Probably the best course of action for the home-mechanic having trouble with glitched-up micros on his car is to substitute a known good and adequate battery. It's prob. a factor that the original battery size used in diesel GVs is a bit small for swinging a 2.8 litre 4-cyl diesel engine. Using two batteries with a battery isolator switch on the extra battery will result in much more enthusiastic cranking even in cold weather. (It's a shame that the only place to put it is in the passenger footwell).

My previous car was a diesel V-6 S-type Jaguar. When I acquired it at first, one of its problems was an intermittent (every few days) display of the MIL lamp (Malfunction Indicator Lamp) resulting in "restricted performance" when the car would drive like a slug. Every time I stopped for a few minutes to get some shopping etc.. the MIL lamp was out on start-up and and the car was back to its usual hairy self.
I had an idea the battery was a bit dodgy, and this was confirmed by others on the "Jaguar Enthusiasts Forum" of which I was a member. Strangely, the battery cranked the big engine no problem. A real problem was the daunting price to replace this enormous battery which wouldn't have disgraced a diesel wagon. So I simply wired a combo. of big electrolytic capacitors across it, costing me nothing as I already had loads of these in stock. This procedure completely stopped the MIL lamp from illuminating for the next three years. It never illuminated even once. I didn't think anything much about this cure as it was easy, much easier to fix than the other faults on the car. Ever tried replacing the ATF fluid on a car that has no filler, and no dipstick? I thought the man who designed it was a bit of a dipstick BTW. No problem like that on a GV.

Leedsman.

p.s. All the faults on my GV. have been down to lack of proper maintenance which is even outlined in the driver's handbook.
Fault one. Damaged radiator (aluminium core corrosion) due to not replacing the HOAT antifreeze within 5 years.
Fault two. Thermostat jammed open due to overheating due to fault one.
Fault three. Failure to crank and start due to unsuitable battery.

 

Thanks for the reply, Leedsman. Believe it or not, I just bought this 08 WB Chrysler edition shipped from New York, got it Friday, and had this. I just put a new battery in it Saturday. So that's when I did a search on the net for these Chrysler forums, and got my mind blown for what I've got myself into! After reading for the last 2 days of all the diff post about electrical problems, I'm stumped why our "great" government agencies allow this to go on, since several of them are there supposedly to protect us, of course for our own safety! So,o,o,o, that's why I was planning my route of attack. Done a lot of electronic trace work over the years, and many, many vehicle restores, repairs, wrote software packets years ago, (anyone remember the old C, C+, dos?) I think I'm pretty analytical? Well, at least in for a challenge! If I have to, I'll get it in the garage, and pull seats, carpet, trim, wiring harnesses 1 at a time. I do have some rusty mounts on the alternator, do you think their simple test at a close-by Autozone could tell me if its causing any problem? Thanks for any help, (Do you think I should start a new post on this?) dg

 

Ok Digg. Re. alternator. All of the battery TOTAL circuit should be examined for loosness, as even a millisecond poor connexion can result in a huge rise in alternator output. The boffins have measured this as being 60 or 70volt. This is why every auto electrician when in apprenticeship years is firmly told never to disconnect the battery when the engine is running. So it's not just making sure the battery post connexions are tight, the grounding bolt for the -ve lead, the engine ground strap, the alternator fastening bolts, the output terminal etc. etc. should be good and tight (but not cyl. head bolts tight -- remember it's only brass and copper connectors here).

You will guess the effect on microprocessor boards in the car if 60 or 70volt is suddenly applied to them, even for a millisecond. A millisecond is a long time for electronics.

But there is more: The alternator output is NOT STEADY DC. like a battery. The alternator produces three-phase AC basically. This AC is rectified by usually six diodes to a kind of "ripply" DC which is good enough for charging a lead-acid battery. But there is even more; because the output has to be controlled to an appropriate level of power, the charging current must be regulated. This is done by a sliding connector system onto the alternator's rotor which gets the control current to make the charge power appropriate. This is the slip-ring and brushes system. This sliding connexion can spark slightly, and these sparks can cause "spike glitches" onto the alternator output and therefore straight to the battery and onto any micro. connected. Some very latest ideas here get rid of the slip ring system and use a permanent magnet rotor, and instead control the output main current with power transistors and a switch-mode regulating system. No sparks here, no glitches.

Testing an alternator:
It's no good nowadays just checking that it's charging ok. You need to check the output with an oscilloscope, looking for hash and glitches AFTER seeing the connexions various in the total battery circuit are good. If the battery is poor due to sulphation, hash and glitches will be "allowed" to ride on top of the 12volt supply from the battery. The 'scope shows this effect quite clearly. It also shows how the hash/glitch situation is markedly reduced if a second good battery is connected with jump leads while running. The hash/glitch situation is also reduced if a VERY large capacitor is connected across the battery/alternator. I've done this myself and posted pictures here. I had to use a digital 'scope as the camera I used was too fast to display a CRT 'scope properly. Suffice it to say, if you can keep the hash/glitch situation down to a few milivolts, you'll be ok.

If you wish, I can continue this tutorial or explain anything confusing.
I don't blame Chrysler particularly for micro. problems in their cars (see Chrysler's request for appropriate information on this website) many other makers have micro/glitch problems, and not just car makers.

Leedsman.

 

Too true. I sold a BMW 645 in September after owning it for only 6 months. 4.4 V8, 340 BHP and 160 MPH but it cost me £1,000 to fix oil leaks and electronic glitches. One of the problems was the nearside dipped beam failed while we were driving in Spain. It's a known problem but stealers in the UK quoted £1,400 to fix it !!!

 

OK Leedsman, I follow you there. Took Electro-Mechanical Engineering back in the 70's, (I know a lots changed since then!) Done a lot of computer building and repair for years. Not so much these last couple years with raising 3 grandkids! OK, I've done a lot of electrical work, worked on some generators that use these same slip rings, so I do follow you on how we're getting our voltage from much more than the old alternators. What do you think of unplugging the door wiring harness first? Would that maybe not do any good with the possible ghost voltages, due to feedback in the wiring? I'm also thinking of the steps I mentioned earlier in that order, of course tap on dash for maybe a loose connection on the instrument cluster, working (by wiggling) the readily available wiring harnesses-sliding doors-drivers front door-ECM up front for possibly broken wiresbattery connections, ground connections, pull the ECM module, up underneath the drivers front wheel, and check plug & connector for dirt and corrosion, I don't know if there's a Chrysler dealer of any size that probably has a oscilloscope withing 80 miles. I'll put a new alternator on it if it comes to trying that! Was I flustered when I picked it up in town and drove 2 miles home with everything flashing like that! And to think I bought it after looking at a video on-line, and reading a description the owner had of it, I did talk to him several times, but oh well, in it for the long haul now!!!!! I'll fix it, it will either be EASY or HARRRRRD! Thanks for your replies!

 

Ok Dlgg7.
The first thing I would do is to connect a second known-to-be-good battery with jumper leads or whatever, so you may start and drive with it connected. Then you can see if the fault(s) are still there or not. If the faults have disappeared the remedy is obvious. (The "new" battery you fitted may not be as 'new' as you thought. Often batteries sit so long unsold on the dealer's shelf they become sulphated). That is of course after first establishing that all relevant battery connexions as outlined above are good. Before performing the 2nd battery test, remove possible stored glitches in all the micros by disconnecting the main battery -ve for a few minutes. This does the hard-reset. Do not then start the car until you've re-connected the main battery and connected the second battery, carefully observing polarity. Thusly you should be commencing with "clean" micros and TWO batteries for the test.

Second thing,
See if you know anyone who's a bit of a radio "ham" or electronics experimenter. There is a possibility he has a 'scope, and will connect it across your battery while engine is running. This will be a very simple job for him. He will advise you on glitches sitting on top of the 12volt supply. If the hash/glitch is bad, I suppose a new or at least reconditioned alternator is indicated.*

Third thing,
Your mention of corrosion in connectors various pertains strongly. If you can find ALL these connectors, cleaning with some "Electrolube" (that's the best) and unplugging and plugging a good few times will fix. Don't forget all the micro. boards will be in communication with each other via a bus of some kind. Very subtle corrosion on one of these connectors in the data-bus system will cause TIMING ERRORS in those very data themselves, probably leading to malfunctions. Remember just about everything in a car now is actually micro. controlled, the driver merely sends a demand for the the micro. to carry it out, whether it be for a light to be switched on, a door to be opened, or a driver's foot demand for more power. Keep an eye out for any connector that looks if it might be slightly corroded, or it lives in a damp-ish area, or a hot area. It seems the "body module" or the one with all the fuses can be corrosion-suspect according to Qinteq. On mine it lives right next to the battery in a hot area under the bonnet. Even so-called 'sealed' lead-acid batteries aren't actually sealed. There is always a "venting" system in place, and the fumes can cause corrosion after a time. Especially if a micro. board is right next to it... Oh to be back in the 1970s when there was none of this!

Leedsman.
* Only older contributors will remember that alternators with rectifiers wern't used at all in cars for charging the battery before the 1960s. Instead a "dynamo" or DC generator with the rotating commutator and brushes in the main output current windings. There were no semiconductor diodes then, and when idling at night in stalled traffic, the battery could steadily run down because there was insufficient dynamo out put to charge the battery at engine idle. Result? Brown-outs, no heater fan, no radio, and girl-friend complaining she was bored and cold. Hence the "choke" pull-**** had a "fast-idle" part so the battery WOULD stay in charged condition.

 

Dodge Caravan electrical issues.

These vans are known for having weird electrical issues. Some are caused by corrosion in the Integrated Power Module under the hood, others are caused by a shorted module on the high speed data bus, and still other are caused by good old corrosion on the ground connections. If your van has crazy electrical problems like interior lights that flash, or power door locks that open by themselves, or the rear wiper suddenly starts working even though the switch is in the off position, you may have a toasted body control module (BCM).

Why do I think that?

Unlike in the old days where switches actually turned power on and off to each accessories, switches in newer vehicles just acts as a signal to the BCM. The BCM either switches power or sends a data signal to the Integrated Power Module or Totally Integrated Power Module and the power switching is done there by the front power module (FPM). Given the corrosion problems in the IPM, TIPM, or FPM, you could easily assume they’re at fault. And they may be. But the commands come from the BCM, so you should always start there. And the first test is for good power and grounds for the BCM. You must test for good ground under load.

And a common culprit is the ground point located at the base of the B pillar. That’s the one on the passenger side between the front door and the sliding door. Don’t know how to test it under load? No problem. Just remove the plastic trim. Located the ground screw. Remove it and clean the corrosion. Then lightly coat the newly cleaned metal with dielectric grease. Then reconnect the ground and see if the problem goes away. In many cases, that solves the problem. If it doesn’t, head for the IPM, TIPM, or FPM.

Full list here.

For myself I've always thought that the IPM / BUS is a big issue .. .. every signal and sensor passes through this six layer[ed] bit of PCB, its only once you pull off the connectors from the bottom of the IPM and undo the 4 clips that separate the layers of the IPM you begin to see the corrosion. The IPM at first sight can look bright & beautiful, inside can lurk a very rusted ugly duckling.

 

I have a very similar problem in my 2007 T & C. Started a week ago. I went to drive the vehicle and I noticed the key wouldn't open the electronic door lock. Got in started the car and it wouldn't stay running just shut off. I did this three X's no luck. Thought it might be a dead battery. Went to jump it took an hr. to find my cables and get another car to use. Got back on a hunch tried to start it again. It started right up and ran. Now however the cluster went crazy with gauges on and off trouble lights on and off. Passenger air bag light on and off etc. Took to my mechanic. He tested got error code pointing at the cluster array. But, noticed if he tapped on the IPM it worked. When he tested it the windshield wipers also wouldn't work. He told me to take it to a dealer to look at and didn't even charge me. he seemed happy for it to go away. Took to a Dodge dealer nearby. They had it 4 days ran it through all kinds of tests found some codes but when reset they didn't appear again. They took out the cluster and bench tested it. $350 later no error codes and it ran. They were stumped. Now I have essentially a mystery and a car that is unreliable to drive.

 

Small project update, if you will.

I got fed up with the "flashing" or flickering console and instrument cluster lights, because the other side effect was premature bulb failures in the interior lights. I'm talking about the instrument cluster and all the other center console and overhead console backlights inside the car. So I went down to the local electronics store and got two 10000 uF capacitors, in-wire fuse socket and a fuse of course. The capacitors could have maybe been a bit bigger, but the guy in the store said these would do the trick. So I went to my workshop, wired the capacitors across the battery terminals and so far I haven't observed any flashing in the backlights anymore. Now it's just a matter of time to be able to tell whether or not that fixed also the problem of the bulbs burning out prematurely. My personal guess is it will help that too, because "spiky electricity" is pretty much the only reason I can think of causing the bulb problems.

edit:
How can I tell the lights flicker? Well, in Finland the days are getting darker and the flickering has been very clearly visible when it's dark and the interior lights are switched on. Now the only place where I can observe (very) minor flickering is the odometer LCD as well as the shifter position LCD in the instrument cluster. That flicker can also be caused by the refresh rate of the LCD, so I'm not too concerned about that.

Thank you Leedsman for your advice and documentation! It has proved very helpful so far. Keep up the good work!

I'll get back here later on with a report about the console lights, whether they are still burning out in abt 1,5 yrs or so. I think they should last longer than that and now that I have 7 bulbs in the instrument cluster which are a bit above that age, I would expect them start failing during the next 6 Months or so. One of the eight bulbs already failed which was the trigger for me to get the capacitors. I had replaced all the bulbs at the same time about 1,5 years ago so in case the power supply to them remains spiky despite the de-glitcher, the rest should be failing in the near future too.

 

"Thank you Leedsman for your advice and documentation! It has proved very helpful so far. Keep up the good work! "

One appreciates this kind of feedback...

Another factor in this that came to light recently was the business of slightly corroded battery connexions themselves, there are some recent postings on this one. After a time, these connexions can act like a bad rectifier, and allow glitches onto the 12volt line. Curiously, this slight corrosion doesn't affect the starter motor much. It's a simple enough remedy, just clean off the corrosion, apply a little grease and re-fix.
Speaking electrically, because the alternator's rectified output is a bit "lumpy" and can have glitches on it, the whole system relies on the battery to "hold-down" the alternator's output to a smooth dc. If you have flickering lights, and esp. lamp-bulb failure due to over-volting (vehicle lamps are designed to operate on 14.4volt for a reasonable life) there could be a poor connexion somewhere in the main battery circuit...It could even be internal to the battery. Lead-acids have been known to corrode internally. Hence strapping another battery to the system on top of the vehicle's battery helps establish what's happening while engine and alternator are running. Also ensure ALL the heavy-current wiring in the battery/starter circuit is good, ALL the bolted ground chassis connexions (the chassis is part of the -ve ground return to the battery).
Re. a large capacitor across the battery. I use a combo totalling 100,000 microfarads, but nowadays much bigger capacitors around one farad are available -- at a price. Wiring a second battery across the existing one will have much the same effect by holding down any fluctuation/glitches from the alternator.

Leedsman.