98 Silverado Starting Problem

[Jessefjr]

Re: 98 Silverado Starting Problem
OK, I found the old diagram that I worked from. Here is the permanent bypass procedure on the security wire.

Try this when truck goes into "tamper mode". It will start then immediately die. Wait five or ten minutes, and then it will start right up. Of course, confirm that your vehicle has appropriate Passlock as noted in posts above before doing this!!!

Here's a diagram showing what I did. You need to take off the lower dash panel to get at the wires.



I cut the yellow wire, then measured the cranking ohms resistance at 577. Then off to Radio Shack, where they had 560 ohm resistors +/- 5%. I bought a pack of five for 99 cents. I measured the resistors to find the best one. Closest I could get (to 577) was 554 ohms, so I soldered that one onto the yellow wire (processer end) and into the orange/black wire.

The full instructions said I needed to be within 1% to 2% on the ohms. I was more like 4% off the 577 ohms, but the truck fired right up with no problem.

That was over 8 years ago and the truck has worked perfectly ever since I soldered in the resistor. I fixed the problem for about two dollars in parts!

Let me know if this helps at all.................

Dave in RI


Hi, I'm having the sam problem and trying to do the resistor fix but having trouble with getting the correct ohms. I'm using a sperry dm-210a digital multimeter but I'm not getting close to the 577 reading that you had. With my truck running there is a symbol that looks like a speaker and I went through the different settings and this is what I have Spkr symbol 817 at 20k 6.04 on the 200k 05.9 and 2m .003 am I doing something wrong or have the wrong equipment?

Thanks

[gremlin96]

you need 817 ohms resistor. if you read the manual to your digital multimeter you will find there is no speaker on the display. what you are seeing is ohms.

[Jessefjr]

Ok and Thanks. I'm giong to try this today.

[Jessefjr]

Well it looks like my local Radio Shack only have resistors up to 620 ohms on hand so it looks like I may have to order some online.

[gremlin96]

817-620=197 all you need to do is buy two. solder the end to end and put some shrink wrap over both of them. you will need to get one that is 197 ohms. you must remember radio shack sells only 10% tolerances so you will need to play around a bit, to get a match. i would get a pack of 200 ohms and a pack of 620

__^^^^__^^^^___
620 + 200 = 820

[Jessefjr]

Ok, I hooked this up this morning and it didn't work. It's doing the same as before. Any ideas?

[gremlin96]

do you have close to 817 ohms. or very close to it. did you check to see that you have good connections.

[Jessefjr]

Well since I wasn't sure if the $10 meter I was using had givin me a correct reading I borrowed my brothers fluke meter and rechecked it. 597 is the reading I got so I went with that instead of the 817 that mine showed. I still had to use 2 like you suggested and wound up with 592 which is the closest I could get. I checked all of the resistors with both meters and got the same readings with the exception mine would show 592 and his would be 592.3 maybe I should have went with the first reading off the cheap meter??? Well I cut everything loose and after about an hour and several start attempts I'm running again and back to square one.

[gremlin96]

use the fluke and check the first reading to see what rester you need. then using the fluke meeter match the resistors.

[Jessefjr]

hey since my last post i had read in a thread somewhere about the pjlx xpresskit interface so i ordered 1 to try because i was out of ideas. well after installation everything seemed to be working well for about 3 weeks now up until yesterday, then guess what... yep, it happened again. this morning after finally getting it started again i checked the resistance again with the origianl meter and came up with 830 ohms. i figured since i had tried the 592 i would go with the other. so off to radio shack and picked up some 560 to use with the 270 i already had. i came up with a total of 818.3. i did a sort of temporary install till i can get the soldering iron back from my brother and so far it started with no problems. my security light is on but if my problem is fixed that will be minor. only time will tell.

[ponchonutty]

Originally Posted by Jessefjr

hey since my last post i had read in a thread somewhere about the pjlx xpresskit interface so i ordered 1 to try because i was out of ideas. well after installation everything seemed to be working well for about 3 weeks now up until yesterday, then guess what... yep, it happened again. this morning after finally getting it started again i checked the resistance again with the origianl meter and came up with 830 ohms. i figured since i had tried the 592 i would go with the other. so off to radio shack and picked up some 560 to use with the 270 i already had. i came up with a total of 818.3. i did a sort of temporary install till i can get the soldering iron back from my brother and so far it started with no problems. my security light is on but if my problem is fixed that will be minor. only time will tell.

If that light is on then you are OK until the battery goes bad or you unhook the battery. It's in the "fail/enable" mode which it knows there is a problem but it will allow you to drive. Once it forgets (like battery unhooked) then it won't start.

The best thing to do is get something like 1500 ohm resistor and wire it up on the BCM side of the cut yellow wire and the other to the orange/black wire and then tie that to a chassis ground.

Try to start. It should start then die out and the light flashing. Leave the ignition on for 10 minutes or until that light goes out. Shut ignition off, count to 3 then try to start it. It should start. If it doesn't, leave the ignition on for another 10 minutes or until the light goes out. This could go on for up to 3 tries.

If for some reason it won't learn, cut that value in half and try again. Once it learns, it will never fail again. I've done over 100 GM vehicles like this.