There have apparently been software updates available for my 1996 Dodge Caravan 3.0 L engine. Asking the local Dodge service center if I can just get the latest greatest update for this computer, the answer was only if there's a Technical Service Bulletin addressing a problem and it would cost $86 to analyze it (1 hour labor). Why not just let one pay for an update, whether there's a problem or otherwise? Or does one have to buy a whole new PCM with all the updates already flashed? I tried to explain too "a TSB seems to fit my problem" (see other post about stumbling after a restart on a heat-soaked engine). Still, bring it in for an analysis. So used to just flashing BIOS in desktop PCs. you'd think that request alone would be adequate. If I take it too them, how can I be sure it might really need a new computer instead of just a flash update? Thanks in Advance.

 

Further generic questioning. Is it OK to replace the PCM with a fully updated "new" PCM with all the software changes for one's vehicle? Reading through numerous problems with the Caravan and other vehicles, it looks like often the PCM is changed but while it might fix some things, new things appear as set codes. Is it that some software updates require changes in some hardware components or sensors to be done correctly?

 

Supposably the problem with the software should be fixed if your vehicle is made after that date. I have a hesitation on a heat soaked engine and there is a TSB if it was made before nov 97, but mine was made may 98. Same motor and everything. I'm still not sure what to do. I'm running techron throught it now. Maybe it's a carbon deposit issue.

 

Even with a new pcm you still need to ad vin and mileage. and skim key code if you have a skim module.

 

My problem was fixed with reference to TSB 18-12-98 dated March 20, 1998.
96-98 Caravan, 96-98 Voyager, 96-98 Town and Country, ALL 3.0 L engine.
Title "Tip-in sags/hesitations after hot soak restart". The symptoms included rough idle after 5 to 90 minutes hot soak restart. More prevalent in warmer ambient temps but clears up within 2 minutes. No DTC codes are set.

This was my problem exactly.

Per the TSB...
I replaced an Oxygen Sensor wire with a "jumper", a 6' length of wiring purchased
at the local Dodge dealer. I am not clear why replacing the original wire between the upstream O2 sensor and the PCM with this identically-looking wire, fixes the problem,
but it DID. I called Chrysler to find out the theory as to what was wrong and how the fix
works, but they would not discuss it with me, an end user. Said go to the dealer.

 

You mean the mileage and the VIN need to be programmed in?

What's skim key code?

Thanks

 

Yes they do. Skim module came after the VTSS ( Vehicle theft security system). and now we have a Skrem module, ( Sentry key remote entry module ).

 

For what it is worth, I visited the local Dodge dealership and they said they get no more information about the TSB than I had in hand and could not tell me anything more about how a replacement wire fixed the problem. Theorized only that perhaps there was a bad batch of wires in the original installation.

Whatever it was, when the engine was hot-soaked, for around 2 minutes after starting, the Caravan was nearly unusable, especially in the summer. It snorted, popped, sagged and could not be trusted to safely enter a thoroughfare. It always cleared up and that is why we lived with it. Still, it did not inspire confidence, not knowing why this was happening and why some shops couldn't ever find anything.

This episode might offer a strong incentive to take a vehicle to the dealership for they have access to all the sophisticated scanners but moreso, TSBs and service history. Can they be expected to do intensive searches? Or will they throw all the typical parts at it..."Tune Up" and the other things that cost, add up and would not have fixed this problem? The local Dodge shop had about 6 mechanics chime in when I visited and no one was familiar with this nebulous problem, that affected 96-98 models.