Well that just take all the fun out of it!
Think I'll wait for it to happen again,
Put some Break Free CLP on the key,
Fiddle a bit, and see if that helps.

 

Have to agree with Raptor7, sounds like a TIPM (totally integrated power module) may be ready to fail.

All of the electrical current distributed throughout this vehicle is directed through the standard equipment Totally Integrated Power Module (TIPM). The molded plastic TIPM housing is located on the left side of the engine compartment. The TIPM housing has a molded plastic cover. The TIPM cover is easily removed for service access and has a convenient fuse layout label affixed to the inside surface of the cover to ensure proper component identification.


The TIPM housing is secured to the TIPM mounting bracket by four clips integral to the TIPM housing. All of the TIPM outputs are through the integral engine compartment wire harness.

All of the current to the Totally Integrated Power Module (TIPM) comes directly from the positive battery cable to a stud located on the bottom of the TIPM. The cable is secured to the TIPM stud with a nut. Internal connection of all the TIPM circuits is accomplished by an intricate network of hard wiring and bus bars.

 

I has a look > under < my IPM [2005] many months ago, and a few places needed cleaning, just two or three were very dirty connections. This is from the Jeep forum, but you can see from the diligent work of the poster that its more than just the fusebox people think it is.

 

Hi, I am a litigation assistant at Girard Gibbs. We are investigating consumer complaints of electrical problems in certain Chrysler vehicles, including Jeep Grand Cherokees, Jeep Wranglers, Jeep Liberties, Chrysler Town and Country, and other models. If you are interested in assisting our investigation or sharing your experience with us, please email emo@girardgibbs.com, call (866-981-4800), or visit our website Chrysler Lawsuit Investigation

 

In the past I have encountered this wierd and unexplained "microprocessor-madness" not just with cars but with other microprocessor-controlled machinery. Indeed, so have aircraft manufacturers and other car makers.(E.g. Toyota and their accelerator problems).

Rcrosby, you unconsiously put your finger on it when your title said "glitch". The fact no relevant ercos appear from the micros error memory also is a clue.

I'm prepared to help here if possible, but I don't want any sarcastic and unhelpful comments from any other contributors to this thread. If this happens again I will exit from it. Sourcing this type of fault is far from easy.

Leedsman.

 

Often, those mysterious doings of various microprocessors that don't seem to make sense in cars and other machinery have been upset by "glitches".

Often, errorcodes are shown which bear no resemblance to an obvious fault, or the fault comes and goes capriciously, or is affected by the weather, partic. temperature. Or even no errorcodes at all.

Often, even manufacturers have big trouble sourcing the microprocessor problem(s) as is shown on this very thread by a poster trying to acquire data for legal reasons maybe.

In a car or other vehicle which is controlled by microprocessors various, glitches can be created by the alternator or the starter motor commonly, or other devices less commonly. The alternator has slip-rings carrying a current of a few amps which can spark, the starter motor has a commutator and brushes carry a current of hundreds of amps which can spark a lot. At the same time, the starter motor drags the battery voltage down to around 9volt., making microprocessors much more liable to be affected. Sparks radiate and conduct their glitches everywhere. Sparks are bad news for micros.

At the same time, the battery can resonate at a similar frequency created by power-glitches in the 2 to 6MHz band. This can affect the numerous clocks in the micros, many of which are derived from a master clock and then put through a divide by "n" chip to give other frequencies. One of the microprocessor boards in GVs is right next to the battery. I believe it's called 'the body module'. (Quinteq mentions examining the underside of this fuseboard for corrosion -- that's a very good idea).

Many manufacturers wire in electrolytic capacitors in the wiring loom to arrest the glitches, and are not always shown on service manuals. These type of capacitors have a finite service life of anywhere between 1000hours and 5000hours -- they just dry out over time and heat. I found Panasonic had a long life.

Rather than sweat trying to locate and replace these capacitors, it's a lot easier to simply wire one across the battery (with the essential safety fuse in the + lead). I have included a picture of my Mk. I version. I had to use two times 15,000 microfarad, as I didn't have any singles. So it's 30,000 microfarads in tot.

As it's hard to prove anything with glitches etc. this is a purely "suck it and see" excercise. No guarantees. If it don't work, it's prob. wasn't glitches. If it does, it was.

Leedsman.
Hope the pix. gets there.

 

Dude u have got to give up on that wiring in a capacitor to the battery stuff its not going to work.
If u add stuff like that to a car I can promise u there will be more then enough issues that you will create then solve.

 

You just can't leave it alone can you?

Leedsman.

 

I was going to say the same thing

 

- there's a thin line between helpful moderation and free speech and the suffocating of someone else's point of interest
- this is bordering on someone wearing a moderator title apparently stifling free speech
- you don't have to agree with Leedsman, and have severally said so, but surely he is allowed to post an opinion on these boards
- the most successful and popular forums from the days of DOS BBS to current vBulletin all share the same light 'light handed' moderation

You two should kiss and make up, and allow all opinions to have the oxygen they deserve, only by shining a light on a problem or an opinion do we find solutions .. .. which is after all why we are here in this place.