Daughter board communication error

K-Series Programmable ECU installation questions / support issues
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Daughter board communication error

Post by Hondata »

This is caused by low battery voltage. Generally the battery on its own should be able to crank the engine at 250 rpm with at least 10 volts while cranking. If not:

- Check the alternator is changing. A multimeter across the battery with the engine running should read 14 volts

- Relocated batteries often have an unacceptable voltage drop from the battery to the starter motor, even with car stereo type thick cabling.

- Consider using a higher capacity battery. The common Odyssey / Hawker Energy batteries do not crank very well, especially if they have been deeply discharged (even once). Consider using the stock battery. If you want to use lightweight battery, use the Braille battery, which has the same or bettery cranking than a stock battery.

- For engine swaps, check the alternator wiring.
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Post by Razathorn »

I have received this error multiple times when a bad battery or dead battery was in play. Here at a local honda-tech meet, I managed to forget my ignition and stereo was on while standing away from the car for about 45min or so and my car was dead when I got back. I got a push clutch start from some friends and instantly threw the daughter board communication error. The code would come back each time I cleared it with my odb2 box and kmanager -- during that time I couldn't rev past like 4k or so. The code stopped coming back after cleaning it on the next engine on/off cycle. It seems that regardless of if your battery is charged back up, you have to cycle the ecu and start the car again to get the code to stay off once cleared.

2003 black RSX type-s / jrsc @ 12psi / methanol injection / aftercooled