ECM not communicating with alternator's voltage regulator.


Asked by Dean Mar 14, 2016 at 01:54 PM about the 1998 Dodge Grand Caravan

Question type: Maintenance & Repair

Battery is not charging.  Was told regulater bad.  Replaced alternator have same
problem. Suspected bad wire to ECM or ECM.

12 Answers


The ECM in some manner controls the voltage regulator, which charges the battery.

11 people found this helpful.

The voltage regulator works all on its own. The computer does not control it in any way.

5 people found this helpful.

rowefast is a MORON the voltage regulator driver is a chip built into the dodge PCM and can only be fixed by 3 methods 1 replace pcm 2 bypass internal pcm voltage regulator with an external one however this will have a check engine light on and a code and the battery guage will read zero 3 remove PCM and take it apart and replace or re solder the voltage regulator driver chip if issue is intermittent then re solder

46 people found this helpful.

Yes the charging system goes through the pcm ,The Electronic Voltage Regulator (EVR) is not a separate component. It is actually a voltage regulating circuit located within the Powertrain Control Module (PCM) . The EVR is not serviced separately If replacement is necessary the PCM must be replaced.check the wiring fron the alternator for a bad fusible link ,also check the wire from the alt to the pcm(brown/grey wire) ,here are some diagram for that system . The pcm would have to be flashed if someone has the equiptment then it can be flashed at somewhere else than a dealer but if you dont know anyone that has the tools to do this (good scanner -snap-on etc)with the reflash capability then it has to be done at the dealer...

34 people found this helpful.

My 2013 grand caravan battery light came on and my transmission wouldnt go anywhere. Itbkept reving up while acelerating and slowing down tob18 mph max speed. I had no throttle. I had 8 dash lights on as well. When I had the battery checked, it said voltage regulator failed. So I bought a new pcm from the dealer and installed it. Then i had to tow it to the dealer to have it flashed and programmed so it would start. After they flashed the new pcm it starts and runs now but the battery light is still on. We had it check at oriellys auto parts store, it still says the voltage regulator failed. Question, is the pcm bad or alternator? Is there a battery shutdown fuse? All wiring is good

20 people found this helpful.

3 dead batteries in 4 months. Disconnect neg bat cable. Put circuit tester between bat and cable. Tested all fuses by removal. Light on circuit tester still on. Removed hot cable to alternator, tester light still on. Any help would be great. I will reserve my diagnosis until comments provide diag/options.

11 people found this helpful.

it would be better to use a meter with a amp and milli amp reading. the reading should be no more than 50 milli amps after the computer goes to sleep. You should wait at least three minutes for everything to shut down. if you still have a draw above that pull the big wire that feeds the fuse/relay center. If still a draw you will need to isolate main wiring branches. Pull wires from alternator etc..If drain goes away pull all the fuses including the maxi fuses. A wiring diagram would help.

3 people found this helpful.

Go to hardware/autoparts store, buy a plug like a trailer plug but with just two wires. It comes in a one piece you just cut in the middle, strip the wires, solder them to the alternator receptacle, take the other side of the plug and cut off the stock plug off the harness and solder on the other side of the new plug. Make sure you get the wires the right way around. Whether or not thats the problem right now can be in question but until you eliminate that shitty stock plug which can cause all sorts of weird problems, you wont know for sure and you could spend hundreds on all the wrong things.

3 people found this helpful.

Your Answer:

Grand Caravan

Looking for a Used Grand Caravan in your area?

CarGurus has 11,634 nationwide Grand Caravan listings starting at $2,495.


Own this car?

Share your experience with others.

1998 Dodge Grand Caravan

Review another car

CarGurus Experts

  • #1
    Whitney C
  • #2
  • #3
View All

Know more, shop wisely


Related Models For Sale

Used Chrysler Town & Country
214 Great Deals out of 4,141 listings starting at $1,777
Used Honda Odyssey
797 Great Deals out of 11,670 listings starting at $2,250
Used Toyota Sienna
601 Great Deals out of 10,746 listings starting at $2,400
Used Dodge Durango
909 Great Deals out of 14,753 listings starting at $1,700
Used Ford Explorer
2,324 Great Deals out of 39,525 listings starting at $1,800
Used Dodge Caravan
85 listings starting at $1,488
Used Ford F-150
6,025 Great Deals out of 108,768 listings starting at $1,200
Used Nissan Quest
33 Great Deals out of 582 listings starting at $3,250
Used Chevrolet Tahoe
1,546 Great Deals out of 20,793 listings starting at $1,900

Used Cars for Sale

2020 Dodge Grand Caravan For Sale
130 Great Deals out of 1,433 listings starting at $21,768
2019 Dodge Grand Caravan For Sale
68 Great Deals out of 3,461 listings starting at $14,499
2018 Dodge Grand Caravan For Sale
71 Great Deals out of 1,166 listings starting at $11,749
2017 Dodge Grand Caravan For Sale
53 Great Deals out of 1,130 listings starting at $6,795
2016 Dodge Grand Caravan For Sale
44 Great Deals out of 1,054 listings starting at $6,450

Content submitted by Users is not endorsed by CarGurus, does not express the opinions of CarGurus, and should not be considered reviewed, screened, or approved by CarGurus. Please refer to CarGurus Terms of Use. Content will be removed if CarGurus becomes aware that it violates our policies.