S300 "problems"

s300 and SManager software questions & answers
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Spunkster
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Joined: Fri Sep 20, 2002 5:06 pm
Location: Hondata

Post by Spunkster »

You cannot run closed loop from a wideband signal.
blackek4
Posts: 40
Joined: Sun Jan 17, 2010 12:06 pm

Post by blackek4 »

i know i can't, and that is exactly the doubt i have.

if when i run closed loop the signal that the ecu reads is the NB, how can that "bad connection" for the WB signal that i have affect the readings that the ecu does in closed loop?

sorry if i can't explain myself very well but i'm doing my best :)
travis1976
Posts: 26
Joined: Fri Jun 05, 2009 6:38 pm
Location: Biloxi, MS

Post by travis1976 »

wait...I have a question....I have a p28 and my white wire from my AEM wideband going into o2 sensor input d14 is this wrong? sorry for the threadjacking
1988 CRX B16A GT30R 450whp
fly_n
Posts: 258
Joined: Wed May 21, 2008 11:00 am
Location: Sydney Australia

Post by fly_n »

Sorry spunkster,any opportunity to have a dig at a bunch of bloody kiwis is a grand opportunity...u understand ;)

blackek4,u are a little difficult to understand,but,

Your WB signal at present is leading to a dead-end(obd2a D14),your obd1 ecu is not receiving the signal,obd1 does not have an input for secondary NB O2 sensor.

What u are datalogging & seeing on the graphs is the NB signal from obd2a D7 (which is obd1 D14).
u have your wideband input selection set to D14,so it is actually reading D7,understand?

If u want to see this,just bring up an 'O2' graph & an 'AF' graph on the same graph template. See how the signals look exactly the same?

Also bring up a 'L.TRIM' graph while your at it,
notice u have 19% long term trim happening right through that datalog u posted?

When u switch to open loop,that long term trim is disregarded & all of a sudden u have lost 19% fuel,hence the lean condition.

So in effect closed loop operation is just compensating for the current state of tune. Switch to open loop & see if u can find your way back to a decent AF & remember that your gauge is the only thing giving u AF readings at the moment until u find an alternative input to the ECU for your WB.
U can reset the L.TRim figure by just turning your ignition key off & pulling the ECU back-up power fuse in the engine bay fusebox( note "back-up" fuse not main ECU fuse)

Your MAP sensor seems to be ok, an idle reading(fully warmed up) of around 250mbar is normal.

U cant really know anything about the other problems until u get this WB input scenario figured out,until then,read your gauge.

travis- dont forget the issue of this thread is an obd2 to obd1 issue,do u have an obd2 loom in your car?
Also are u trying to run closed loop?
blackek4
Posts: 40
Joined: Sun Jan 17, 2010 12:06 pm

Post by blackek4 »

fly_n thanks for your pacience to explain it with such detail, it's all clear as water now. :)

i'll try to sort the WB input and let's see how it goes from there.

thanks again for your time :wink:
blackek4
Posts: 40
Joined: Sun Jan 17, 2010 12:06 pm

Post by blackek4 »

here it goes my test's during this weakend.

- changed wideband input wire to d16 pin
- changed wideband input in Smanager to D10
- placed ECU in open loop to test it and changed voltage offset to correct value.

and it works perfectly, finally i can get the same values in my gauge and in smanager. and the problem of not reading 15.02 AF at WOT despaired :D

i've been tuning my fuel tables for the weakened, so still in open loop for now, next weak i'll place it in closed loop and see how it goes.

thank you to everyone that helped :wink:
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