Broken 1998 Chevy Blazer Passlock

The security light is on on the dash. The truck starts but will not continue running. The alarm seems to be defective and shutting the supply of fuel off. It is a 1998 Chevy Blazer with a 4.3. Is there a bypass system available so that i can bypass my factory alarm to allow it to drive. I do not want remote start, locks and such. Thank You

So if I am understanding right, then you have no type of aftermarket system in there whatsoever, its just the Passlock system cutting out right?. You could use a passlock bypass system from a company like DEI but I believe you need the passlock system working right to start with to program it, and the ones that you set manually are still gonna require a properly working system to get the correct value to set the module to.double-secret reverse-osmosis speaker-cone-induced high-level interference distortion, Its a killer

In regards to your 98 passlock 2 system, a simple way to bypass the system when it is not working correctly is to get the vehicle running, locate your passlock wires in your column. There will be 20 gauge yellow, white and black,a nd if not black it will be ORANGE / black. Yellow is your (R-code) use a digital multi meter, measure the voltage between the (R-code) yellow and ground, ORANGE / black, then while the vehicle is running, cut your (R-code) wire, use a digital multimeter, measure the resistance on the key side, use resistors matching that resistance and solder them in on (R-code) wire yellow computer side of vehicle to ORANGE / black. Turn vehicle off, turn key to run position and let sit for 15 minutes, to learn new (R-code). Turn vehicle off, completely remove key, count to 10, reinsert key and start vehicle. Use digital multimeter, check voltage on (R-code) to ground, it should be the same as original reading. Good luck, hope this will work for you. crazy cooter

Well you can always use the normal way to bypass the system      You need 30 minutes of your time   (1) start the truck  let the key on for 10 minutes  (security light )  stop flashing Do this two more times  ( this is it )cocolaboy

jacqueslacombe's method works........but it is intended for the times when you install a replacement ignition switch, with a different resistor value from what was in the car originally........but if the existing ignition switch is simply broken, and putting out NO resistance, this won't do any good. But, his method should work out just fine if you did it like this: 1. Locate the PASSLock wires coming from the ignition switch: yellow (resistance), ORANGE / black (ground), and RED / white or maybe white(switched power). If you know what you're looking for, you can find them in the main steering-column harness, easily accessed by removing the large panel that's in front of your knees. If you're new to all of this, it might be easier to take the plastic shroud off the steering column, and find them right near the key cylinder. 2. Strip some insulation off the ORANGE / black, and cut the yellow in half. (Leave the switched-power wire as it is.) 3. Obtain a resistor that is similar in value to what GM might use on one of these cars-----I think anything in the 1000-2000 Ohm range would be a safe bet. 4. Connect the resistor between the ORANGE / black ground, and the BODY SIDE of the yellow wire that you had cut in half. (The KEY SIDE of the yellow will be left not connected to anything---tape it off if you wish.) (Make a careful, sure connection; if it fails, the car will be stranded.) 5. PROGRAMMING: This is what jacqueslacombe is telling you to do. A. Set parking brake, to disable automatic headlamps, so you won't drain the battery. B. Attempt to start the car. It should start for a moment, and die immediately, and the Security light should be flashing. Don't turn the key off---just leave it there in the Run position. After about 10 minutes, the Security light should stop flashing. Turn the key off. C. Repeat #B two more times. D. If all went well, your "new ignition switch" (which really is the resistor you connected) should now be "taught" to the car's BCM, and the engine should be allowed to start. NOTE: You have now permanently bypassed PASSLock, and anyone posessing the skill to break apart the keyswitch and turn on the ignition, will be able to steal the car. If the above method actually worked, you may want to go ahead and replace the ignition switch (the switch, NOT the lock; they're different parts), put the PASSLock wires back together, and re-program again. SECOND NOTE: All of this is working under the assumption that the ignition switch is the part that is at fault. It might be the car's wiring, the BCM, or other things. Just because you don't have remote start in there........did you buy the car used? It's possible a remote starter was in there before, and someone hastily removed it before trading the car in. I would drop the dash and at least see if there is any evidence of previous work.

Hello All, Thank You for all the advice, I tried the time delay for 30 minutes as stated, My security light never went off and stayed on, the truck still will not stay running, On monday i will try the bypass as you explained and will keep you posted. Rob.

Replace the ignition lock. If you are having problems with the Passlock then more than likely you need a new ignition lock.A little from column A, a little from column B.

bigac wrote: Replace the ignition lock. If you are having problems with the Passlock then more than likely you need a new ignition lock.

That's exactly what it is. First couple years for Passlock, the internals of the keyswitch were cheap plastic. The contacts that read the internal resistance value would wear out or break, leaving you with the same symptom as above.

You could use this procedure if your Passlock is messing up.  No need to add the remote starter.

PASSLOCK I or II DISABLEMENT

The following is a procedure to disable Passlock I or II Systems for vehicles in which remote start/stop system installations are required. This procedure is required because a remote start system will not function with the current Theft Deterrent System (Passlock) which is included on many  1996 and up GM vehicles.

Please note that this modification is intended to be used only in conjunction with the installation of a remote start/stop system and does not provide a procedure to install a remote start/stop system.

CAUSE

If an attempt is made to start a vehicle by a means other than a key rotation in the ignition switch, the Body Control Module (BCM) will interpret this start as a vehicle theft and disable the fuel injectors.

CORRECTION

A minor wiring modification may be made to allow the vehicle to be started remotely. This modification includes adding a switch to allow the customer to select “ON” to disable Passlock or “OFF” for normal Passlock operation.

CAUTION: When this modification is performed and the switch is set to the ON position, the theft deterrent feature will be disabled. When the theft

deterrent is disabled the SECURITY or THEFT telltale will light up indicating that the theft deterrent system is NOT functioning.

PASSLOCK MODIFICATION

Refer to appropriate GM service manuals and/or SVMQP Electrical Guideline Manual for instruction on splicing and electrical connections.1. Select a suitable on-off switch (see note below) which will be used to disable/enable the Passlock System. Mount the switch in a location such that it isaccessible to the driver and will not interfere with normal vehicle operation.NOTE: This is an extremely low current circuit (approx. 7mA), it is therefore very important that a high quality, low energy, fast acting switch be utilizedfor this application.2. Turn the ignition switch to the OFF position.3. Locate the Main Ignition Switch Harness. GM's Passlock System wires exit the Ignition Switch Tumbler together and then join with the Main Ignition Switch Harness.  (See   http://www.bulldogsecurity.com/ or  http://64.85.6.118/diagrams/diagrams.asp  and select your Make, Model and Year for wire colors and clues on the quickest way to access these wires.) 4. Locate the Yellow Passlock Data Wire which is included in a bundle of three tiny (20 GA) wires wrapped in friction tape.Cut this wire and splice a 0.5mm2 (20 GA) yellow wire to each end of the cut wire.Keep wire length to a minimum. Route modification wires clear of moving parts.Connect the yellow wires to the switch such that the contacts are OPEN when the switch is in the ON position.5. Turn modification switch to the OFF postion (contacts closed).6. Start vehicle to verify normal operation. If engine “cranks but will not start"recheck the switch position (contacts should be closed), wire connectors andmodification wiring.

SWITCH OPERATION

To enable remote start:

Start the engine with the ignition key (modification switch must be in the OFF

position). Turn modification switch to the ON position (contacts open). The

SECURITY or THEFT telltale will light up indicating that the Passlock System is inoperative.

Once the SECURITY or THEFT telltale has been on for at least 5 seconds the vehicle can be turned off and then remotely started.

To disable remote start:

The Passlock System can be reactivated by turning the modification switch OFF

(contacts closed). Vehicle can either be running or off when this is done.

Please note that the VCM/PCM will record Diagnostic Trouble Codes (DTCs) related to the security system when the modification switch is in the ON position (circuit open). This is due to the way that the VCM/PCM interprets this condition.

NOTICE

Any condition which removes battery power from the Vehicle Control Module/Powertrain Control Module (VCM/PCM) (e.g. dead battery, disconnected harness connectors, etc.) will prevent the vehicle from being restarted. If the engine exhibits a “cranks but will not start” symptom, place the modification switch in the OFF (contacts closed) position. This will reactivate the Passlock System and allow the vehicle to be started with the ignition key.

Ray