AEM wideband gauge reads 1.5 higher than readings displayed in HP Tuners software.

[jjs]

I just installed my wideband and it reads a bit higher on the guage than the reading that it sends to HP Tuners Scanner. I installed the gauge by selecting AEM from the list. The numbers on the back of the gauge are as follows-
4100-48901
35-8460

[Tre-Cool]

tried flipping your signal/earth wires around?

[mowton]

Analog wideband signals connected to the MPVI can exhibit excessive noise or offsets. These can be attributed to excessive wire lengths, too small a wire gauge, Bad power source, differences in ground references.

The first thing to do, and should be done initially is to make sure wire gauge is at least 14 gauge...and I always recommend that you twist this wire pair from the gauge to the MPVI. This will reduce picked up noise and essentially cancel them. The second thing in you initial setup is to make sure you have a good ground (chassis or battery itself) and a good, clean power source. Newer year cigarette lighter sockets may not be wire sufficinetly to supply the >2 amps needed to drive the gauge and the O2 heaters. Find a good source at a fuse block or even back to the battery. I have a cable (12 awg) that has two medium aligator clips to attach to the battery and a twisted cable (app 6 ft) back to a cigarette lighter socket where I can plug my WB power plug into for the best power source. Again, twist this cable run like the analog signal cable above. The last thing to do to make sure there are no ground reference differences causing the issue, run a separate ground wire from MPVI pin 5 back the the gauge power source ground. This will preclude ground differentials which can contribute to offset issues.

Now that you have a good, clean setup and still seeing differences in the gauge then user the User Defined option in the Transform window. Click once on the WB type and then click on the Fx which will illuminate at the top commnad line of the window. This will open a new area to allow you to cahnge the scale and offset values to tweak the readings. Only adjust the offset value up or down depending on the direction and amplitue of your error until the gauge and HP Tuners match.

Also remember that the gauge will only read 14.68 for AFR Stoich and 1.0 for Lambda stoich. If you have altered your commanded AFR to say 14.2 (which we do to meet the E10 fuel stoich) then there will be a difference between the gauge defining stoich as 14.68 and your HP Tuners commanding 14.2. In this case the gauge and HP Tuners will never match. That is why it is best to tune in Lambda as for any alcohol percentage, the Lambda value is always 1.0. E85 is worse as it has an AFR Stoich of 9.7.....

Hope this helps

Ed M

[jsllc]

There are two different AEM selections in the transforms section. I assume the gauge had 30-4100 and that is the model you selected. As mowton said make sure your ground is good.

[jjs]

Analog wideband signals connected to the MPVI can exhibit excessive noise or offsets. These can be attributed to excessive wire lengths, too small a wire gauge, Bad power source, differences in ground references.

The first thing to do, and should be done initially is to make sure wire gauge is at least 14 gauge...and I always recommend that you twist this wire pair from the gauge to the MPVI. This will reduce picked up noise and essentially cancel them. The second thing in you initial setup is to make sure you have a good ground (chassis or battery itself) and a good, clean power source. Newer year cigarette lighter sockets may not be wire sufficinetly to supply the >2 amps needed to drive the gauge and the O2 heaters. Find a good source at a fuse block or even back to the battery. I have a cable (12 awg) that has two medium aligator clips to attach to the battery and a twisted cable (app 6 ft) back to a cigarette lighter socket where I can plug my WB power plug into for the best power source. Again, twist this cable run like the analog signal cable above. The last thing to do to make sure there are no ground reference differences causing the issue, run a separate ground wire from MPVI pin 5 back the the gauge power source ground. This will preclude ground differentials which can contribute to offset issues.

Now that you have a good, clean setup and still seeing differences in the gauge then user the User Defined option in the Transform window. Click once on the WB type and then click on the Fx which will illuminate at the top commnad line of the window. This will open a new area to allow you to cahnge the scale and offset values to tweak the readings. Only adjust the offset value up or down depending on the direction and amplitue of your error until the gauge and HP Tuners match.

Also remember that the gauge will only read 14.68 for AFR Stoich and 1.0 for Lambda stoich. If you have altered your commanded AFR to say 14.2 (which we do to meet the E10 fuel stoich) then there will be a difference between the gauge defining stoich as 14.68 and your HP Tuners commanding 14.2. In this case the gauge and HP Tuners will never match. That is why it is best to tune in Lambda as for any alcohol percentage, the Lambda value is always 1.0. E85 is worse as it has an AFR Stoich of 9.7.....

Hope this helps

Ed M

Thanks Motown, I will look into making sure my grounds are adequate and go from there.

[jjs]

tried flipping your signal/earth wires around?

Which wires are you referring to? I don't want to flip a wire that will burn something up... I am still having the same issues I was having when I started this post. I can adjust the signal to be right on and it begins to slowly become off, I correct it and it gets off again.

[mowton]

I am not really sure I understand your problem. You seem to be saying you set the transform using the User Defined feature and after some time it drifts out and then you have to readjust the offset again...in the same direction, or back the other way? And you have to keep adjusting...again in the same direction or back and forth?

Can you post a log of the issue where you say the transform is drifting please ....

Ed M

[jjs]

I am not really sure I understand your problem. You seem to be saying you set the transform using the User Defined feature and after some time it drifts out and then you have to readjust the offset again...in the same direction, or back the other way? And you have to keep adjusting...again in the same direction or back and forth?

Can you post a log of the issue where you say the transform is drifting please ....

Ed M

Mowtown,
I kept experiencing this "drifting" issue until I went through with the calculator and set the AFR reading low and high slightly different then it had it in the default for an AEM gauge. I looked in the installation manual and it showed two different values for the readable range. One area states a range from 10-18.5 and another area says that it ranges on a table from 10-19.98 for AFR gasoline. I entered the 10-19.98 in the calculator and it gave me pretty close and stable results. I added another .4 to the 10 and it seems pretty close to being in sync with the HP Tuners software. Thanks for the help.
Jesse

[Trucker82]

Can you help me, I see you have posted a pretty good response here about proper setup of AFR Guage. I seriously have done EVERYTHING you mentioned yet cannot get my AEM 3310 to come close to reporting what the guage says compaired to what the scanner is reporting. SO! What other types of guages besides ANALOG are there that dont have high noise? What do you use for an AFR Guage? Thank you for the Help!

[Maxspeed96ct]

I just went through this on my aem x series gauge, you need to use the ground from the gauge not chassis ground to your hp tuners serial device.

So white from the gauge to the + inpout in hp tuners.
brown from the gauge to - input on hptuners serial