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S300 "problems"
Posted: Sun Jan 31, 2010 6:02 pm
by blackek4
Hi too all!
I have a b16a2 which is very much stock apart from an itr tb (using itr map sensor), and exhaust (with stock headers). my s300 has a obd2a connector, and i use a plx sm-afr with gauge, having the NB connected to the stock o2 wire (D7) and the WB connected to D14.
Calibrated my sensors by the flowing parameters:
MAP - 0-1000 mbar
O2 - 0-1.5 and 0-5V (tested both settings)
A/F - 10-20 air/fuel ratio
ELD - 0-5V
My questions/problems:
1º - when i'm at WOT my s300 would read consistently AF 15.02 but my plx gauge show me values of 13.1-5 (which i assume is correct). is there something wrong with my sensor setup or plx installation?
2º - when i'm at part throttle, i get to the last columns of the table before i have my tps reads at 20%. and also when the car idles, my map reads values between 200 and 300 mbar. is this normal, or may i have a faulty map sensor?
3º - just as my vtec engages my mixture leans out (according to plx gauge) and then comes back to normal. is there a way to stop this from happening?
thanks for any help u guys can give me.
Posted: Sun Jan 31, 2010 6:12 pm
by fly_n
D14 is the narrowband input,
swap your wideband input to one of the other optional inputs & see how u go,things should get a little less weird.
Posted: Sun Jan 31, 2010 6:47 pm
by blackek4
here are the pinout diagrams i have from plx, as my ecu as an obd2 connection i think the d14 isn't the primary o2 input?
Posted: Sun Jan 31, 2010 7:13 pm
by fly_n
Ok,i missed that minor detail lol.
Im not sure exactly how hondata patch the obd2 connectors thru to the obd1 board & if indeed they do patch every pin thru,nor do i know what functionality the obd1 board u have has got,but,
I'll assume u are obd2A,since your talkin D connectors,
D14 is the second narrow O2 input.
what u will want to try if hondata doesnt generously chip in with exact advice in the meantime is,
try D16 for your wideband input,that should be your ELD input,then,
set your wideband input in sManager to D10 ELD.
it just depends if your ecu has ELD functionality,im not sure which do & which dont,or maybe all of them do & its just the vehicles that are not equipped with the ELD CT pickup.
if u have a multimeter handy ,u can confirm hondata have patched the D16 pin thru by just popping open the ECU & doing a quick continuity test thru to the D10 pin in the obd1 board.
Posted: Mon Feb 01, 2010 1:20 am
by blackek4
my doubt is very much the same, i don't know how hondata patch the ecu's with the obd2 connector, that is why i wired it to D14. i can only review my wiring next saturday, let's hope someone from hondata can clarify that before. if not i'll try it as you said.
thanks for your help.
Posted: Mon Feb 01, 2010 4:54 am
by blackek4
just to clarify my NB wire is connected to D7 pin.
Posted: Mon Feb 01, 2010 9:22 am
by fly_n
D7 - primary NB is correct.
U would fairly safely bet that all the non redundant pins are patched thru by hondata,i couldnt see why they wouldnt,its just that ive never seen an obd2 converter to be 100% sure.
Posted: Mon Feb 01, 2010 9:45 am
by blackek4
so if they are all patched trough the correct pin would be D16? that pin isn't refered in the pinout diagrams.
sorry for the persistence but i really want everything to go right this time.
Posted: Mon Feb 01, 2010 10:19 pm
by fly_n
those plx diagrams are vague as hell,no wonder i see so many questions on how to hook them up.
D16 is the pin,(obd2a side)
that is the ELD input,
set your input in sManager to D10 ELD,(obd1 side)
then its just up to whether the ECU has ELD circuitry or not.
If nothing seems to work then ,
obviously your primary nb input is reserved(D7/D14) i assume u want to keeep your nb working & run closed loop,
so only other 2 options are obd1 D12 & B6(whatever these translate to in obd2a).
it is very hit & miss whether an given ecu will have these last 2 options,its much more common to find an ELD input.
Thats why i send u there first.
Try it see what happens.
Posted: Tue Feb 02, 2010 4:44 pm
by blackek4
ok thanks for your help.
i guess i'll have to go trial and error this weakened then.
just a question to the hondata guys, is there any manual or some kind of document that explain where to connect the wires from plx (or any other wideband) for ecu's with obd2 connectors? if there isn't, would be nice to think of that to help people with that kind of ecu's. :)
Posted: Tue Feb 02, 2010 5:07 pm
by Spunkster
Posted: Tue Feb 02, 2010 5:31 pm
by blackek4
thanks for the help spunkster

Posted: Wed Feb 03, 2010 7:53 am
by fly_n
Again,i dont know what base your ECU is built on,i presume its just a P28 with no knock board,but,
If your motor starts getting all laggy,after u connect the wideband to obd2a 'D6' as hondata recommends in that diagram,its because your pulling timing all over the place from using your wb as a knock sensor.
Try the correct input 'D16' for obd2a ELD instead...
Posted: Wed Feb 03, 2010 10:58 am
by Spunkster
Sorry there was a typo and it has been fixed.
Posted: Wed Feb 03, 2010 2:40 pm
by blackek4
i'll try the D16 for wideband input on the weakened to see what happens.
something just got to me while reading the post's, i've been running my ecu in closed loop, the thing with the wideband wire, can cause what is happening to me? as i'm running in closed loop the signal that the ecu get isn't the NB signal instead of WB signal?
when i get my ECU in open loop my gauge shows a very lean AF ratio.