HELP PLZZZZZZ.. daughter board communication

[zilliboy]

Please some one help me, I have been getting this code for the past few months, since I got the car running...
Daughter board communication error ( low voltage at crank)

Does not happen all the times, but when it happens won't go away for about 20 times starting and turning off.
Brand new battery, cleaned all the grounds, don't know what else to do...
When it happen lap top won't connect either with ecu
Thank you....

[Spunkster]

What is the voltage at the ECU when cranking using a multi meter?

[zilliboy]

What wires would I check?
And what voltage

[Spunkster]

Pin A2 + and pin A4 -, you need to check the voltage when craning with a multi meter and see what it is when you are getting this error.

[zilliboy]

I tried today and it only happened once after that was fine and I could not get a reading, only when there was no light and it was 10, 11, and 12,
if It gets lower than 10, is it the alternator or starter?
Thanks for the help I'll try again tommorow...

[Spunkster]

If it is too low when cranking it will get that error. It can be caused by a weak battery, a battery that is not charging properly, or corrosion or resistance in the wiring.

[zilliboy]

Ok.... so the lowest number I saw was 9v, and the light only comes on after about 10 seconds, my question is, can the problem be at the edu/kpro or not it has to be on the charge system? Thank you, there is no corrosion battery is brand new , and it's charging good

[Spunkster]

Corrosion can be in the battery cables and you may not see anything as it can be inside the insulation. The voltage is dropping too low when cranking.

[zilliboy]

All 3 grounds are new wires, the ground from the battery is a new cable, terminals are new, battery is new, and just tried a new starter and nothing, same problem.

Does it have to be on the ground side? Or could be on the positive? And any chance it could be on the kpro?

Any ground inside the dash could afect?

[Spunkster]

It is not just the ground wires.

Has the battery been relocated?

[zilliboy]

Yes under passenger headlight

[zilliboy]

And also deleted air bag system ,and abs , inline fuel pump, and a lot of wires from inside, only tail light left


Could be inside the car the problem?

[Spunkster]

All of these could have something to do with this issue.

[zilliboy]

Ok .... you like to always say the problem is us, and grounds, ( I get that's the most common issue ) but in my case (after hours of work missed track times and calls to hondata, hondata forum and my seller tristate in NJ) I otnothing , finally talked to some one athondata( wish I knew his name so I could always deal with him....) he explains to me that there is a light that's supposed to come on when key is on and so and so, and he gives me a list of people and shops around me that install kpro and repair I'm in MA. So I go to my car and find out light is not coming on( nothing to do with ground, kpro is not connected at all) so I call people and find out things about it, so I take kpro all apart and re isnstall and it's working fine, one of the shops had a customer with same issue. And it was hondata with the install. Sorry for long post but wish you guys would consider other problems.

[zilliboy]

Now if problem persists what could be? Bad soldering? Because all I have to do is unscrew a lily bit and move it works. Thank you