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Re: [ST] Check Engine Light on



Op donderdag 29 maart 2007 09:24, schreef Frederic NIZERY:

Fred,

Thank You for this information. Now I can start rewiring and testing the EFI. 
I will be ordering the device from scantool and with Your information and the 
Triumph service manual I hope I will bring this to a good end. 

Marc.

> Marc,
>
> Yes it is. ISO 9141.
> You can as part of the standard software OBDII port (PID).
> I think I noted at  home the bit map of the supported PID on
> my 02 ST.
>
> I use windows at home (linux at work) and I only tried windows
> software for that matter.
> http://scantool.net/?mode=displaySoftware&software_id=39&category=ScanTool.
>net I use also my PDA w/
> http://www.qcontinuum.org/obdgauge/
>
> Note that I don't have the bit map for the pre 02 engine. Probably the same
> except the O2 sensor which is not present on this model.
> I can read most of the sensor data and the fault codes. I can reset the
> MIL too.
>
> The problem that you could face is adjusting the CO rate as it's
> proprietary PID's.
> The throttle position sensor could also be a problem as the it's the
> absolute throttle pos
> that can be read and not the relative pos. The absolute pos is related
> to the potentiometer
> voltage reading, and the relative one is related to the corrected
> position as used by the ECU.
> To make it short, the relative position should be 0 or very close to
> when the throttle body
> butterflies are closed.
>
> But their is a trick to bypass that problem that works most of the case
> (worked for me).
> SOmething I learned reading carrefully the tuneboy online help. Fasten
> your seat belt:
> When starting, the ECU reads the relative throttle position RelPos.
> RelPos is calculated
> by:
> AbsPos - CorrectionFactor = RelPos
>
> If the reading is negative i.e. RelPos < 0, then the ECU recalculates
> the CorrectionFactor
> and keeps it in flash.
>
> The dealer procedure and the tuneboy procedure is to modify the
> CorrectionFactor (they can do it w/
> proprietary PID) turn on the key and then the ECU will compute a new
> CorrectionFactor to have RelPos = 0.
>
> TuneBoy event mention that they post-adjust the CorrectionFactor in a
> tiny extend. I think to avoid the
> stalling problem when the throttle close up rapidely w/o any charge (in
> neutral or clutched out).
>
> But you can reach the same point by setting AbsPos. Setting AbsPos means
> moving the throttle position sensor
> (it is on the left of the throttle body on the 02 engine) in such a way
> that AbsPos becomes lower than CorrectionFactor.
> But it's a blind manipulation as you can't read CorrectionFactor nor
> RelPos w/ the stadard PID's.
> Then the next time you switch the key on the ECU will adjust itself.
>
> Honestly I don't remind for sure if it's clockwise or counterclockwise.
> I could probably have a look at mine as I put
>  the sensor at the max possible position. But I have to remove the tank
> probably which is not so easy.
> Normally, giving the direction in which the butterflies rotate you can
> determine that yourself.
>
> Then how I know it worked? Because w/ an O2 sensor, when the ECU reads
> RelPos = 0, it will use the O2 sensor voltage
> to regulate the mixture. Then you can see it going up and down arround
> 0.5 volts (0.450V actually). And w/ scantool, the last
> indication of the first page (I don't know which PID it's related to)
> it's showing if it's driving, idling closed loop or idling
> open loop.
>
> The reason why I had to do that is because my dealer mechanic  wasn't
> able to fix a stalling problem properly and modified
> the pos sensor to enrich the mixture artificially (he didn't say it
> though). I just saw the scratches on the sensor screws.
> Result: no more O2 sensor regulation and a consumption going hight and
> higher when commuting.
>
> Hey, Hey. Are you asleep?
>
> Fred ST 02 BRG
>
>
>
>
>
>
>
>
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