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Feel like an idiot

Steve #1

Steve #1

Well-Known Member
Messages
534
Location
TEXAS
You are correct that the resistor is not part of the key on the H3 (it is on GM keys with the little black "chip"). Diferent ignition switches have diferent resistors which is why you must measure the resistance of your switch (when it is working).

Cut the WHT/YEL wire. Connect a multi meter to the key side of the wire and probe the WHT/BLU wire with the other lead of your meter. Turn the key to start and hold it to determin the resistance of the switch. You will then need a resistor with this value which you will connect between the WHT/BLU wire and the cut WHT/YEL wire away from the switch.

This should work. If it trips the security light and won't start (assuming you used the correct resistor) this is because the bcm is constantly seeing the resistance on this wire (again, I'm not sure if the H3 watches it at all times or not) and you will need to add a relay so it is only in the loop when the key is in the start position.

With that said, there may be an even better solution which would be to remove the ignition switch and spray the contacts with electrical contact cleaner. A bit of gunk on the contacts could be throwing off the resistance the BCM is seeing from the switch.

BTW: Using a bypass sold for a remote start system will be doing the same thing as what my method does. You just get it in a box and it costs more. It will take care of the relays if that part is needed.
 
deserth3

deserth3

Well-Known Member
Messages
1,077
Location
Conroe, TX
Look at the schematis in my previous post. Our ignition switch has a restistor built into the switch at the start position. When you turn the switch to start the computer checks for this resistor before starting the engine.
Steve#1 may be correct that taking some electrical contact cleaner and spraying the contacts inside the switch may correct the problem. There's no reason why the resistor should burn out. Unless you have an electrical spike. In which case it should burn up your computer too.

Electricaly, our system should care less what key is inserted into the ignition. The lock tumblers take care of that. Our system only detects the switches removal and someon tries to start the truck. i.e. someone breaks in and removes the switch with a slide hammer.

Things that could fowl up this system...
1. bad or corroded contats
2. Bad or corroded swiitch connectors.
3. Damaged wire either between switch and computer or between switch and ground
4. Bad ground connection.

Unless you've been messing with the wiring under your dash. The most likely problem is the contacts in the switch.
 
deserth3

deserth3

Well-Known Member
Messages
1,077
Location
Conroe, TX
Yes
I've haven't done it personally and I don't remember the key type number. The original posts about our keys has been lost in forums past.
But going to a key shop is usual a lot cheaper than going to the dealer.
 
telemike

telemike

Hummer Enthusiast
Messages
466
Location
Greensboro, NC
I hate this security system.

Contacted pcmforless and think I will drive down there and get it taken care of for good and get some performance too
 
Last edited:
bebe

bebe

Moderator
Messages
1,375
Location
Dayton, NV
That's a great find.

I didn't take the time to read the whole thread, but how is the insurance company going to feel if the theft system is disabled? DO we get rate reductions based on Passlock?
 
bebe

bebe

Moderator
Messages
1,375
Location
Dayton, NV
When it starts happening more frequently - it's time to get it fixed. From what I have read it gets to the point where it never relearns and you are just done.
 
ReconH3

ReconH3

Guardian Angel
Messages
2,288
Location
Raleigh, NC
Awesome. See if they can also turn off the daytime running lights and tire pressure monitoring system.



Ex Umbris Venimus
 
ReconH3

ReconH3

Guardian Angel
Messages
2,288
Location
Raleigh, NC
Could you please ask anyways? I asked in an email but they never replied. Maybe for legal reasons. TIA



Ex Umbris Venimus
 
telemike

telemike

Hummer Enthusiast
Messages
466
Location
Greensboro, NC
Will do. Appointment on Monday. Darn this cold weather. I need to change belt and tensioner and I don't have a garage

Sent from my LS670 using Tapatalk 2
 
bebe

bebe

Moderator
Messages
1,375
Location
Dayton, NV
telemike said:
Will do. Appointment on Monday. Darn this cold weather. I need to change belt and tensioner and I don't have a garage

Sent from my LS670 using Tapatalk 2
Click to expand...

My Tuner said it was a part of the BCM - good luck at the appointment. Keep us posted!
 
telemike

telemike

Hummer Enthusiast
Messages
466
Location
Greensboro, NC
I hope PCMforless is right about the Passkey. My wife will kill me if it turns out they cannot. I may see if I can have the TPMS threshold lowered as well.
 
shawndondo

shawndondo

Zombie Slayer
Messages
49
Location
Enterprise, AL
please let us know if PCMforless can disable the passkey. I might have to make a call to them if they can. No issues yet but i dont want to get stranded somewhere.
 
Steve #1

Steve #1

Well-Known Member
Messages
534
Location
TEXAS
telemike, Would you be willing to try cleaning the ignition switch? The more I think about it, dirty contacts on the switch are the most likely problem. Unless i'm thinking about one of my other trucks (which I could be) there is a hole in the bottom of the steering column cover. If you stick a screwdriver in the hole and push up you can turn the key to "on" and the switch will pull out. If im wrong, you take screws out from the bottom and remove the cover and can then find either a set screw or a pin to depress that will let you pull the switch out (again, turn the key to "on"). Spray a little electrical contact cleaner on the contacts and see if you have any more problems. If you have the cleaner, the rest of the process shouldn't take more than 5 minuets
 
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