Tj jeep stalling aproxx 10 sec after start please help

[FARWEST]

Im liking your thinking and explanation....havnt tried starting the wifes toyota without the fob being on the key ring...not that it should make any difference when the fob is door locks only...thanks for the info....all makes sense...now

[layback40]

Originally Posted by bonza

I also have a 79 series land cruiser that uses the same system. a sentry key that has a chip and a completely separate fob with a battery to send a signal to open/close door locks

the chip in the key has a unique code that receives a a radio frequency signal from the sentry key immobiliser module (skim) that is adjacent to the ignition switch and has a round antenna wrapped around the key barrel. when the skim reads the key and verifies the code it in turn ok's the pcm to allow engine ignition. the whole system is called sentry key immobilizer system (skis)

the electrical power is in the skim, not the key. just like antennas do not need power to receive signals.

keys with batteries have the ability to do other things, like open doors, whereas my cruiser like the jeep has a key with just a chip, but a separate fob with battery for powering door locks

I think you find those you tube clips about replacing key fob batteries are those type of keys for remotely closing and opening door locks as well. nor powered door locks on a TJ

to the op, does the the skis warning light stay illuminated? a scan tool should detect any skis related dtc's. if not I'd be tracing earth faults

I'm an engineer, but not electrical and certainly no expert so am happy to stand corrected

I to am a professional engineer, 35 years since graduation.
My 98 XJ has a chip in the key (no battery) & a fob with a battery. Sometimes it needs the fob to be pressed before the jeep will run. The previous owner had a spare button (more like a squashed button) battery in the console just in case. You can use the key to open it & start, just sometimes you need to press the fob before starting. I have never seen a fob from that time without a battery for a jeep. Seeing the fob in a pic would soon resolve things.

[bonza]

below is my 2016 Land Cruiser immobilizer key and fob. no battery in the key, just a chip. but a battery is in the fob which is designed to be taken apart for battery replacement as per details in owners hand book. the fob is a bulky thing and I just drive around without it as it makes no difference to starting the engine. I use the key the old fashioned way for opening the door locks.



below is the TJ immobilizer key, just a chip and with no door unlocking fob with a battery as the door locks are manual. try prising this open looking for a non existent battery will stuff the chip and lead to a world of woe



many other vehicle brands, and it would seem other Jeep models, have the immobilizer key and fob combined in the one unit, because they have powered door locks, which does require occasional battery replacement

[layback40]

Originally Posted by bonza

below is my 2016 Land Cruiser immobilizer key and fob. no battery in the key, just a chip. but a battery is in the fob which is designed to be taken apart for battery replacement as per details in owners hand book. the fob is a bulky thing and I just drive around without it as it makes no difference to starting the engine. I use the key the old fashioned way for opening the door locks.
immobilizer key, just a chip and with no door unlocking fob with a batterdoor locks are manual. try prising this open looking for a non existent battery will stuff the chip and lead to a world of woe



many other vehicle brands, and it would seem other Jeep models, have the immobilizer key and fob combined in the one unit, because they have powered door locks, which does require occasional battery replacement

Yes, there are many keys fitted with such a chip. Its not actually a chip. Its a RF tuned device that the receiver sends a signal to & can detect its presence. Because its passive, it doesnt need a power supply.
There are many applications for this technology, including livestock identification tags & the security tags on some goods in shops.
Again, I may be wrong, but didnt the OP say fob?
Fobs, like the one on the right in your pic have batteries. When you push the button they send a signal. My XJ's have both fobs & keys similar to your pics & KJ's have a combined key & fob, that has both the passive device & the active device requiring a battery. Such technology is normally covered in a 3rd year subject of an engineering degree, assuming you are a professional engineer & not a tradesman.

[bonza]

the op said fob maybe as a colloquial I guess, and he is discussing a problem with an '05 TJ same model as mine, which has a sentry key with no battery, but a "chip" for want of a better word. they only have door locks that are unlocked/locked by sticking the key in the door old style, no electric locks

never did cover such tech in my third year of engineering and for the record I am a professional and qualified mechanical engineer who also has a fitting and machining trade certificate and recently retired after a long 50 year career working for a big australian company

I don't like your insinuation about my qualification from someone over the internet I don't now from a bar of soap, and besides what's wrong with tradesmen? many are more competent than so called professional engineers

there's nothing else I wish to contribute here so over and out