I have my Innovate LC-1 analog out 2 wired into the ELD pin E15 on my PRA ECU and am getting a voltage offset of around -0.6V. When I disconnected the analog out from the LC-1 and popped my voltage meter on the ELD pin when it was connected to nothing I read around 4.35V! When I did the same later I read a voltage of almost 0V.
Is there something else I need to do before connecting the analog output of the LC-1 to this pin on the ECU? The LC-1 is reading the correct AF but the ECU is displaying a leaner AFR. For example, when the LC-1 serial output is reading 14.7 AFR my ECU thinks it is around 15.6 AFR. I have checked all the grounding etc for the LC-1 and am thinking it may be an issue with the ECU connection as the voltage offset is much worse once connected to the ECU.
PRA ECU ELD PIN E15 VOLTAGE OFFSET
done some playing with this....
got a new LC-1 out of the box and a new PRA ECU
when you connect the LC-1 to the ELD pin, the line voltage is raised, how much depends on where in the 0-5V range you are, but in free air it's over 5V (seems to settle on 5.09V)
now cleary this makes the calibration of the screen AF different from the LC-1's intended, and at 12/1 AF it's about 0.6 different (this is from what the LC-1 is saying over it's serial link)
My guess is that the ELD input has some kind of pull-up resistor on it and the LC-1 has no closed-loop feedback on the output?
the Narrow band output appreas to have another issue, when used into the primary Lambda input, it looks like it never exceeds ~0.25V according to the ECU...
that said, this is less of an issue as all you want to see is the transition from <0.1V to >0.2V around Lambda 1, and this seems to work just fine (I did have to slow the LC-1 down to 1/12 of a sec output as it was going a bit nutts)
5V output wise , should have some time tommorow to go thought he whole range (on the dyno) and come up with a new Voltage/AF table...
got a new LC-1 out of the box and a new PRA ECU
when you connect the LC-1 to the ELD pin, the line voltage is raised, how much depends on where in the 0-5V range you are, but in free air it's over 5V (seems to settle on 5.09V)
now cleary this makes the calibration of the screen AF different from the LC-1's intended, and at 12/1 AF it's about 0.6 different (this is from what the LC-1 is saying over it's serial link)
My guess is that the ELD input has some kind of pull-up resistor on it and the LC-1 has no closed-loop feedback on the output?
the Narrow band output appreas to have another issue, when used into the primary Lambda input, it looks like it never exceeds ~0.25V according to the ECU...
that said, this is less of an issue as all you want to see is the transition from <0.1V to >0.2V around Lambda 1, and this seems to work just fine (I did have to slow the LC-1 down to 1/12 of a sec output as it was going a bit nutts)
5V output wise , should have some time tommorow to go thought he whole range (on the dyno) and come up with a new Voltage/AF table...
I have moved the LC-1 to the secondary location and reinstalled the primary sensor. I'm just going to use the LC-1 for post-cat AFR readings using Logworks just now. If I can get the correct voltage reading through the ELD pin in the future I will use it for datalogging. I think you are right about the pull-up resistor on the ELD input, but I can't cut it until someone can tell exactly which one it is!Stuart wrote:done some playing with this....
got a new LC-1 out of the box and a new PRA ECU
when you connect the LC-1 to the ELD pin, the line voltage is raised, how much depends on where in the 0-5V range you are, but in free air it's over 5V (seems to settle on 5.09V)
now cleary this makes the calibration of the screen AF different from the LC-1's intended, and at 12/1 AF it's about 0.6 different (this is from what the LC-1 is saying over it's serial link)
My guess is that the ELD input has some kind of pull-up resistor on it and the LC-1 has no closed-loop feedback on the output?
the Narrow band output appreas to have another issue, when used into the primary Lambda input, it looks like it never exceeds ~0.25V according to the ECU...
that said, this is less of an issue as all you want to see is the transition from <0.1V to >0.2V around Lambda 1, and this seems to work just fine (I did have to slow the LC-1 down to 1/12 of a sec output as it was going a bit nutts)
5V output wise , should have some time tommorow to go thought he whole range (on the dyno) and come up with a new Voltage/AF table...
Let me know how you get on with the dyno experiment....
Does LC-1 have differential outputs?
I'm using a Tech Edge 3B1 wideband module with differential outputs and I'm not experiencing voltage offset problems.
May be this link can help: http://wbo2.com/sw/wblinout.htm
If there are no ground issues, another test you could do in order to check the accuracy of the ECU datalogger is to connect a voltage calibrator between ground and ELD pin, so you can input some reference voltages with the calibrator (eg. 1, 2, 3, 4 and 5V) and see if there is a difference respect what the ECU is reading. If there is a voltage difference, that can be corrected with a resistor.
I'm using a Tech Edge 3B1 wideband module with differential outputs and I'm not experiencing voltage offset problems.
May be this link can help: http://wbo2.com/sw/wblinout.htm
If there are no ground issues, another test you could do in order to check the accuracy of the ECU datalogger is to connect a voltage calibrator between ground and ELD pin, so you can input some reference voltages with the calibrator (eg. 1, 2, 3, 4 and 5V) and see if there is a difference respect what the ECU is reading. If there is a voltage difference, that can be corrected with a resistor.
I will set the LC-1 to flatline at 0,1,2,3,4 & 5 volts and see what voltage the ECU reads. I'll try and work out a way to get it reading correct AFR's. Hopefully the offset is linear so I get away with a set offset. I don't think it is though as previously after switching off the engine with the AFR at around 18 the offset was around 0.3V as opposed to 0.6V at 14.7AFR.Maverik wrote:Does LC-1 have differential outputs?
I'm using a Tech Edge 3B1 wideband module with differential outputs and I'm not experiencing voltage offset problems.
May be this link can help: http://wbo2.com/sw/wblinout.htm
If there are no ground issues, another test you could do in order to check the accuracy of the ECU datalogger is to connect a voltage calibrator between ground and ELD pin, so you can input some reference voltages with the calibrator (eg. 1, 2, 3, 4 and 5V) and see if there is a difference respect what the ECU is reading. If there is a voltage difference, that can be corrected with a resistor.
Wish me luck tonight....
Car back to normal, running okay. Stock primary back in and LC-1 in secondary location. I calibrated it last night and surprise surprise it has lost the calibration again.
IMO AVOID THE INNOVATE LC-1. It is too temperamental and unreliable. I will probably uninstall mine altogether when I can be bothered. At least it is not effecting the running of my car now!
IMO AVOID THE INNOVATE LC-1. It is too temperamental and unreliable. I will probably uninstall mine altogether when I can be bothered. At least it is not effecting the running of my car now!
Calibrated the LC-1 again...seems to be working for now. Programmed analog output to default. I set the output to flatline set voltages and read the ELD pin voltage to work out a conversion table. Here's the results:
LC-1 V---ELD V------AFR
0---------1.333-------7.350
1---------1.958-------10.358
2---------2.681-------13.366
3---------3.413-------16.374
4---------4.145-------19.382
5---------4.853-------22.390
Looks to be giving reasonably accurate AFR's in KManager now :-)
Fingers crossed that it remains so. I'm not going to touch it now!
LC-1 V---ELD V------AFR
0---------1.333-------7.350
1---------1.958-------10.358
2---------2.681-------13.366
3---------3.413-------16.374
4---------4.145-------19.382
5---------4.853-------22.390
Looks to be giving reasonably accurate AFR's in KManager now :-)
Fingers crossed that it remains so. I'm not going to touch it now!