ECM not communicating with alternator's voltage regulator.


Asked by 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.

9 Answers


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

3 of 3 people found this helpful.

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


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

4 of 4 people found this helpful.

Excuse Me Ass-Hole? Everybody has a bad day.

1 of 1 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...

5 of 5 people found this helpful.

Charging Diagram...

7 of 7 people found this helpful.

Plugin and pin location...

3 of 3 people found this helpful.

And the Chart...

5 of 5 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

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