Adding WBO2 to 1227747

[EagleMark]

You can record data with TunerPro and Innovate LogWorks with LC1 Wide Band at same time, 2 USB cables.

[EagleMark]

You can also just watch O2 sensor voltage... during PE it will stay closed loop but O2 cross counts stop and does not change O2 sensor readings, O2 voltage is steady. .890 is about 13 to 1 AFR and .980 is closer to 12.5 to 1 AFR... I know everyone says not exact but that's what they keep coming out to when compared to WB...

If it's a built motor which I assume since it's been on DYNO just show him how knock counts go crazy when he hits PE, that's about the time the ESC test comes in and forces knock, 11 degrees first shot and 22 second shot, then run the ESC Done patch so this does not happen.


Here's my latest files for $42. HTH!

[dave w]

You can also just watch O2 sensor voltage... during PE it will stay closed loop but O2 cross counts stop and does not change O2 sensor readings, O2 voltage is steady. .890 is about 13 to 1 AFR and .980 is closer to 12.5 to 1 AFR... I know everyone says not exact but that's what they keep coming out to when compared to WB...

If it's a built motor which I assume since it's been on DYNO just show him how knock counts go crazy when he hits PE, that's about the time the ESC test comes in and forces knock, 11 degrees first shot and 22 second shot, then run the ESC Done patch so this does not happen.


Here's my latest files for $42. HTH!

Wow, You have been working Overtime!

Thank You!

dave w

[1project2many]

FWIW there is no IAT input to 7747 and code to support it would have to be changed in ROM. Data from external source is best answer. Portable scope with digital recording works well to show throttle and O2 voltages much faster than ALDL data.

[EagleMark]

Wow, You have been working Overtime!

Thank You!

dave w

Check out Paremeter Catagories in the XDF. Then change to Paremeter ordered List (which shows all) but then use Levels, 1,2,3, 4 and so on. As you need less to tune with choose lower number...

[mmigacz]

You can record data with TunerPro and Innovate LogWorks with LC1 Wide Band at same time, 2 USB cables.

Tunerpro gets the serial data from one wire off the 7747 ecm. If that wire is substituted with the serial data wire from the wideband, can you use tunerpro to only datalog wideband data? Would a special ADX be needed?

[EagleMark]

Maybe?

I've never tried because of two things.
One is I have a AutoProm so there are three available AD inputs to add to data stream with modifications to ADX.
http://www.gearhead-efi.com/Fuel-Inj...up-in-TunerPro!

Two is I have a LC-1 wideband which comes with it's own software to record data from it's USB cable.
http://www.innovatemotorsports.com/support.php

We looked at adding WB to a pin on 7747 pretty hard. Robert Saar went through the ECM and could not find a suitable circuit IIRC, not even the EGR could be used. One thing that cable makers have never tried is to add a AD inputs to their cables for external sources like the AutoProm has. Which would be a cool trick!

What kind of WB do you have and did it not come with software to see data?

[RobertISaar]

the only issue i remember off-hand with adding in wideband data to any C3 is that you have only very few routines that you can intercept to cause an A/D read on the PROM. though at 160 baud update rates, the data you'll get might not be very helpful. the EGR position inputs(for those that used them) will almost always work.

adding in A/D channels to an ALDL cable..... tricky, to say the least. if trying to do it without adding in a microcontroller, would have to find an A/D IC that would shift data out at 8192 baud..... if doing it with a MCU, then options open up quite a bit. there are some cheap MCUs out there that can communicate via UART and have a handful of A/D channels. IF one is found that can do UART at 8192 baud, then it could be connected directly to the same circuit. as soon as the checksum from the ECM's packet(if there is one) ends, then have the MCU start shifting out its data. it would act a lot like the autoprom without a lot of added complexity, would just have to develop code for a target MCU that allows it to keep track of when data is being transmitted and pretty slight mod to the ADX.

easier said than done though.

[EagleMark]

easier said than done though.

Would be a very cool addition to your cable!

EDIT: I just looked through the 7747 wiring diagrams and EGR is just 12 volt in. There does not seem to be anything that could be used... seems we have been here before?

Unless! The WB could take place of the NB O2 sensor? That's only 1 volt but some WB like the LC-1 can be programmed for one volt...

[RobertISaar]

that could certainly be done. if you didn't have one that supported the function, setting up a 1/5 voltage divider via two resistors would work as well.

[mmigacz]

that could certainly be done. if you didn't have one that supported the function, setting up a 1/5 voltage divider via two resistors would work as well.

I have a AEM uego wideband controller.

I am very interested what was being discussed by substituting the N.B. stream with the W.B. stream. However, you lost me when you said I would need to set up a 1/5 voltage divider via two resistors. Can you dumb that down so I can understand what to do or what to modify? This is great information!

If this is possible, it could only be useful in open loop for datalogging only, right? The ECM cannot use Wideband data to control the air fuel ratio, right?

[RobertISaar]

if you're familiar with how a potentiometer works, it is essentially that, just in a fixed position.

with a pot, you would have a maximum voltage on one terminal, ground on another and the 3rd terminal will have a voltage that is proportional to the rotation of the pot. all the way in one direction and you'll have ma voltage, all the way in the other and you'll have ground. move it to the center and it will be half of maximum. for example, if you had a 5V source and moved the pot to center, you would get ~2.5V on that circuit. much of the same would happen with a 0-5V signal, if you rotated it to the correct point, a 0-5V signal can become a 0-1V signal.

with using fixed resistors as voltage dividers, you have a single voltage division happening, instead of being variable like a pot.

going about it this way...... you could use it for closed loop control, but you'll be changing a LOT of values to get there.

[mmigacz]

if you're familiar with how a potentiometer works, it is essentially that, just in a fixed position.

with a pot, you would have a maximum voltage on one terminal, ground on another and the 3rd terminal will have a voltage that is proportional to the rotation of the pot. all the way in one direction and you'll have ma voltage, all the way in the other and you'll have ground. move it to the center and it will be half of maximum. for example, if you had a 5V source and moved the pot to center, you would get ~2.5V on that circuit. much of the same would happen with a 0-5V signal, if you rotated it to the correct point, a 0-5V signal can become a 0-1V signal.

with using fixed resistors as voltage dividers, you have a single voltage division happening, instead of being variable like a pot.

going about it this way...... you could use it for closed loop control, but you'll be changing a LOT of values to get there.

I attached a picture of how I would wire this option. Please confirm if I am doing this right. Also, is there anything else I would need to do? I just want to datalog the wideband output, so I would only be interested in doing this in open loop.

voltage divider2.jpg

[RobertISaar]

that looks exactly how i would do it for a 0-1 volt range. the O2 sensor amplifier will actually multiply the signal by a factor of 4.5, so you would end up with a 0-4.5 volt range. to make a 0-5V into 0-1.111V signal, using a 7.5K and 2.2K resistor will get you within 2%(1.134 volts), which is the same amount of error you could encounter from using a pair of 1% resistors.

i'm not sure how much impedance the O2 amp will allow up to, but IIRC, the 6811(and likely the 680x that the C3 uses) spec'd 10K. GM looks to have followed that pattern for most A/D channels.

[mmigacz]

that looks exactly how i would do it for a 0-1 volt range. the O2 sensor amplifier will actually multiply the signal by a factor of 4.5, so you would end up with a 0-4.5 volt range. to make a 0-5V into 0-1.111V signal, using a 7.5K and 2.2K resistor will get you within 2%(1.134 volts), which is the same amount of error you could encounter from using a pair of 1% resistors.

i'm not sure how much impedance the O2 amp will allow up to, but IIRC, the 6811(and likely the 680x that the C3 uses) spec'd 10K. GM looks to have followed that pattern for most A/D channels.

Whoa! Now Im confused again. Sorry, i'm not very savy when it comes to circuits.

Why do they (AEM) refer to the analog signal as 0-5V and not 0-4.5V?

I always thought the range volt range of the narrow band is 0-1V? Why should I be targeting 0-1.111V?

Vi = 4.5V
R1 = 7.5K
R2 = 2.2K

Vo = 1.0206V