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factory limp mode?

Posted: Thu Sep 17, 2009 1:58 pm
by BlueRB240
Will it still be in place with the Nistune board? Trying to isolate some problems and would just like to leave the maf unpluged to eliminate it from suspicion.

Posted: Thu Sep 17, 2009 10:44 pm
by Matt
yes we leave that alone... so you can disconnect and it should still idle. if not disconnect temp sensor also

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Posted: Sat Sep 19, 2009 11:26 pm
by BlueRB240
Thanks it's helped me along my path :D

Posted: Fri Nov 20, 2009 8:30 am
by iceblade
is there any way to edit the limp mode... i.e. what is effected etc, say i wanted to make the car over fuel more or change the rev limit, is this possible??

Posted: Fri Nov 20, 2009 11:30 am
by Matt
not there isnt. those values are hard coded

Posted: Fri Nov 20, 2009 12:56 pm
by PL
I'm not sure about the older ECU's but the SR ECU's have a totally separate micro for limp home mode. So nothing we do on the NIStune board is going to affect it.

I'm not sure where the code is kept for the limp-home micro - I'm assuming it's all hard coded in the chip itself.

PL

Posted: Fri Nov 20, 2009 3:16 pm
by Matt
depends which limp mode you are talking about. the discussion in this thread was in regards to sensors

ie temp sensor, AFM sensor etc will result in the ECU picking a default value and using that to substitute for sensor value

what PL is talking about is processor limp mode (ie you didnt install or program the chip/board properly and now the processing logic on the ECU is dead). that is even lower level, where it just injects fuel for a fixed pulsewidth based on CAS pulses on later model ECUs (Type2+)