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Comments
I just inherited a 2004 Pontiac Grand AM 3.4 from my grandmother who rarely used it, its got 40K miles on it. Yesterday the car wouldn't start and I had it towed to the mechanic. Last night I read your very helpful description of how to deal with the Pontiac Security Problems and I went to the mechanic this morning to see if this might be the issue. When I got there they had gotten the car to start again and it was working fine, the mechanic said that he started it by manually grounding the PCM, but he didn't think that it was a passlock problem because he said that the security light on the car wasn't on, even though I remember the security light being on when I had the car towed. In addition he said that everything else, all the wiring, new battery, etc. was working fine. He said that I need to replace the PCM and is going to charge me $1200 to do it, $800 for the part, $150 for the work and another $150 to reprogram it.
I am a new car owner and don't know too much about cars, but is the PCM the same thing as the BCM that you are talking about in your post? Is it possible that its still a passlock problem? Or is this just my wishful thinking? We most definitely cannot afford to spend $1200 so the car will probably not get fixed.
Thanks so much!
There is no place in the service manual that refers to "Grounding the PCM". In order to work on the PCM, the service technician needs to have two electronic items.... a Tech 2 Scan tool, and a Techline Terminal. These items are needed for the Powertrain Control Module (or Engine Control Module) to learn the variations of the Crankshaft Position Sensor, and also so the new PCM can learn the correct data code for the Theft Deterrent System. (the password sent by the Body Control Module) I would not feel comfortable having my PCM replaced by a mechanic who did not own those items, and I would certainly ask what he means by "grounding the PCM???"
If the car is now running, why not take it back and drive it, and see if it runs ok, without any "Check Engine" lights coming on. If it does, keep driving it. If it should quit on you, be very observant of the dash lights that are on, and have a mechanic read the trouble codes from the ALDL connector... or you can buy a scan tool that will connect to your smartphone that allows you to read the trouble codes yourself. [on the internet, look up "ELM-327" scan tool]
It would be a rare thing for the PCM to go bad on a car with only 40000 miles, and if it did, it should be covered by warranty, since the Environmental Protection Agency requires that all vehicles pass emission testing for at least 50000 miles. The PCM monitors all the emissions sensors, and tunes the fuel supply to insure that emissions are at a minimum.
I hope this information helps you make an informed decision. Your vehicle is certainly worth keeping, but I would get a second opinion from a second reliable technician before replacing the PCM.
Your information about the things that cause the passlock problem are for the most part correct. The security system is too fragile, but not because of the computer system. In general, the Body Control Module is seldom the cause of the problem. The weak link is the Passlock circuit which is embedded in the ignition module. This module can fail for several reasons:
* wear of mechanical parts, causing the magnetic switch to fluctuate in resistance.
* lubricant in the mechanical switch causes metal particles to collect near the moving magnet, causing the magnetic switch to fail to operate properly.
* poor quality connectors in the three signal wires that form part of the Passlock circuitry.
The software engineers at GM took great pains to insure that none of the possible failure modes would cause a running vehicle to stall while driving, as this would have constituted a safety hazard. Additionally, they provided a work-around that would save the customer from a "walk home" condition with the 10 minute relearn procedure, which is clearly described in the vehicle owner's manuals.
The easiest fix for this problem is the bypass described at http://www.bergerweb.net/PasslockFix This fix takes less than $5.00 worth of parts, and can be done in 20 minutes by anyone who can follow instructions and has a rudimentary understanding of electricity.
While the BCM is easy to replace, the cost of replacing it will be much more than you would expect. Each BCM is programmed at the factory to match the electrical components in the body of the vehicle, which varies depending on the options installed. When a different BCM is installed on a vehicle, it must be programmed to recognize such things as:
* does this vehicle have Remote Keyless Entry?
* How many Remotes does the owner have?
* Are there electric windows, or manual windows?
* What kind of radio is installed
* Must learn the correct theft code to enable the radio
* must learn the correct value transmitted by the Passlock module.
* must synchronize the Anti-Theft password with the Powertrain Control Module
* many more.
To program a new BCM, the vehicle must be brought to the dealer, who has the required terminal and Tech II scan tool. The programming part of the installation is specified in the shop manual as a 0.6 hour charge, so be prepared to pay about $75 for that service.
In summary, I would not advise anyone to try replacing the BCM themselves, as this is not the most likely problem, and would cost more than you expect to get the vehicle running again. Only after trying the cheap bypass trick in the above link, should you consider having the BCM replaced.
Also, don't worry if your key is a bit loose in the ignition switch. The key does nothing more than allow you to turn the cylinder in the lock. There is no circuitry associated with the key.
R Berger
Engineering Staff
General Motors Proving Ground
Milford, Michigan
Your 2003 Grand Am DOES NOT take a key with a chip in it. It uses a normal Ace Hardware key, with no embedded electronics.
The Passlock System can not be disabled by a key fob. If you have had some other security system installed on your vehicle, such as an alarm, you may need a keyfob to disable it, but the Passlock system doesn't operate that way.
Your symptoms do indicate some sort of parasitic draw from your battery. How did you relate that to the BCM?
There's one of your problems right there. Don't pay too much attention to the Autozone guy for troubleshooting advice. With that said, I would suspect the ignition switch based on your description.
What is the battery voltage when the battery is at rest (engine not running)?
I agree though that this doesn't sound like it has anything to do with passlock.
My Chevrolet Dealer in Fenton, MI. charges $25 to reprogram the BCM to accept two new Remote Keyless Entry Fobs.
I tried putting the radio back into the car and got the same result, all I could achieve was turning on the the power. But, another weird thing I noticed is now the key slide right out of the cylinder while it is in the "on" and "acc" position. Could this point to a bad cylinder? aswell as security issue.?
Thanks in advance. Hope someone has an answer for me...its been a weekend nightmare.
Thank
Linda
Is the "security" light flashing when this occurs?
Also, the security light is not flashing at all.
I talked to a local technician and it maybe the ignition switch...the key slides right out of the cylinder when set to on position. Its strange.
If you have any input please share...Im going to start at the ignition switch though and work from there
1. When removing the radio, somehow you disturbed the wiring that was installed for the remote starter, in which case, you will probably have to take the car back to the people who installed the security system. In my experience, these installers are not electronic savy people... usually just someone trained to follow instructions to the letter, and not very good at diagnosing problems. Your best bet is to ask the security system installer for schematics of the installation for your vehicle, and then troubleshoot the problem yourself.
2. Your Park/Neutral switch may be out of adjustment. As you try to get the car to crank, try wiggling your gearshift lever, and see if that allows your starter motor to operate. (On stick shift, you must have your clutch pedal to the floor for the starter to operate)
The operation of the starter motor is not related to the Passlock system. You will find a wiring diagram of the starter system at:
http://www.bergerweb.net/graphics/Starting-Charging-Wiring.gif
This will allow you to troubleshoot the no-crank situation. Let us know what you find out.
If your key can be removed in any position other than OFF, then damage has been done to your ignition cylinder, and you should probably replace it. My guess is someone tried to steal your car, but you were unlucky, and they didn't succeed. (dark humor)
Do this:
1. Turn the ignition switch to the run position. Wait until the bulb check is finished. (about 3-5 seconds) At that time, the "SECURITY" lamp should be out.
2. Turn the ignition switch to the START position. The engine should crank, and within a couple of seconds, it should begin to run.
If the engine does not fire up, you have one of three problems:
A. There is no fuel being delivered to the injectors, or the injectors are not operating properly.
B. There is no spark at the spark plugs, so the fuel is not igniting.
C. The timing is incorrect.
Check to see which one is your problem, and you will be able to repair your problem.
Your ETS and ABS systems can be effected by dirt and grime in the front brakes. There are wheel speed sensors in that area, and dirt can cause them to send incorrect speed signals to the computer system. I believe that is controlled by the powertrain control module, so it would not have any effect on the Passlock system.
You didn't say what model vehicle you have. The Passlock system is used on the following cars:
1999 - 2004 Oldsmobile Alero
1997 - 2003 Chevrolet Malibu
1999 - 2004 Pontiac Grand Am
And several GM Trucks
First of all, we never lock our car doors. We figure if someone wants to steal our hunk of junk, they are more than welcome to, so when I went to leave for store today I noticed my car doors were locked. So that was pretty odd, next when I got in the car I noticed the brake pedal went all the way to the floor with no pressure behind it at all. It was very noticeable and at first I thought I had no brakes, but after testing them, they worked but still no pressure behind them.
I stopped at the gas station to fill up and when I went to leave, my car refused to crank. It would act like it was about to turn over and I would try to give it gas, but it would not turn over long enough for me to even do that. I sat for about 20 min trying and nothing, so I pushed it to a spot and called someone to pick me up. Locked the doors and let it sit for an hour. I came back and tried to unlock the driver side door but it would not unlock with my key. I went to passenger side which is no longer controlled by the auto lock feature and got in.
We once again tried to turn it over but nothing. Something we noticed during was the theft lock warning light nonstop flashing, so this is making us think it is an issue with the theft lock.
I definitely don't have the money to put this car in the shop and it is our only car, so I am hoping someone can help me figure out what I can do. Is there anything we can do to get it to turn over. I have read things for other cars about letting the key sit in the on position for 15 minutes and then it should crank, but I don't know if that would work on a Pontiac. Any tips would be greatly appreciated.
This symptom indicates either a weak battery, or a poor connection to the battery. With a reasonably strong battery, your starter should be able to turn over the engine for at least 60 seconds. A weak battery could also cause an improper signal from the security system, which may cause the theft lock warning light to blink. Also, I have had experience with other GM cars locking the doors when the battery was low.
Disconnect the battery cables from the battery, and check to see if there is corrosion on the contacting surfaces. Once you make sure they are clean, re-connect the cables to the battery, and try starting again. If that doesn't work, make sure the battery is fully charged. Leave the charger connected to the battery, and turn on the ignition. If the theft lock light is blinking, let the car sit with the ignition switch in the on position for at least 15 minutes. The theft lock light should extinguish. Then you should turn the ignition to the off position, let it set for a few seconds. Turn ignition to on for a second or two, then turn it to crank position. The car should start, and the security light should be off. Note that when you first turn the ignition switch from off to on, the vehicle will perform a "lamp check" for a few seconds. During that time, all the warning lights on your dash will be on. This is normal. After the lamp check, only the Oil pressure, battery, seat belt, and ServiceEngineSoon lights will be on. These should extinguish once you crank the engine.
Spending $425 on a new ignition switch was a waste of money for you. Go back to the beginning of this thread (just before the first post on this page) and click on the link labeled "GM Security Passlock Fix"
This FIX is mentioned at least 20 times in this thread. I'm surprised that anyone would have missed this after finding this forum.
Am so lost...
Okay, unlike most people, I think we’re the only ones on Earth that had a problem with the security light being solid as opposed to flashing. I was debating on the toggle but ended up doing the bypass using a resistor. Well one store, I won’t mention which one, gave me the wrong resistor twice (first a 220 ohms, then a 22000 ohms) so it wasn’t working, although I didn’t know they made a mistake twice until reading the receipt (the package said 22K ohms and I was thinking 22 kohms, not 22 (thousand), wasn’t thinking about the decimal [2.2]) – don’t know if it will even work now that we tried it without realizing the 22000 ohm; we had it hooked up and everything and I’m not sure what it would or has done to it. Could I really be part of the small percentage again that this wouldn’t work for??? I am at my wits end because I went back and decided to measure for the ohms and it seems like the yellow wire is getting nothing unless I’m doing something wrong! Then I learned about doing it with a terminal switch a little too late. At one point I almost had it without knowing by turning the key to “on” and barely pushing it to “start” – this would turn the security light off but I didn’t read much on it because that didn’t come up much so I figured it wasn’t a fix. I was excited at first but doing it wrong, it never started my car and I didn’t find another resource of doing it that way until *after* cutting the wires! This has been nothing but a major headache for us and we can’t afford a shop!! We are doing all this by the kick panel on the passenger’s side of the car but we looked under the stereo too out of curiosity and nothing moves under there, it’s too tight; the wires are snug in their place!!
When I test the black wire and the yellow wire (coming from the ignition) there is NO ohm reading, doesn’t change the meter at all! I cannot get to the wiring behind the stereo, literally seems like you have to remove the dashboard – not happening on this end until I get absolute no other answers. Did GM really make it this impossible for the OWNER to use his/her own car!!! How dumb can they be????
* Incorrect spark or valve timing
* Weak spark, or no spark on half the cylinders
* Insufficient fuel flow to maintain engine rpm.
Any one of these three can cause the symptoms you are having. If your "Security" lite is not lit, you have solved your Passlock issue, and need to try other solutions. I would start with a new fuel filter. Then check for good fuel pressure, then for proper ignition. and timing. A bad crankshaft position sensor can also cause the problems you are having. Please post back with the engine you have in your vehicle.
R. Berger
Sorry for having sounded harsh about your passlock problem and the solution you chose. I completely understand your apprehension about using what most would call a "Shadetree mechanic" approach to solving your problem. My main reason for staying in touch with this forum is to help those who are not willing to invest $450 to repair a car whose value is less than $2000, and are looking for an alternative.
I would advise you to keep your receipts. Many people who have posted here, and on other forums have had the dealer fix their problem, only to have it re-occur within 6-10 months. Also, most dealers, when encountering this problem, will replace the ignition switch first, and not bother to check for broken or intermittent wiring in the dashboard area. At any rate, please accept my apology for my harsh wording, and good luck.
http://www.bergerweb.net/grandamsecurityfix.htm
http://bergerweb.net/PasslockFix/index.shtml
http://bergerweb.net/AleroSecurity/index.shtml
Please note: I have done these modifications on...
8 2002 Pontiac Grand Am's
3 Olds Alero's 2001, 2003
1 2000 Chevy Malibu
Alll of them have worked, but each mod was performed on cars that had been having the passlock problem, but the 10 minute relearn procedure would work.
When the Security lamp is on solid, it means that the Body Control Module has gone into the "Fail Enable" mode, meaning that there is "something" wrong with the Passlock system.
A quick note:
When you turn the ignition to ON, the BCM performs a Lamp Check, during which time ALL of the warning lights on the dash should be on. After the initial 3-5 seconds, all the lights should extinguish except the Oil, Battery, Service Engine Soon, and Seatbelt lamps
I have a 1998 Grand AM SE 2.4 cylinder vehicle. Will any of these tutorials work? They all look like they are for 1999 and later vehicles?
If they won't work do you know where I can find one that will?
Thanks
http://bergerweb.net/PasslockFix/index.shtml
You can subscribe to online shop manuals for around $27.00 at Alldatadiy.com
Your problem seems to have more to do with ignition, rather than a Passlock problem. My first instinct would be to have a mechanic check your ignition modules. (you have two of them, each serving two cylinders.) If one ignition module or coil is defective or intermittent, it will cause the symptoms you are experiencing.
You may also have a defective, or intermittent crankshaft position sensor.
Normally, I would also suspect a clogged fuel filter, or a defective fuel pump, but it's doubtful that either of these would cause your fuel consumption to jump so high.
Have your mechanic also check to make sure your valve timing is correct.
The passlock system, when activated, will keep your engine from running at all. Sincy your car runs, there must be some other problem causing your poor performance. Hope this helps.
I posted this in another section but this seems to be more on topic.
Got in my 2002 Grand AM that had been running. Acts like the known security problem where it will starts for a couple seconds and quits. At same time the dome light, radio, and door locks stopped working. Battery has juice and I did the waiting 10 minutes security fix so well documented on the internet but didn't fix the problem. Took a while but the battery finally died but I jumped it and again tries to start but dies right away. Still no dome light, radio, and door locks. Didn't change anything.
Any help would be greatly appreciated.
Thanks,
Jim
Your engine symptoms indicate a lack of sufficient fuel delivery. Either a clogged fuel filter, or weak fuel pump will cause that. When the passlock system activates, you only get a momentary start the first time it happens. From then on, it will not fire up at all.... not even momentarily, until you perform the 10 minute reset, and your "Security" Light is extinguished.
The car does start for a few seconds more than once. Starts for a few seconds then doesn't the next maybe two times then it starts for a few seconds and the same patern continues on staring for a few seconds once in a while. Based on what you said about not starting for a few seconds more than once would rule out the security problem.
I can hear the fuel pump start. So it is something that impacts getting enough gas while also effecting the dome light, radio, and door locks. So you suggested the BCM. Do you think it could possibly be the ignition switch?
Thanks for your help.
Jim
Yes, a faulty ignition switch could be the problem, though it's likely that if it were the ignition switch, there would be other problems as well.
The Ignition switch furnishes voltage to parts of the Body Control Module. Power for the Body Control Module is also supplied directly from the battery. There are also several fuses that furnish power to various relay circuits within the Body Control Module. I would advise you to check all your fuses to make sure they are good before replacing anything else.
Here are links to four diagrams that may help you to trace your problems and find the fuses that could be causing your problems.
http://bergerweb.net/graphics/UnderhoodFuseBlockLabel.gif
http://bergerweb.net/graphics/BCM-Schematics1.gif
http://bergerweb.net/graphics/BCM-Schematics2.gif
http://bergerweb.net/graphics/BCM-Schematics3.gif
I hope this helps. If you find out what your problem is, please post back.
Dick B.
Thought you find this of interest. I just turned 142K on my 04Grand Am GT. It's never been in the shop for anything. Besides regular maintenance, I've changed the multifunction switch (myself) the water pump (myself, easy job on the V6). The water pump wasn't leaking that you could notice, but during the last oil change I looked up while changing the filter and noticed the tell tale signs of orange dexcool being slung around off the water pump pulley onto things close by, so I went ahead and changed the pump since it could be starting to dribble a little. The old pump did have a good amount of play in the shaft.
I relined the brakes recently also, and this time I went ahead and changed the rear pads also (original pads) thinking that with those miles they must be low. After getting the calipers off though they could have easily gone another 20K or so. Since I had it apart I went ahead and put the new pads on.
I can't complain, it's been one of the most reliable cars I've ever owned.