Daughterboard communication Error-SOS

TODAPOWER · Post by **TODAPOWER** » Wed Jan 07, 2009 1:32 am

I have serious problem with my car,it is a k20a2 ep3 typer turbo 650+hp.
My battery relocated back,for 6 months the car work perfect,two months now i have problem with a hondata error code.

the error code:

Daugtherboard communication error(low battery voltage when cranking)
Vtc malfunction(the vtc malfunction does not find always)

So after that i have change:

two batteries
altenator
coils with stock again
ecu
vtc valve
vtc sensors
i made extra grounds from specific man to all the car.

the car work a little better..what i mean..?
When i used to accelarate always i saw the error code when i going to spool up good and suddently 4000rpm limited rev.
Now after 2-3 or 4 accelaration i have the same problem and i cannot make boost over 20psi because then ALWAYS safe mode frm hondata.

Please some help i need to change ecu or to find what happening.

Thanks!

Post by **Spunkster** » Wed Jan 07, 2009 10:27 am

The problem is caused by low battery voltage when cranking. Since your battery has been relocated, that is the most likely cause of the problem. Try putting the battery back in the original location and using the factory battery wiring.

cranny · Post by **cranny** » Wed Jan 07, 2009 11:11 am

run a stronger battery like 650 cca's. upgrade and run a 2 or 4 gauge at least power wire from it to the harness , and the same size ground in the trunk. make sure you battery is grounded properly in the trunk.

TODAPOWER · Post by **TODAPOWER** » Wed Jan 07, 2009 2:11 pm

Yes but for 6 months my car work perfect.
Suddently something happened.(i had my car for two months in my garage because i get off my engine to put sleeves.)

now

I test the best batteries and i make very good grounds,back where i put the battery.My volt is ok when i look out.BUT i noticed that when i read volt from k pro i read 13 13.2 13.8 13.5 14 13.8 13.5 is that normal?

TODAPOWER · Post by **TODAPOWER** » Wed Jan 07, 2009 2:19 pm

Spunkster wrote:The problem is caused by low battery voltage when cranking. Since your battery has been relocated, that is the most likely cause of the problem. Try putting the battery back in the original location and using the factory battery wiring.

It is unpossible.I have no room. :(

Post by **Spunkster** » Wed Jan 07, 2009 2:47 pm

http://www.hondata.com/forum/viewtopic.php?t=4877

TODAPOWER · Post by **TODAPOWER** » Thu Jan 08, 2009 2:40 pm

Spunkster wrote:http://www.hondata.com/forum/viewtopic.php?t=4877

Yes i have already read this but waht am i going to do.I cannot put the battery again front.And why this happened suddently,is anything else i can do?Maybe a crankshaft sensor?
:?