PKE fuse!
What made the alarm set, and why didn't it set properly (ie, lock the doors and sound a solid horn beep)?
Does all this relate to a failure of the PKE module? Are they still available from GM? Is there a market for used ones? Would you trust a used one?
Steven
Today's update ...
Yesterday, I lubricated the plunger mechanisms on both door switches, although they have good action.
I also pulled the PKE fuse.
I would have set the PKE system to disable, but the PKE system has apparently already disabled itself - the other day (before I removed the fuse), the light stopped coming on when the key is inserted and the ignition is set to run. Additionally, the PKE system won't respond to the commands of either key fob that I own. However, I haven't tried setting the "recognize new fob" at this point.
I took the car to work today - when I went to the garage this morning, the hatch was secure, but the doors were locked.
At the end of the work day, the car was apparently in the state I'd left it - the hatch was closed, and the doors were locked.
There was some bird poop on the hood, so when I got home, I got out of the car (left it unlocked, since it is in the garage), and proceeded to clean off the bird poop. When I finished that little exercise, I was getting ready to throw away the towel, when the doors locked and the hatch popped open! Additionally, the PKE light was lit on the dash, and stayed lit while I closed the hatch, unlocked the drivers door, and finally put the key in and cycled the ignition to run.
We had some errands to run tonight, so I left the car unlocked, and we left. When I got home a few minutes ago, the doors were locked and the hatch was closed. I unlocked the doors, hoping that it would do the same thing again (lock the doors, release the hatch) - I really want to get this to a repeatable state so I can properly troubleshoot it. Well, I heard the sound of a relay, a very soft horn beep, but no lock cycle. However, when the horn sounded, the interior lights came on (and then went out normally). The PKE light was NOT set, and the doors remained unlocked. So, I thought I would just lock the car and see if the hatch stayed down overnight. When I opened the UNLOCKED door, the alarm system went off (it stopped when I inserted the key and cycled the ignition).
The doors are now locked, the hatch is down, and we'll see what happens overnight.
Questions ...
What does the fuse do? I'm certain that I pulled the PKE fuse!
What made the alarm set, and why didn't it set properly (ie, lock the doors and sound a solid horn beep)?
Does all this relate to a failure of the PKE module? Are they still available from GM? Is there a market for used ones? Would you trust a used one?
Steven
10-04-2008, 05:00 PM
#8
Drifting
Member Since: Sep 2003
Location: 1994 LT1 Coupe 6-speed with FX3 & 2000 LS1 Vert 6-Speed with F45 Hunterdon County, NJ
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replace BOTH door switches
my vote would be the door switches (courtesy light).
They can fail in 3 ways --
mechanically -- sticking so they don't move out (to close the circuit) or their 'nose' is pushed in too far so that when the door is closed, they do not push in far enough to 'open' the circuit.
Electrically -- either they no longer 'close' the circuit, or do so intermittenly -- possibly due to water intrusion, or they never 'open' the circuit again probably due to water/rust.
The relationship of the door switches to the hatch popping does exist (although walking you through the electrical diagrams would take too long to explain), and happened to our 94 before I replaced both door switches (which can be done through their hole and do not require taking the door apart).
Rember there is a way of putting the CCM into a test mode so that you can 'test' many things, including the door switches -- see your FSM.
Lastly, when buying, carefully examine the switches (from dealer or NAPA). I got 3 sets of 'bad' switches from the dealer (mechanical, poor glueing or electrical issues) before getting good ones. ALso, only use vaseline to lube, other chemicals expand the plastic and cause them to stick.
They can fail in 3 ways --
mechanically -- sticking so they don't move out (to close the circuit) or their 'nose' is pushed in too far so that when the door is closed, they do not push in far enough to 'open' the circuit.
Electrically -- either they no longer 'close' the circuit, or do so intermittenly -- possibly due to water intrusion, or they never 'open' the circuit again probably due to water/rust.
The relationship of the door switches to the hatch popping does exist (although walking you through the electrical diagrams would take too long to explain), and happened to our 94 before I replaced both door switches (which can be done through their hole and do not require taking the door apart).
Rember there is a way of putting the CCM into a test mode so that you can 'test' many things, including the door switches -- see your FSM.
Lastly, when buying, carefully examine the switches (from dealer or NAPA). I got 3 sets of 'bad' switches from the dealer (mechanical, poor glueing or electrical issues) before getting good ones. ALso, only use vaseline to lube, other chemicals expand the plastic and cause them to stick.
10-04-2008, 05:11 PM
#9
Melting Slicks
Thanks for the reply, Red Dwarf! I have some answers to your question about the door switches, with an update.
Today's update ...
Yesterday, I lubricated the plunger mechanisms on both door switches, although they have good action.
I also pulled the PKE fuse.
I would have set the PKE system to disable, but the PKE system has apparently already disabled itself - the other day (before I removed the fuse), the light stopped coming on when the key is inserted and the ignition is set to run. Additionally, the PKE system won't respond to the commands of either key fob that I own. However, I haven't tried setting the "recognize new fob" at this point.
I took the car to work today - when I went to the garage this morning, the hatch was secure, but the doors were locked.
At the end of the work day, the car was apparently in the state I'd left it - the hatch was closed, and the doors were locked.
There was some bird poop on the hood, so when I got home, I got out of the car (left it unlocked, since it is in the garage), and proceeded to clean off the bird poop. When I finished that little exercise, I was getting ready to throw away the towel, when the doors locked and the hatch popped open! Additionally, the PKE light was lit on the dash, and stayed lit while I closed the hatch, unlocked the drivers door, and finally put the key in and cycled the ignition to run.
We had some errands to run tonight, so I left the car unlocked, and we left. When I got home a few minutes ago, the doors were locked and the hatch was closed. I unlocked the doors, hoping that it would do the same thing again (lock the doors, release the hatch) - I really want to get this to a repeatable state so I can properly troubleshoot it. Well, I heard the sound of a relay, a very soft horn beep, but no lock cycle. However, when the horn sounded, the interior lights came on (and then went out normally). The PKE light was NOT set, and the doors remained unlocked. So, I thought I would just lock the car and see if the hatch stayed down overnight. When I opened the UNLOCKED door, the alarm system went off (it stopped when I inserted the key and cycled the ignition).
The doors are now locked, the hatch is down, and we'll see what happens overnight.
Questions ...
What does the fuse do? I'm certain that I pulled the PKE fuse!
What made the alarm set, and why didn't it set properly (ie, lock the doors and sound a solid horn beep)?
Does all this relate to a failure of the PKE module? Are they still available from GM? Is there a market for used ones? Would you trust a used one?
Steven
Today's update ...
Yesterday, I lubricated the plunger mechanisms on both door switches, although they have good action.
I also pulled the PKE fuse.
I would have set the PKE system to disable, but the PKE system has apparently already disabled itself - the other day (before I removed the fuse), the light stopped coming on when the key is inserted and the ignition is set to run. Additionally, the PKE system won't respond to the commands of either key fob that I own. However, I haven't tried setting the "recognize new fob" at this point.
I took the car to work today - when I went to the garage this morning, the hatch was secure, but the doors were locked.
At the end of the work day, the car was apparently in the state I'd left it - the hatch was closed, and the doors were locked.
There was some bird poop on the hood, so when I got home, I got out of the car (left it unlocked, since it is in the garage), and proceeded to clean off the bird poop. When I finished that little exercise, I was getting ready to throw away the towel, when the doors locked and the hatch popped open! Additionally, the PKE light was lit on the dash, and stayed lit while I closed the hatch, unlocked the drivers door, and finally put the key in and cycled the ignition to run.
We had some errands to run tonight, so I left the car unlocked, and we left. When I got home a few minutes ago, the doors were locked and the hatch was closed. I unlocked the doors, hoping that it would do the same thing again (lock the doors, release the hatch) - I really want to get this to a repeatable state so I can properly troubleshoot it. Well, I heard the sound of a relay, a very soft horn beep, but no lock cycle. However, when the horn sounded, the interior lights came on (and then went out normally). The PKE light was NOT set, and the doors remained unlocked. So, I thought I would just lock the car and see if the hatch stayed down overnight. When I opened the UNLOCKED door, the alarm system went off (it stopped when I inserted the key and cycled the ignition).
The doors are now locked, the hatch is down, and we'll see what happens overnight.
Questions ...
What does the fuse do? I'm certain that I pulled the PKE fuse!
What made the alarm set, and why didn't it set properly (ie, lock the doors and sound a solid horn beep)?
Does all this relate to a failure of the PKE module? Are they still available from GM? Is there a market for used ones? Would you trust a used one?
Steven
Might be a good idea to try instead of guessing?
10-04-2008, 06:53 PM
#10
Pro
Thread Starter
I have diagnostic scans from the FSM. If interested my e-mail is lsylvestri@sbcglobal.net
Might be a good idea to try instead of guessing?
Might be a good idea to try instead of guessing?
From what I can discern from that circuit, the hatch ONLY opens under three conditions:
1 - Ground the circuit from the PKE
2 - Ground the circuit from the center console button (and if the engine is running, ONLY if the parking brake is engaged enough to switch on the BRAKE light on the dash)
3 - Ground the circuit through the door switch and the door hatch release button, which are connected in series
If the door switch is short circuiting, but the hatch switch is OPEN, then how does the hatch release through a bad switch? Generally, in my experience, switches fail in the open condition, not a short circuit condition (unless they dielectrically break down under high load conditions).
I have reviewed the diagnostic diagrams in the FSM for both the PKE system and the hatch - and none of the conditions match the symptoms I'm describing. For example, the diagnostic chart for trouble shooting the hatch doesn't have any entry for hatch opening unexpectedly - all the diagnostic charts are concerned with a failure of the hatch to open.
As the other poster also mentioned, I'm a bit concerned about the aftermarket switches as well. Based on my initial problem back in September 07, I took a look at replacement switches when I was at Bloomington this year - and all four that I examined had significant tactical feel problems (hard to actuate, and seemed to hang up through the switch travel).
I haven't really tried anything yet - but I'm looking for suggestions about where to start.
Steven
10-04-2008, 08:02 PM
#11
Melting Slicks
I have the FSM - and I'm not trying to guess - I'm looking for an explanation of what's happening. For example, a poster above suggested the door switches as a way to explain the hatch unexpectedly opening, but an examination of the circuit diagram in the FSM doesn't seem to indicate the door switch as an issue.
From what I can discern from that circuit, the hatch ONLY opens under three conditions:
1 - Ground the circuit from the PKE
2 - Ground the circuit from the center console button (and if the engine is running, ONLY if the parking brake is engaged enough to switch on the BRAKE light on the dash)
3 - Ground the circuit through the door switch and the door hatch release button, which are connected in series
If the door switch is short circuiting, but the hatch switch is OPEN, then how does the hatch release through a bad switch? Generally, in my experience, switches fail in the open condition, not a short circuit condition (unless they dielectrically break down under high load conditions).
I have reviewed the diagnostic diagrams in the FSM for both the PKE system and the hatch - and none of the conditions match the symptoms I'm describing. For example, the diagnostic chart for trouble shooting the hatch doesn't have any entry for hatch opening unexpectedly - all the diagnostic charts are concerned with a failure of the hatch to open.
As the other poster also mentioned, I'm a bit concerned about the aftermarket switches as well. Based on my initial problem back in September 07, I took a look at replacement switches when I was at Bloomington this year - and all four that I examined had significant tactical feel problems (hard to actuate, and seemed to hang up through the switch travel).
I haven't really tried anything yet - but I'm looking for suggestions about where to start.
Steven
From what I can discern from that circuit, the hatch ONLY opens under three conditions:
1 - Ground the circuit from the PKE
2 - Ground the circuit from the center console button (and if the engine is running, ONLY if the parking brake is engaged enough to switch on the BRAKE light on the dash)
3 - Ground the circuit through the door switch and the door hatch release button, which are connected in series
If the door switch is short circuiting, but the hatch switch is OPEN, then how does the hatch release through a bad switch? Generally, in my experience, switches fail in the open condition, not a short circuit condition (unless they dielectrically break down under high load conditions).
I have reviewed the diagnostic diagrams in the FSM for both the PKE system and the hatch - and none of the conditions match the symptoms I'm describing. For example, the diagnostic chart for trouble shooting the hatch doesn't have any entry for hatch opening unexpectedly - all the diagnostic charts are concerned with a failure of the hatch to open.
As the other poster also mentioned, I'm a bit concerned about the aftermarket switches as well. Based on my initial problem back in September 07, I took a look at replacement switches when I was at Bloomington this year - and all four that I examined had significant tactical feel problems (hard to actuate, and seemed to hang up through the switch travel).
I haven't really tried anything yet - but I'm looking for suggestions about where to start.
Steven
10-04-2008, 10:21 PM
#12
Pro
Thread Starter
No problem!
Do you agree with my assessment of the hatch opening circuit? I can only see the three ways I posted for it to open. If I assume that I'm correct, then I'm struggling with how a bad door switch (even if it shorts) would cause the hatch to open.
At the same time, I'm observing all this other activity that also doesn't make sense, and it all centers around the PKE module. Sadly, the FSM (as far as I can tell) doesn't explain the three different +B inputs to the PKE module in the wiring diagrams - it just shows that they are there (of course, I only had time for a few minutes of study prior to dinner tonight, so I might have missed something).
Steven
Do you agree with my assessment of the hatch opening circuit? I can only see the three ways I posted for it to open. If I assume that I'm correct, then I'm struggling with how a bad door switch (even if it shorts) would cause the hatch to open.
At the same time, I'm observing all this other activity that also doesn't make sense, and it all centers around the PKE module. Sadly, the FSM (as far as I can tell) doesn't explain the three different +B inputs to the PKE module in the wiring diagrams - it just shows that they are there (of course, I only had time for a few minutes of study prior to dinner tonight, so I might have missed something).
Steven
10-05-2008, 12:47 AM
#13
Drifting
Member Since: Sep 2003
Location: 1994 LT1 Coupe 6-speed with FX3 & 2000 LS1 Vert 6-Speed with F45 Hunterdon County, NJ
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Hi Steven,
I agree with you that the wiring doesn't identify clearly the why's of how the door switches can cause the problem with the hatch popping open, but trust me, it was the reason for our 94, and solved (to never return) 4 years ago when the switches were replaced.
I am working from my memory of 4+ years ago, but I recall there was blocking diode involved and also the CCM and PKE getting out-of-sync do to the input signals being confused thanks to the door switches not reporting consistent info relative to the ignition signals.
Have you tried putting the CCM into test mode to have it advise (via the dash) the 'state' of the switches?
Also, I found the GM switches to be the worse --- but that was 4 years ago, don't know if they have gotten any better. THe switches from NAPA were not as bad (though appeared to be made by same manufacturer).
In either case, I'd try whichever one is easiest to acquire, but look it over first.
I agree with you that the wiring doesn't identify clearly the why's of how the door switches can cause the problem with the hatch popping open, but trust me, it was the reason for our 94, and solved (to never return) 4 years ago when the switches were replaced.
I am working from my memory of 4+ years ago, but I recall there was blocking diode involved and also the CCM and PKE getting out-of-sync do to the input signals being confused thanks to the door switches not reporting consistent info relative to the ignition signals.
Have you tried putting the CCM into test mode to have it advise (via the dash) the 'state' of the switches?
Also, I found the GM switches to be the worse --- but that was 4 years ago, don't know if they have gotten any better. THe switches from NAPA were not as bad (though appeared to be made by same manufacturer).
In either case, I'd try whichever one is easiest to acquire, but look it over first.
