Ignition switch problem
Thread Starter
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Joined: Jan 2002
Posts: 1,755
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From: Houma, LA
Ignition switch problem For several months now, my Security light has been lighting up on the dash. My car has no power options, therefore no alarm. I have been told this is a problem with the ignition switch. Now, what I need to know is, is this a problem, with the cylinder, or just the switch. The car had been starting without a problem at first. At one point, which IIRC was before the Security light started coming on, the car wouldn' t start on the first attempt, I would have to let off the clutch, and get back on it. As of late though, the car is getting extremely temperamental! No matter what I do, it' s hard to start. I' ll turn the key, my dash lights go out (as they do when starting the engine), and I hear a click in the dash, but absolutely NOTHING from the starter. No click. No grind. My dad thinks it' s my starter, but since it NEVER grinds, I don' t think that' s the culprit. I' m thinking it' s the ignition cylinder not reading the VATS chip. Could that be the problem. If so, do I have to buy a cylinder with the same chip and key pattern as stock (I found more than one cylinder on a website with different part numbers for the same vehicle), or will any cylinder work? The VATS chip is read by the PCM, right? So the cylinder should have no bearing, as long as the contacts pick up the chip. Right?
The cylinder does not need to match the key but the key will need to match the BCM.
A new BCM will "learn" the key.
The "VATS chip" is just a resistor.
The BCM feeds the cylinder 5v and
expects to receive the signal from the key
in order to send the fuel enable signal to the PCM.
If it doesn't then it won't enable the starter and/or
will not send the PCM the signal to enable the fuel pump.
A dirty"chip" in the key or not seating the key fully can
cause what you are experiencing, as well as a faulty cylinder.
Attachment 207400
A new BCM will "learn" the key.
The "VATS chip" is just a resistor.
The BCM feeds the cylinder 5v and
expects to receive the signal from the key
in order to send the fuel enable signal to the PCM.
If it doesn't then it won't enable the starter and/or
will not send the PCM the signal to enable the fuel pump.
A dirty"chip" in the key or not seating the key fully can
cause what you are experiencing, as well as a faulty cylinder.
Attachment 207400
Last edited by shoemike; Dec 18, 2009 at 12:59 AM.
Joined: Nov 2003
Posts: 11,332
Likes: 347
From: Jacksonville, FL (originally from Toronto Canada)
It is possible but unlikely that the problem is in your ignition cylinder. Usually it's the ignition key. As shoemike said, the contacts on the key pellet get dirty causing the system to misread the resistance. Use some rubbing alcohol and a pencil eraser to thoroughly clean the contacts on both sides of the key. You can also clean the contacts inside the ignition cylinder by spraying some electrical contact cleaner (available from Radio Shack) into it and working your key in and out to dislodge the built-up grime. You could also try using your spare key if you have one.
If that doesn't solve the problem, bypassing the VATS system is far less expensive than replacing the ignition cylinder. Instructions fr the bypass including photos are posted here.
If that doesn't solve the problem, bypassing the VATS system is far less expensive than replacing the ignition cylinder. Instructions fr the bypass including photos are posted here.
Thread Starter
TECH Fanatic
Joined: Jan 2002
Posts: 1,755
Likes: 0
From: Houma, LA
Thanks guys! That solves have the problem. Security light still comes on. It was a combination of two things. The contacts in the cylinder were dirty, and the contacts on the chip are worn pretty low, the key has over 147k miles on it.
