The most frustrating error code ever( Daughter board communication error)

[hellfire]

So far error do not appear in normal conditions when engine starts normally.

But I would like to ask in advance how to deal with this error when would appear in future.

Let's say I have sudden troubles with starting engine, starter is draining buttery, anyway engine started but error appeared.
I have revlimit 4k, engine is working - what to do?


My first idea is to drive for a short while to let alternator charge battery a little, then (without stopping car and clutching) turn off ignition, and turn it on again.
So ECU will see that engine started without any voltage drop (because starter was not used), and should work normally?

Am I right? Would 4k revlimit disappear with such procedure?

It is quite critical in sport where it is impossible to go back to service area where I can reset errors using laptop - let say I am on rally stage, or racing stint and error appeared because battery low voltage during engine start.

[Hondata]

If I could remove this error I would. The cause is the ECU dropping communication with the KPro due to very low voltage. Almost always this occurs when cranking. The ECU can reset multiple times without you being aware of it.
A better approach would be to prevent the battery voltage from dropping when cranking. I've never had problems in my race cars with battery cutoff switches and 4.5 kg batteries. Pick a decent battery, keep the wiring short and thick, test the cutoff switch for any voltage drop, keep the battery on a trickle charger and replace the battery if it ever gets discharged. Unless there is a compelling reason I would never mount the battery away from the alternator and starter (ie engine bay).

[hellfire]

I fully understand that error is necessary, and not asking anymore to remove it from system.
First time I saw this error when my battery was partially discharged, so it had a reason and it is ok.

I am asking what should I do, when accidentally drain my battery to level where error occur.

Or in other words - in what conditions 4k revlimit would disappear?
In next ignition off-on cycle without voltage drop?

[Spunkster]

Try power cycling the ECU while the vehicle is stull running.

[hellfire]

Thank you. Good to know that :)

[hellfire]

Tested in racing conditions ;)
I left car with engine off, lights on and blower on for too long time when waiting in queue to start line, and catch "Daugter board..." and do not noticed MIL lamp.

After start I was surprised by 4000rpm redline, but on second gear turned off and on ignition (without pressing clutch pedal).
Check engine lamp was still on, but revlimit disappeared, so power was back :)

Fortunately that race was red-flagged and restarted, so I got another chance :)

https://www.youtube.com/watch?v=OVKpdBkPHzI