hi guys ,I have a 2008 Dodge Grand Caravan CV -3.3L - 120 000 miles - it showed P0201,P0202,P0203,P0204,P0205,P0206 - all 6 injector codes simultaneously . Changed the (ECP,PCM) with a "new" reprogrammed one . New ECM run absolutely perfect for 5 minutes , then all 6 codes showed again .....Changed with another new ECM - that ran fine for a week , before lighting red immobilizer light - imposible to start vehicle. I put another "new" reprogrammed ECM - shows the same 6 codes again . Ughhhhh.
I had new injectors put in before that - they ran fine for 5-6 months.

...with last ECM later codes U3002 (network) and P04F0 (powertrain) appeared .....none of them are listed in the "alldata" database for this model , looked online ....no luck ..... :-(

 

1) Unless there’s other details you’re not sharing, you probably didn’t have to replace the PCM at all, let alone 3 times. Same goes for the injectors.

2) The codes u3002 and p04f0 - were these typos? I can guess by your note about the network that you may have actually meant u1002, but the P04f0 isn’t a valid code. It’s possible the code reader you’re using isn’t capable of reading a Dodge specific code.

That said, if it starts with P04 then it refers to the emissions systems which is unlikely to cause the issues you’re describing.

3) Try swapping the auto shutdown (ASD) relay with another relay of the same style - the AC clutch, headlamp, or horn relays would be good ones to try.

Try also checking the 2 large connectors near the throttle body for corrosion. These connectors are known to have problems with water intrusion and causing problems.

4) You’re gonna have to get a test light or multimeter and start DIAGNOSING the problem. If you’re not comfortable with diagnosis, then you’re better off towing it to a shop - you can at least have them diagnose it for you, if not repair it, and the diagnosis will cost you far less than the money you’ve already spent on PCM’s.

 

Before i changed the ECM i checked all cables.
All 6 injectors had baterry voltage and no shorts to ground or positive.
Checked all 6 signal wires for short tp ground or positive.
Checked all 6 signal wires for continuity to the corresponding pins on the orange ECM connector. - all wires had the same resistance.
all 6 injectors have the same resistance.

......i assumed wires were fine.....😕😕😕😕😕

 

Sorry for the delayed response - I didn’t see you had responded.

What were the resistance readings? Will a test light grounded at the battery turn on at the injector connectors? I’d have to look up the injector specs, but the wiring shouldn’t have more than 0.5 ohms between any 2 points (power supply to injectors, injectors to PCM).

Did you have the upper manifold off when checking resistance (or for further inspection)? If the upper manifold has been removed for previous repair, the harness could be in a pinch point that didn’t immediately affect operation, but over time has damaged the wiring. Keep in mind that all but 1 strand of a wire can be cut and you’ll still see 12 volts but it won’t allow adequate current flow to operate a load.

When you replaced the original PCM, were any of the terminals heat damaged (evidenced by the plastic being slightly melted or black soot in the connector)?

If the wiring and injectors are fine, the next step is to inspect all the power and ground feeds to the PCM. I can post that info later if you need it.

 

Injector resistance is 12 ohms for all , except one that is 11.8 ohms - according to the alldata.com site that's the exact value. +- 0.5 ohms.
wiring between injectors signal terminal and the ECM /PCM corresponding pins is 0.03 ohms, but basically if you just touch the terminals of the ohm meter to each other you get a resistance of 0.01 - 0.02 ohms so 0.03 to the injector i think is nothing . (only adds 0.01 )
I connected the terminals of the ASD relay to get 12 volts to the injectors without starting the engine. and they all get the same battery voltage. at that time it was 11.90 volt.
The intake manifold was off , because i can't access any cables otherwise. the injector harness is pretty much flat in its place , almost impossible to pinch a cable with the manifold ... :-(
i have taken in on and off 3 times already :-) to test the harness voltage when the car is running - will be almost impossible .......
ECM/PCM connectors seem fine - nice and clean like from the factory .

The thing that puzzled me is that when I put the 2nd "new" ECM/PCM it ran absolutely fine for a week,, maybe 10 days .
And I didn't touch any cables at that time . took off the old one from under the fender and plugged the new one in . and it was perfect .
after a week /10 days whatever i had to remove it because it stopped working - immobilizer light on - starter not working.
Driving one minute - fine . parked - tried to start again - immobilized !!!
had to plug in the old one again to get back home - naturally all 6 codes appeared instantly .

 

injector resistance is 12 ohms - should be good according to alldata.com specs. ...? one of them is 11,8ohm but close enough .
signal wire to PCM has 0.1 - 0.2 ohm resistance. basically nothing.
i did replace the starter before - that has a big grounding terminal on it - its in the same harness that goes to PCm - could that give "bad" ground to PCM ? ....hard to believe - its a big connector hooked to the top or the starter mounting bolt - like 13 or 15 mm . ....:-(
...hate computers .... :-(

 

Finally git the van fixed ( found a private repair shop with experience in this) ......turned out .....one of the pins was "pushed in " and the injector part of the ECM wasn't getting ground . Actually not the pin on the ECM - the "female" pin of the connecting cable .....one of those 4 big rectangular connectors with like 40 or 50 pins/connectors......Jeez drove me crazy . Don't really feel bad about buying new cables injectors spark plugs etc etc because its on 128 000 miles so it's like a "tune up" service . Shop charged me 500$ to find the bad connection ......but....i couldn't do it myself so i guess any price is worth it.

 

Try also checking the 2 large connectors near the throttle body for corrosion. These connectors are known to have problems with water intrusion and causing problems.
what r these 2 connectors connected to? one of mine right below the throttle body has corrosion on them

 

......Already got it fixed , thank god . That was the first thing I checked - most often advice you see online are those 2 big connectors because all the injector cables and sensors go trough there ....but everything was pristine - like from the factory ...... as you can see probably in the previous posts i did check the cables for short to ground and positive checked for continuity and resistance , from the injector plug to the ECU PCM coresponding pin .......checked the inectors resistance - it was whithn specs ..... even checked compression on all 6 cylinders .....it was all about the same....+/- 20 psi difference ......even with different ECM/PCM - what i call "car computers" - . i was getting misfire on cylinder 3 lots of times and then usualy misfire on all 6 cylinders ....i think the problem on cylinder 3 was causing the circuits in the computer to burn ....but thats ust my crazy theory - could be wrong...... eventually i started getting high pressure in the cooling system and the coolant turning orange instead of the regular light yellow green (Presotne) - i self diagnosed a blown head gasket .....oil mixing with coolant .....again - not an expert
.......got tired of going to repair shops and paying crazy money for no good results ....finally fixed it myself......unbelievable - what started in 2020 ....got fixed in 2023 ... -)

..........disassembled the top of the engine and the engine heads - bought a full gasket set on ebay for 60-70$ ......cleaned the old gaskets stuck to the aluminum .....sanded and polished the block and the heads myself ......bought a set of sandpapers from Amzon from 120 grit to 320 - 400 - 600- 800 - 1000 grit .....polished everthing like a mirror .....my intake valves looked clean but the exhaust valves were covered in carbon ....again ...got a full set of intake and exhaust valves - all 12 for like 80$ on ebay .....roto-polishing machine on amazon or 30$ and cleaned and polished all the ports on the heads - cleaned all the carbon build up - and it was a LOT ..... - got "lapping" compound from Autozone -8$? - seated all the new valves in the heads ......and assemled everyhing back .......since it was already open and accesible cheanged the crancshaft and camshat sensors - they are less than 20$ each .....pain in the *** to change with engine in regular operating condition - so why not do it when its easier and everything is open .....changed the inectors again - got a good set rom Amazon - chinese inectors or 60$ set o 6 ......checked again the cables running to the computer - for gazzzilionth time - all fine .....changed the water pump - because high pressure in the system damaged it .........and.....what do you know ......started and has benn working perfectly ever since for the last year ....spring 2023 ...till now ...writing in Feb 2024 ....
......i guess the moral of the story would be.....if you want it done done right - do it yourself ......
....I don't know if I ust had bad luck with repair shops that didnt have enough experience ....or is it ust how they operate - just trying to put a "band aid" on a problem - get the money - and send the customer away .....nut none of the 3 shops i went over time detected and ofered to fix the issue correctly ......None of them detected compression problem .....first one charged me even they said "We have no idea why it's misiring" ....but we charge for the time .......second one lied to me that they fixed a pin in the harness - which later i opened and it was factroy sealed - and it's clear nobody had opened it to do any work on it ......third shop even worse .....just changed the computer (that kept burning) from constant misifres,,,or just shops putting junk computers ....
......anyway .....Do it yourself guys ......works best.

 

......thats what blown head gasket does to yellow/green Prestone Coolant .....turns burned orange .....::-)