Kleasmith

I have a '99 Grand Cherokee Laredo, 4.0 v6. Parked it one day. It sat the next. Day after that tried to start it and it cranked over and over, but would never start. Gauges are dead, security key light is on. I'll admit, I'm a girl and don't know anything. I've researched till I'm blue in the face. Everything says it's anti-theft telling it not to start. Humans keep telling me fuel pump, even though I tell them about code. Can't afford to have it towed until I have an idea what it is. Man came and looked, said he listened to me, checked everything I did, said he tested fuel pump away from computer and it was bad. I went ahead and bought one. Tested before put in and works. Doesn't work after put in. Same situation. I don't feel as dumb. Now he is telling me I need to get my key reprogrammed, but I have 2 and neither work. Would it be the key? Do I need to reset it a different way or do I need to break down and tow it to the dealer? Single mom with mechanical ability but no automotive skills. Direct me and I'll do it. Please, no judgement. This is how I have to do things. Thank you

bigblue91601

If it’s like the zj and it’s possibly the anti theft, on my jeep I have to unlock it with the key from the front passenger side, that usually disables the anti theft in my old Jeep, worth a shot 🤷‍♂️

Kleasmith

I believe that is what it is. I will definitely try it. Thanks so much!

Kleasmith

I just went out and tried it, and lucky me....wouldn't you know, there is no key hole on the passenger side! I've also seen where people have done this with the back hatch....no key hole back there either! 🤯

bigblue91601

Give this a try

https://itstillruns.com/reset-grand-...t-7492453.html

dave1123

Try this also. The gauges being dead tells me there's low voltage in the battery or in the wiring harness going to the control circuits. Disconnect the battery and fully charge it. It should read 12.5 to 12.7 when fully charged. By this time, the computer should have lost it's memory so you don't have to clear it. Inspect the battery cables where the red wires come out of the clamps for corrosion. Very often they corrode without being seen easily. Connect the battery with all the doors closed. Open the driver's door and the interior lights should come on. That tells you the body control module has power and is functioning. Insert the key and turn it on without starting it. If all the gauges come on and the SKIM light is out, you're good to go. (SKIM= Security Key Identification Module) If the SKIM is still on, close the door and cycle the lock/immobilizing circuit with the key fob. If no key fob, lock and unlock the door with the key. When locking it with the fob, the parking lights should flash once and the horn will beep once. When unlocking, the parking lights should blink twice with no horn.

If the SKIM is still lit, it will have to be reprogrammed by a dealer. Each key transmits it's own code which the SKIM module holds in it's memory. It can hold as many as 10 codes. The keys do not contain a battery and transmit a code when activated by the transmitter ring around the lock tumbler in the column. The car comes with 2 original keys which are brown or grey plastic covered. All aftermarket keys are black. If you only have black keys, therein lies your problem. The SKIM doesn't recognize them. A dealer can program the SKIM for your keys or you can buy a new SKIM with 2 keys for an unreasonable price! Consider the towing fees to take your jeep to the dealer and the price of a new SKIM doesn't seem so unreasonable.

There is another alternative. You can get your computer reprogrammed to not need a SKIM. It will still look for it and set a SKIM light, but you can still drive it. At this point, you may want to inspect the computer itself. I had this exact problem with my 2000 after sitting for a year and the computer was corroded in it's mountings and leaking silicone. Time for a new one.

amxlonnie

I had a similar problem with a 1996 cherokee. suddenly wouldn't start and all gauges didn't work. scan tool wouldn't read anything either. it wound up being a crank sensor grounding out the 5v sensor feed and that basicly killed everything. I found it by checking basics. looked for 5v at the TPS and it was dead. after unplugging the crank sensor gauges started working and scan tool worked. you might want to check for a 5v feed voltage- ANY SENSOR can short out and kill this voltage which is critical for vehicle functions.

dave1123

Quite often the wiring harness gets abraded behind the head where it crosses over to the other side or gets oil soaked and shorts out. The 5v supply is critical because without to, the PCM doesn't get a signal.