HowTo: Logging Wideband AFR via Rear O2 ECU ADC Input (Logging AFR without serial)
Aug 28, 2009, 07:09 AM
#17
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This way of logging Afr works really well.I found that you must run common ground point for the connected devices in order to have correct readings.This way the eval formula is acurate and doesn't need to be altered.
Tephra thanks for the eval&address for my romid
Does 53050009&53050006 use the same address like my romid?
Tephra thanks for the eval&address for my romid
Does 53050009&53050006 use the same address like my romid?
The offset works fine, it just took a second to match the Eval to the gauge output.
Aug 28, 2009, 02:43 PM
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What I do is to connect the orange wire from D35 plug with my W/B ground.The orange wire is the sensor gnd provided from the ecu to reference the input on the yellow wire.If there is any resistance between that pin and the W/B ground the readings are not accurate.If the resistance value is a lot you may see DTC 2252.
This works for me with almost 100% accuracy.
This works for me with almost 100% accuracy.
Aug 28, 2009, 04:03 PM
#24
What I do is to connect the orange wire from D35 plug with my W/B ground.The orange wire is the sensor gnd provided from the ecu to reference the input on the yellow wire.If there is any resistance between that pin and the W/B ground the readings are not accurate.If the resistance value is a lot you may see DTC 2252.
This works for me with almost 100% accuracy.
This works for me with almost 100% accuracy.
Ninja EDIT: might be worth including in the How-to.
Aug 29, 2009, 05:04 AM
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The orange wire has 0.5v reference voltage for the rear O2 sensor.My wideband has an analog output - that has to be connected for accuracy.With that connection i have accurate readings in Evoscan but ecu throws DTC 2252 because is checking that the reference gnd is below 0.5 v.This DTC is not causing any limp or backup and any malfunction to the ecu-DTC can be cleared.This works for me fine.If anyone feels uncomfortable on testing that please dont.I have done it without any problem so far.I also did offset the eval formula and seems to be working.
Aug 29, 2009, 05:37 AM
#28
you have to understand that widebands draw a lot of current, mainly for the heater, if you use the ref-ground as the wideband ground THEN you will overload the ECU.
IMHO its better to leave it disconnected and just ensure your REAL grounds are as good as they can be...
IMHO its better to leave it disconnected and just ensure your REAL grounds are as good as they can be...
Aug 29, 2009, 05:49 AM
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Pretty uderstood!My W/B has Aout+ and Aout-.I connected the Aout- to the orange wire.The heater gnd is on a different wire.Its confusing to think in greek and write in english!
Aug 29, 2009, 06:09 AM
#30
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If anybody wants a more "scientific" approach for the offset required for a specific ground, it would be very simple. Depending on your gauge/WB, you have different options. For my AEM, if the sensor is disconnected, the gauge is exactly 2.35V, which is equivalent to 14.7 AFR. Therefore, look at the value calculated for voltage in EvoScan when the gauge is not plugged into the sensor. LC-1's have programmable outputs, so you can set the output voltage to a constant known voltage to do the same. Then, just drive around a bit to confirm that your logged voltage is the same. If it isn't, offset it appropriately.