Hondata

Hey folks,


K20Z1 05-06 RSX driveline w/Kpro ECU purchased new 05/10
Professionally tuned
Engine swap into a non-Honda/Acura race chassis, no factory wiring other than ECU harness. No check engine light.
Very small gel-cell Interstate battery
Marshall gauges and temp sending unit.

On cold start the car intermittently is on limp mode. Let run for a few seconds, turn the car off, turn it back on, and runs fine. No rhyme or reason. Can cold start 2-3 times with no issue, 4th time it kicks.

We have not looked for codes but suspect there will not be any. It's been hot since we built it, so ambient temp has been between 70-90 degrees for all starting situations.

Never happens when car is hot or after a long run.

We suspect it is battery or coolant temp related.

Is there a list or guide of what triggers can put Kpro into limp mode?

Are there tunable parameters that can affect entry into limp-mode (i.e. cooling temp low-limit, etc.?)

Thnx,

-Matt

You should use the 02-04 KPro with any engine swap vehicle - each 05-06 KPro is shipped out with a note attached to it to this effect.

Check your battery voltage while cranking the engine. When the ECU goes into limp mode, check if you can datalog from the ECU. If so, check what error code you get.

Yes, we did use the high $$ 02/04 Kpro (with new ECU) and adapter harness (the recommended Hondata -05/-06 RSX-S solution).

Aside from voltage, are there any other open sensor inputs (or a temp sensor, say, reading way low) that put it in limp mode?

There seems to be a common (mis)-perception stated on several forms that Hondata has some built-in protection device that disables VTEC a'la limp mode if temps are cold.

-M

No it does not put the ECU into limp mode.

For engine swaps you are supposed to use an 02-04 harness and transmission and a regualar K-Pro. The 05-06 conversion is not for use with engine swaps.

So, can you help the unwashed here understand the ramifications of using an 05/06 engine&trans, with Hondata-supplied 02/04 KPro ECU w 05/06 RSX-S harness outside of an RSX chassis?

This statement has been scattered around in various spots on Hondata tech info without any explain.

Your post above translates to: "05/06 drivetrains are useless outside of an RSX-S chassis if you have any expectation of tuning them with Kpro".

What is the hangup then, specifically in putting these outside of the RSX-S chassis?

The speedo output signal?

-M

You will have problems with vss, vtec, vtc, and the speedo. We do not support these swaps.

See http://www.hondata.com/techk20transmissions.html