Question about 1998 Chevrolet Tahoe

1 Answer

I have a 1998 Chev Tahoe and I'm replacing the keylock cylinder. I'll prob have a prob. with the passlock system. How do I program the key to work?

Posted by on


1 Answer

  • Level 3:

    An expert who has achieved level 3 by getting 1000 points


    An expert that got 10 achievements.


    An expert that got 5 achievements.


    An expert whose answer got voted for 500 times.

  • Master
  • 447 Answers

Well, this is how it's supposed to work but I have had to resort to using a GM specific scan tool when I couldn't get it to relearn.
1. With vehicle in Park, turn the key to the crank position briefly [do not start engine but just bump the starter so the engine turns over about 1/2 a turn] then release the key and let it remain in the "run" position. The security light should flash for a few seconds then stay on for about 10 minutes.
2. At the end of about 10 minutes, the security lights should go off so watch closely. Once it goes off turn the ignition key "off" for about 10 seconds then repeat step 1 two more times which should add up to about 30 minutes total of time spent.
3. After you have finished the 3rd of the 10 minute cycles, leave the key off for about 20 seconds then try and start the engine. If it should be ready to go. If not, then you may need to have someone with a scan tool help you out. Like I say, it SHOULD work but I have found some aftermarket key cylinders that I just can't get to relearn so you may need an OEM cylinder [I would suggest it actually]
Good luck, hope this helps you out.

Posted on Aug 03, 2010


1 Suggested Answer

  • 2 Answers

SOURCE: I have freestanding Series 8 dishwasher. Lately during the filling cycle water hammer is occurring. How can this be resolved

Hi there,
Save hours of searching online or wasting money on unnecessary repairs by talking to a 6YA Expert who can help you resolve this issue over the phone in a minute or two.

Best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.

Here's a link to this great service

Good luck!

Posted on Jan 02, 2017


Add Your Answer

Uploading: 0%


Complete. Click "Add" to insert your video. Add



Related Questions:

1 Answer

How to program key to ignition for a 1998 Chevy truck w/vortex v6 engine..I tried it myself an it did crank but will not stay running

Program KEY ? There is no transponder in the key for a 1998 Chevy truck . What problem are you have ,no start ? Is the SECRUITY light lit on the dash ? you don't need to program keys with this ant-theft system .
Vehicle Theft Deterrent (VTD) Operation
The design of the passlock system is to prevent the vehicle operation if the proper ignition key is not used in order to start the vehicle. The mechanical key, in normal operation, will turn the passlock lock cylinder. The passlock sensor will relay the passlock data to theEVO/Passlock module. The EVO/Passlock module will determine the validity of the passlock data. The EVO/Passlock module will send a code password to the vehicle/powertrain control module (VCM/PCM). When the VCM/PCM receives the correct code the VCM/PCM allows the fuel injectors to operate normally. The passlock system requires the VCM and the EVO/Passlock module to communicate the various functions in order to operate. These functions transmit over the class 2 serial data line CKT 1807. For an explanation of the class 2 serial data operation refer to Data Link Communications Circuit Description in Wiring Systems.
Passlock System
The design of the passlock system is to prevent vehicle theft by disabling the engine unless the passlock lock cylinder rotates properly by engaging the correct ignition key. The system is similar in concept to the passkey system. However, the passlock eliminates the need for a key mounted resistor pellet. The components of the system are as follows:
The ignition lock cylinder

The ignition switch

The passlock sensor

The EVO/Passlock module

The security indicator

The vehicle/powertrain control module (VCM/PCM)

Nov 29, 2015 | Cars & Trucks

1 Answer

Security light stays on

Annette: According to : " Passlock is a second generation General Motors' theft deterrent system. With the use of a Passlock sensor (mounted in the steering column) the Passlock system can determine improper ignition key and lock cylinder operation by monitoring magnetic fields emitted by the lock cylinder assembly. Once improper operation is confirmed, engine startup is disabled.
The Passlock system eliminated the resistor chip mounted in the ignition key used by the previous Passkey system, including the headaches and expense that went along with it.
Passlock is a subsystem of the vehicle's Powertrain Control Module. The Passlock sensor sends a signal to the Passlock control module. The Passlock module reads this signal and sends the appropriate information to the Powertrain Control Module. If the ignition key and lock cylinder operates normally the engine will start as usual. If it was operated improperly the Powertrain Control Module will be directed to disable fuel injector operation, prevent engine startup, and there will be a diagnostic trouble code set in the Passlock Control Module's memory.
I just wanted to give you an understanding of system operation. It's gonna require the correct scan tool for proper diagnosis. Weak links are the circuits to and from the Passlock Sensor in the steering column. It's a very sensitive signal and can be easily affected by shoddy electrical connections.
If a scan tool displays diagnostic trouble code B2960 (Passlock sensor voltage out of range), the next step would be a resistance check and a complete inspection of connections and wiring involving the sensor. Pay the diagnostic time at a heads-up auto repair shop."

May 13, 2015 | 1998 GMC Sierra

1 Answer

Is there a security sistem in a gmc ck3500 98

yes usually the 2 white wires break inside column that mount to lock cylinder assembly, try turning key on for 10 min than off than on for 10 min than off than on for 10 min.then try and start if starts and stays running will prob. need passlock sensor which is part of ignition lock cylinder

Feb 25, 2013 | 1998 Chevrolet Tahoe

1 Answer

Key stuck in ignition pontiac sunfire

ignition keylock cylinder broke. you have to remove ignition switch and remove keylock cylinder and replace ignition switch keylock cylinder with new ignition key then you have to reset theft security system which dealership has to fix.

Jan 27, 2013 | 1999 Pontiac Sunfire

2 Answers

Light came on it said theft sys

Your theft system is enabled. The car will only start and die if it will even start at all. More than likely it just turn over and wont start and this light is flashing you in the face. You need a new passlock sensor. It is located in the steering column and is part of the ignition switch lock cylinder. The lock cylinder must be replaced as a unit with the passlock sensor and match your existing key code so they will need the key...OR if you have a TOP NOTCH lock smith in town, take him your original key and they can program a small modual to match your key that plugs into the passlock sensor main wiring harness ( going to the computer and not the steering column ) at the base of the steering column to bypass the one in the ignition housing. I know they make them because I have put 4 in over the last 2 months. 2 pontiacs, 1 cadillac, and 1 chevy tahoe. It beats the heck out of tearing the steering column apart!

Aug 02, 2011 | Pontiac Grand Am Cars & Trucks

1 Answer

I have a 1998 chevy tahoe that will not start sometimes because of the passlock security system does anyone know how to disable it or fix it so it will let me start it

You can either replace the lock cylinder or bypass it by adding a resistor in the line that makes the ecm think it has the right lock cylinder in it.

Feb 13, 2011 | Chevrolet Tahoe Cars & Trucks

2 Answers

Security light flashes,and car want start,except bye the starter,and suddenly stops.

Depending on the year of vehicle how the security system works (you didn`t specify year or model). Older models up to 1997 use passlock I, they have a chip in the shaft of the key, and usually break in the steering column just behind the ignition key cylinder. You will need to know the code number of the key, and will have to order a new ignition cylinder and new keys. After 1997 its passlock II which has the chip inside the head of the key. It learns the code of the key and ensures its the correct key every time you start the car. The most likely problem with this system is the passlock sensor in the ignition switch. Try turning key to run (do not crank) leave key on for 10 minutes, the security light should be flashing. When it stops flashing or goes solid (after 10 min relearn) try to start again. If starts you will need the passlock sensor soon. It probably has a trouble code set in the BCM (body control computer).

Feb 02, 2011 | Buick LeSabre Cars & Trucks

1 Answer

Passlock system in my 98 Chev Tahoe needs reset.Is there something I can do? Starts up then turns fuel off to injectors after 1 second.

unlock door with key?
or after it dies leave key on for 10 min-
theft light will go out
then start without shutting off key
that should do it

Jul 25, 2010 | 1998 Chevrolet Tahoe

1 Answer

1998 Chev Malibu starts then stalls

The most likely cause for the problem you are describing is the anti-theft system. GM calls it a passlock system. Your car has a 'key-reader' mounted on the ignition lock cylinder (inside the steering columnm, or inside the dash, depending on where your key goes). This 'key-reader' sends out a signal to the body control module indicating that the proper key is in the ignition. Note: this style antitheft system does not have 'chip' in the key. These key-readers fail frequently and send a an incorrect singal the the module, where the car will start and run for a few seconds, then stall. An easy verification of this problem is to watch for your security light to be flashing somewhere on your dash. The passlock cylinder is only available from the dealer, and while it is a fairly easy part for someone like me to change, I do not recommend it for someone who is not a mechanic. Additionally, even if you do change the passlock cylinder, you have to perform a re-learn procedure or the car will never start. This probably isn't the answer you wanted to hear, but better that you know. Hope this helps!

Feb 01, 2009 | 1998 Chevrolet Malibu

Not finding what you are looking for?
1998 Chevrolet Tahoe Logo

122 people viewed this question

Ask a Question

Usually answered in minutes!

Top Chevrolet Experts


Level 3 Expert

81400 Answers

Colin Stickland
Colin Stickland

Level 3 Expert

22359 Answers

Ronny Bennett Sr.
Ronny Bennett Sr.

Level 3 Expert

6927 Answers

Are you a Chevrolet Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides