Guage and Flashpro readings are different. HELP!

FlashPro questions & answers specific to the 2006-2009 (US, UK, Asia) S2000
ek9max
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Guage and Flashpro readings are different. HELP!

Post by ek9max »

Wiring in a PLX wideband guage. The readings on the Gauge are different than what's being inputting to the flashpro.

I cut and soldiered the PLX 0-5v output to the ELD wire on the stock ECU.

I set the flashpro to disable the ELD, and set the wideband input to ELD.

At idle the gauge and wideband display on the flaspro are pretty close.

But during 3rd gear pulls the gauge is flat at 10.0 afr from 3500-8000rpm and the flashpro is seeing 11.7-11.8 all the way from 3500-8000.

What am I doing wrong???

P.S. I did not use a new pin for the wideband, I cut and spliced into the factory wire...... Does that make a difference?
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Spunkster
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Re: Guage and Flashpro readings are different. HELP!

Post by Spunkster »

Where are you getting the power and ground for the wideband controller?
ek9max
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Re: Guage and Flashpro readings are different. HELP!

Post by ek9max »

Power from fusebox, ground to factory ground.
ek9max
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Re: Guage and Flashpro readings are different. HELP!

Post by ek9max »

Where should I be drawing power and ground from?
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Re: Guage and Flashpro readings are different. HELP!

Post by Spunkster »

What factory ground are you referring to?
ek9max
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Re: Guage and Flashpro readings are different. HELP!

Post by ek9max »

Spunkster wrote:What factory ground are you referring to?

Factory harness ground.

Where should it be powered and grounded from? I can go check my installers work when I get home.
ek9max
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Re: Guage and Flashpro readings are different. HELP!

Post by ek9max »

And cutting into the factory wire 1" away from the harness is ok on the ELD wire?
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Spunkster
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Re: Guage and Flashpro readings are different. HELP!

Post by Spunkster »

The ELD wire should no longer be connected to the ELD itself, it should only be connected to the wideband signal wire.

What factory harness ground are you referring to? Where is this at?
ek9max
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Re: Guage and Flashpro readings are different. HELP!

Post by ek9max »

Spunkster wrote:The ELD wire should no longer be connected to the ELD itself, it should only be connected to the wideband signal wire.

What factory harness ground are you referring to? Where is this at?

Yes It's only connected to the wideband. but solidered in. Not repinned.

I'm not sure where the ground is. My installer just said "factory ground"

So if you could let me know where it's supposed to be grounded I can go home and confirm that it is grounded properly.
ek9max
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Re: Guage and Flashpro readings are different. HELP!

Post by ek9max »

Is there anybody I could call to get this resolved?

I would like to know where the ideal place to ground my wide band is.

Thank you!
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Hondata
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Re: Guage and Flashpro readings are different. HELP!

Post by Hondata »

http://www.hondata.com/help/flashpro/wi ... erface.htm

The wideband MUST be grounded at the same place as the ECU master ground. On the S2000 is the on the back of the cylinder head.
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ek9max
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Re: Guage and Flashpro readings are different. HELP!

Post by ek9max »

Hondata wrote:http://www.hondata.com/help/flashpro/wi ... erface.htm

The wideband MUST be grounded at the same place as the ECU master ground. On the S2000 is the on the back of the cylinder head.

Ok. So I can't splice it into the ground wire going into the ECU? Cant I just ground to the battery? Or do I actually have to run a wire all the way to the back of the cylinder head?

Also, Is it necessary to remove the ELD pin and replace it with a pin connected to my wideband? Or can I just cut the ELD wire and solider it to my wideband 0-5v output?

Also. I can't see this ground that you're talking about on the back of the cylinder head..... Do I have to get at it from the bottom of the engine?
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Re: Guage and Flashpro readings are different. HELP!

Post by Hondata »

You cannot splice into the ECU ground. If you do this the current drawn by the o2 sensor heater will offset the ground to the ECU so that all the ECU sensors will read incorrectly.
Grounding to the battery is not right either. The idea is to use the same ground potential as the ECU, and the right place to do this is at the ECU ground point.
The ELD pin can be cut or depinned; the only thing is to make sure the wideband and ELD are not both wired in.
The cylinder head ground is next to the firewall. It is hard to get to.

The problem is that the wideband analog output should have an isolated, floating ground, so that the wideband analog output does not share the same ground path as the sensor heater (which draws a lot of current). Most wideband controllers don't has a floating output, including the PLX. Because of this the heater current will alter the analog output voltage to some degree. The only thing you can do is to keep the wideband ground wire as short as possible.
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ek9max
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Re: Guage and Flashpro readings are different. HELP!

Post by ek9max »

My wideband ground is like 6". But it's grounded to a bolt right under the dash.....


So Now I gotta get it all the way into the engine by to the cylinder head. I can't even see this ground.....


You really think this ground issue is the reason I'm only seeing as low as 11.7 AFR? My gauge is seeing 10.0
ek9max
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Re: Guage and Flashpro readings are different. HELP!

Post by ek9max »

Grounded the wideband box to the cylinder head as instructed.

No difference. Gauge and factory wideband are maxing out rich. 0-5v input saying 11.7.

Please help.
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