Rod Bender

How can I bypass the key start part of my starting system? Often when I turn the key the starter does not turn over. The dash lights and radio go on like normal. When I get under the car and jump across the starter (which I have already replaced more than once) it turns over. When I jump across the neutral safety switch still nothing. Chevrolet quotes me $900. to replace both the lock cylinder and switch.

Skedaddle

Have you read Shoebox's "how to" on replacing the ignition switch? Also includes some diagnostic info:

4th Gen F-body Ignition Switch Replacement

Why do you need to replace the lock cylinder?

Rob also has diagnostic info on the VATS system:

4th Gen LT1 F-Body Tech-PassKey/VATS

Rod Bender

Thanks for the information, Skedadle. From what I have been told, my problem could be in the lock cylinder as well.

Injuneer

The lock cylinder has the two contacts the read the resistor pellet in the key. That's it. It is connected by a rod to the switch. If the resistor signal isn't being read, the "SECURITY" light would be on solid (wrong resistance) or flashing ( no resistance reading). If the rod is a problem, it'usually a matter of adjustment.

Rod Bender

Thank you for the information, Fred. You make it sound simple. I'll read over Skedaddle's post and see if it is simple enough for me to do. I already had the air bag off and was ready to take the steering wheel off, was ready to buy Auto Zone's switch and cylinder for about $85. when I checked with Chevrolet and they said they sold the switch for $150. and the lock cylinder, key and programming and labor was $750. And they would not program someone else's key. I was thinking maybe I could get a universal type starter solenoid like what they used to have on old cars maybe from a tractor supply dealer that could carry 100 to 200 amps, use a push button for the switch and still use my key to turn on the ignition.

94Z28LS1toLT1

Hello there 900 is a lot,my ignition switch cost 180 at the dealership,but the parts guy told me "to do it myself bcuz the dealership is gonna charge you a lot."I have the Chilton n Haynes Manuel n I followed everything in order to do it,after i was done ignition switch was perfect,the best to you man on ur problem

GaryDoug

There is nothing special about the starter on your car. It is a simple starter with a built-in solenoid that only requires a few amps to operate. Almost any switch can do the job to operate the solenoid.

Rod Bender

Thanks 94Z. I thought about going original, but the keyless entry thing worries me. Not that I want to keep it, it is more of a pain, but as I understand it, it has to be programed by the dealer from my vin number. I like Gary's suggestion if I can just wire into the starter solenoid with a pushbutton. However, I am not sure how to connect the wires. I would hate to screw something up.

Injuneer

If there is a problem with the cylinder you can buy a new one and have it set up for your existing key. As long as you use your existing key, or even a new one with the correct resistor value, there is no programming required. Often, all the cylinder needs is a good cleaning of the pellet contacts with a Q-tip and some electronic cleaner.

As far as the procedure for replacing the switch, Shoebox's is superior to the factory manual, Chiltons or Haynes, with numerous photos.

I'm not telling you the replacement is "simple"... Not sure why you feel that way. That is not my objective. I'm trying to tell you the diagnostic is relatively easy and necessary. Unless you have done the diagnostic and determined that the switch is faulty, you could just be wasting your money. I hate to see dealers rip people off.

Rod Bender

As I understand it, only Chevrolet can program a lock cylinder which has to be one of theirs at $600. I agree on diagnosing, I read Shoeboxes how to, but I must have missed the diagnostic. All I saw were things that could go bad. I could replace the switch and harness with maybe a more reliable one from NAPA than Auto Zone, add a resistor to eliminate the security system and I could save myself from being stranded while crossing Alligator Alley sometime.

Injuneer

Did you use a test light to determine which circuits are getting power? Rob mentions that.

I have never heard of any programming needed when replacing the lock cylinder. Look at Shoebox's PASS-Key schematic. The cylinder has two contacts that read the resistance of the key pellet. Nothing more than that.

But apparently a dealer has convinced you that you need to spend $900 to replace the cylinder and switch, so go for it. There is apparently nothing I can do to convince you otherwise.

GaryDoug

Or maybe you could just prepare in advance by making or buying the resistor device and keeping it in the car somewhere, like I have done. There is nothing to program in the cylinder. You may be thinking of a newer car.

Rod Bender

Since my situation is that when the key is in the on position and everything except the starter seems to be working (and even it works at times except usually after things have warmed up), can I install the resister to eliminate the possibility of a bad PDF causing problems, and a push button wired to the starter solenoid to allow the starter to operate? Also, as I understand it, if I get a new switch and key module the key the security system has to be made to recognize the new key.

GaryDoug

I will try to explain this again. The body control module reads the resistor value in the key via the contacts in the key cylinder. If it doesn't read the correct resistance, it turns on the Security lamp (after it normally shuts off), cuts off the circuit to the starter solenoid via the theft deterrent relay, and tells the pcm to not pulse the fuel injectors. If the BCM instead reads an open circuit while the engine is already running, it flashes the Security lamp and disables the anti-theft system so it can be started the next time. The thinking there is that the key worked once to start the car, so it must be a circuit failure.

So you see, just running a switch and wire to the solenoid only fixes the starter issue, not the injectors issue. If you are seeing the Security lamp on way after it normally shuts off a few seconds after the key is turned to Run, the resistor isn't being read correctly. Replace the cylinder and wiring, or install a substitute resistor into the unplugged connector under the steering column to bypass the key's resistor. It can be permanently attached or temporarily like in my photo. If the Security light turns off a few seconds after the ignition is switched on, that key/resistor isn't the problem. Look elsewhere.

The BCM will never recognize a new key that has a different resistor value. The BCM can only be programmed once, and that is already done when new. You would have to have a matching resistor key blank cut to match the new lock. New blank keys cost about $10-15. I had mine cut at home Depot for free.

Rod Bender

Duh! Thanks for the explanation. The security lite doesn't stay on if the engine starts, but will flash on for a few seconds occasionally while the engine is running. If I install the resistor would that circumvent the possibility of the security system shutting down my engine? Also, where do I get this resistor?