Hey all first time posting here.

I've got a couple of problems with my 06 caravan 48000 miles. First is, something is draining my battery at night but not below about 11 volts, but enough to not allow enough cranking to start the engine. Went to auto store the did a test on it and said the batt was good but had a bad diode in the altenator, but its charging at 14.3v. Would the bad diode drain the batt????

About a week later engine light came on. The OBD gave me these codes

48 - don't know
100 - mass or volume air flow circut malfunction
400 - EGR flow malfunction
406 - EGR sensor A circut high
600 - Serial communication link malfunction

and one that looks like d4 on the reader that i couldn't find info on.

I read a thread on here i belive someone mentioned a 7/70 Federal emissions warranty. As my warranty is out any info would be appreciated.

Thanks for any help.

Matt

 

Check out this link to the EPA website regarding federal emissions warranties.
http://www.epa.gov/obd/warranties.htm

8 year 80,000 miles for EGR and Fuel/air metering systems.

Take it back to the dealer, print out that page if they give you a hard time.

 

Ok found a website that said to test for a bad diode set my DMM to A/C and check the charging voltage. It said if it reads anything its a bad diode. It read 30 just checking to see if this is an accurate test??

It also said that a bad diode would put a drain on the batt.

Also someone mentioned to me that my low batt situation my cause sensor malfunctions???

 

Yup, a bad diode or diodes will drain the battery. Think of them
as one-way check valves - electricity leaves the alt. but does not
go into it - until the doides have failed.

You can replace the diodes - if you are handy with a soldering iron.

 

ok had a mechanic do a drain test on the batt. Disconnected the starter,alternator and there was still a drain.So he pulled all the fuses one by one when he pulled the IOD fuse the draw stopped. After process of elimination when he disconected the BCM the draw stopped. When he reconnected the BCM The instrument cluster would not work. Does this have to be reprogrammed or ?????

 

think of a diode as a one way valve. it lets power go from alt to battery but is not supposed to let power go from battery to alt. I would replace the diode. it could let the power leak down over night if its not up to par.
the same applies to most diodes in most applications

 

ok "that" mechanic coulndt figure it out so....

Had the batt tested again ---bad batt but still a drain on the batt which is what caused the bad batt and also read a bad diode in the alt..

we took it to the stealership and wow what a day !!!

Explained bad batt and possible bad diode plus all codes which include EGR valve. Prior to signing for $108.00 diagnostic test for the drain.

1 1/2 hours later tech comes out and says " you have a bad battery and EGR valve the alt is good "
I say ok what about the drain he says we couldnt test for it because the batt was bad I said " NO SH%T I TOLD YOU IT WAS BAD "so the service lady says we owe 108.00 I said ok if I replace the battery and bring it back will you continue the test? She says sure for another $108.00 ....WTF .........I said why ? She replied because your not letting us replace the battery and the EGR valve ( by the way for $125.00 for the battery they said the wouldnt charge for install of the batt) .....$600.00 for the batt and EGR valve HUH

After 10 min of me and the wife freakin on her I paid asked for the managers # and left. Called the manager 20 min later he said no problem bring it back after the new batt and he redo the diag for free.

So got a new batt will check over the next couple of days for the drain ...

Sorry for the rant...........

Still dont know what the other codes are ??

Thanks for the help,

matt