Wideband output to ECU?

FortLewisCobra

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Looking at adding a wideband to a 2003 Cobra and sending its signal to the ECU. Obviously this doesn't normally work but I would like a relatively easy way to datalog the wideband's output.

What I am considering is going with the Innovate LC-2 and sending use one of its analog outputs to send a wideband signal using a rear narrowband input on the ECU. Since this input was never meant to see 5 volts I would have to configure the analog output to use a .1-1.1v range but with a wider lambda range (.5-1.5?). The conversion formula for AFR would have to be adjusted then, as most of them are based on the 0-5v range.

It appears the LC-2 can do this.

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This would let me do things like data log using only the obdII port with my old diablo handheld and display AFR on my torque display with preset alarms. I've got a dual gauge pod that needs to go in but Id like to save it for some other analog gauges. I'm looking at doing e85 conversion and MS3pro pnp down the road so I need a wideband regardless.

I've done some googling and it looks like DSM and EVO owners use a similar work around to send wideband signals to the ECU but they have a 5V signal for emissions they typically use instead. Im comfortable setting up custom PID's in torque but I don't know if ours have the same option and my rear O2s are turned off so I know that signal is unused already.

Analog Inputs / EFIDynoTuning


TLDR: Use an otherwise unused rear O2 input to data log a wideband signal stepped down to .1-1.1v

-Is this possible with a LC-2?
-Has anyone used a narrowband input to monitor a wideband?
-Is there an otherwise unused 5v input on the ECU I can borrow?
 

Black02GT

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There is an output on the LC2 for a narrow band signal to the ECU it's 1.1=14AFR-.1v=15AFR This is where you problem is when trying to send an actual wideband signal to the ECU. If you change the voltages to be in the range on the wideband output it'll throw the ECU way off since that signal would be from 7.35-22.39AFR so the values would not correlate with the ECU's range of 14-15AFR.
 

FortLewisCobra

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There is an output on the LC2 for a narrow band signal to the ECU it's 1.1=14AFR-.1v=15AFR This is where you problem is when trying to send an actual wideband signal to the ECU. If you change the voltages to be in the range on the wideband output it'll throw the ECU way off since that signal would be from 7.35-22.39AFR so the values would not correlate with the ECU's range of 14-15AFR.

Yeah I'm worried the ECU would try to make sense of the signal when all I need is a way to track the voltage and I can set up a custom PID to do the rest. Will it do anything other than throw a CEL for an odd voltage from the rear O2?
 

01yellercobra

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How would using only part of the signal give you the full range though? Maybe that's the part I'm notunderstanding. If you're narrowing the wideband signal to narrowband limits are you still going to see the full range?
 

FortLewisCobra

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How would using only part of the signal give you the full range though? Maybe that's the part I'm notunderstanding. If you're narrowing the wideband signal to narrowband limits are you still going to see the full range?

I hope? According to the LC-2 user guide you can specify a specific voltage and lambda for the min and max of the range which implies it can be set to give 1.1 volts at 1.5 lambda (22.5 AFR) but I haven't found where anyone has actually done it.

DO not most people use EGR circuit for wideband 02 reading?

I looked for people doing it on here and corral but didn't find anything, it sounds simple and that might be the way I go.
 

bigja01cobra

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I know it is common on the HPtuners setups to just go through the EGR circuit you can try and search there. Believe they repin the ECM plug to get the data line in.
 

decipha

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yes you can setup the wideband to output .1 to 1 volt instead of 0 to 5v.

Yes its still a wideband.

The rear o2 obviously has to be disabled.

Most logging devices will not allow you to assign a transfer function to an inout so verify first.

yes the egr input works fine and is what most people use.

If using the egr input youd be significantly better off using an AEM digital wideband. Its far superior to anything AEM.

The link you posted has the details.
 

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