I’ve recently explored this topic and realized how little information there is regarding the importance of properly grounding your wideband controller and gauge can be to get the most accurate information. After all, this is the data you will be using to tune your vehicle with.
I am using an LC2 wideband in the o2 housing while simulating narrowband in DSMLINK. Gauge is an innovate DB gauge.
My problem:
My ECU was reading a certain air fuel ratio in DSMlink from my wideband controller while my wideband gauge was reading a different number in real time from the controller. These values were anywhere from 0.5-2.5 off from eachother often in the lean direction. This was observed by comparing the logged value LC1wideband in dsmlink and looking at my gauge.
Kevin Jewer of Six Sigma Tuning wrote up a tremendously helpful article regarding this issue. I HIGHLY encourage anyone with this particular issue to read this article.
Link: https://www.sixsigmatuning.com/wideband-o2-sensor-info
Essentially he states that 90% of the time, my issue can be resolved by using the same grounding point as your ECU for your wideband controller and gauge. Voltage is rarely an issue for this problem and most of the time it is ground related.
Galant VR-4:
Pins 101 and 106 on my ECU are ground. Verify your ground pins with a multimeter and back probe if necessary. You must follow these wires and ground your wideband to the same point(s). In my case, both ground wires went to different locations. This may not be your case, you need to trace your wiring, unplug the ECU harness and go hunt it down and hook to one of them. Soldering into this wire can work but I’ve been told it is more accurate to go to the exact grounding location.
I assumed that my ECU ground was on the corner bracket ground screw that holds the ECU in the galant so this is where I was hooked to originally. Pins 101 and 106 were the same black with red color adding to the confusion.
Please keep in mind every car may be different and I don’t know if all galants are the same as far as ECU grounding locations. At the end of the day, the ECU references a certain ground and your wideband references a certain ground. We need to make sure they are referencing the same ground so that the data is the same.
After following one of the ECU ground pins I saw it turn through my harness and head upwards into the dash to ground location #10 in the diagram below:
Ground location #10 is way up there above the metal crossmember tube. I had to remove my glovebox to get in there and use a short screwdriver. I could barely get the camera up to take this photo. Notice in the diagram it’s basically all the way up and behind the hvac vent on the passenger side:
I took a soldered ring terminal and put it on this screw, ran it down to my old wiring and soldered it all together connecting my wideband controller and gauge to this ground location. Don’t forget your shrink wrap.
My ECU and my gauge were now on the money with eachother giving me reliable readings to continue the tuning process with. I can now trust my gauge when I look at it which is a great feeling. It makes me wonder how many people might have very inaccurate readings and they don’t even know it. Check yours in dsmlink!!
At the end of the day every car, harness, ECU, etc are all different and can be setup any number of ways. This was just my experience in this galant which may or may not be like other galants. Trace your wires and follow the procedure either way. No matter what you have make sure your ground references for such an important device in the tuning process match your ECU’s reference. Just because your gauge turns on and says stuff doesn’t mean it’s correct stuff
I am using an LC2 wideband in the o2 housing while simulating narrowband in DSMLINK. Gauge is an innovate DB gauge.
My problem:
My ECU was reading a certain air fuel ratio in DSMlink from my wideband controller while my wideband gauge was reading a different number in real time from the controller. These values were anywhere from 0.5-2.5 off from eachother often in the lean direction. This was observed by comparing the logged value LC1wideband in dsmlink and looking at my gauge.
Kevin Jewer of Six Sigma Tuning wrote up a tremendously helpful article regarding this issue. I HIGHLY encourage anyone with this particular issue to read this article.
Link: https://www.sixsigmatuning.com/wideband-o2-sensor-info
Essentially he states that 90% of the time, my issue can be resolved by using the same grounding point as your ECU for your wideband controller and gauge. Voltage is rarely an issue for this problem and most of the time it is ground related.
Galant VR-4:
Pins 101 and 106 on my ECU are ground. Verify your ground pins with a multimeter and back probe if necessary. You must follow these wires and ground your wideband to the same point(s). In my case, both ground wires went to different locations. This may not be your case, you need to trace your wiring, unplug the ECU harness and go hunt it down and hook to one of them. Soldering into this wire can work but I’ve been told it is more accurate to go to the exact grounding location.
You must be logged in to view this image or video.
I assumed that my ECU ground was on the corner bracket ground screw that holds the ECU in the galant so this is where I was hooked to originally. Pins 101 and 106 were the same black with red color adding to the confusion.
You must be logged in to view this image or video.
You must be logged in to view this image or video.
You must be logged in to view this image or video.
Please keep in mind every car may be different and I don’t know if all galants are the same as far as ECU grounding locations. At the end of the day, the ECU references a certain ground and your wideband references a certain ground. We need to make sure they are referencing the same ground so that the data is the same.
After following one of the ECU ground pins I saw it turn through my harness and head upwards into the dash to ground location #10 in the diagram below:
You must be logged in to view this image or video.
Ground location #10 is way up there above the metal crossmember tube. I had to remove my glovebox to get in there and use a short screwdriver. I could barely get the camera up to take this photo. Notice in the diagram it’s basically all the way up and behind the hvac vent on the passenger side:
You must be logged in to view this image or video.
I took a soldered ring terminal and put it on this screw, ran it down to my old wiring and soldered it all together connecting my wideband controller and gauge to this ground location. Don’t forget your shrink wrap.
My ECU and my gauge were now on the money with eachother giving me reliable readings to continue the tuning process with. I can now trust my gauge when I look at it which is a great feeling. It makes me wonder how many people might have very inaccurate readings and they don’t even know it. Check yours in dsmlink!!
At the end of the day every car, harness, ECU, etc are all different and can be setup any number of ways. This was just my experience in this galant which may or may not be like other galants. Trace your wires and follow the procedure either way. No matter what you have make sure your ground references for such an important device in the tuning process match your ECU’s reference. Just because your gauge turns on and says stuff doesn’t mean it’s correct stuff
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