Formula for AEM 30-0334

[mrGame]

I have an AEM 30-0334 gauge/controller and I just ran the wires to connect it to my MPVI Pro. It?s reading the voltage and I?m able to get AFR but it won?t match the gauge, it?s off by about 5 points. I called AEM and got their formula for it and it was closer but didn?t work. I tried both AEM folders in the channel and they didn?t work either. Has anyone else had that problem?

[dr.mike]

Are you using the analog output signal?

[1971StingRay]

Are you using the analog output signal?

Not to Hijack but,
I am using 30-0334 pinned for analog, reading AFR with a 98 Camaro and MPVI Pro. I have it populated as a channel on the left side list of Name/Values, but I am not sure how to pull/setup the scanner graph to log. When I add a new table should I select from MPVI Pro output 1 (how its pinned/wired), does it need user defined and if so what values? In AFR the gauge seems to be off and on the lean side a small amount vs what HPT reads.

The instructions have these values listed for 0-5V Output Scaling Formula:
AFR = (2.3750 * Volts) + 73215
LAMBDA = (0.1621 * Volts) + 0.4990

[anniversaryss]

Not to Hijack but,
I am using 30-0334 pinned for analog, reading Lambda with a 98 Camaro and MPVI Pro. I have it populated as a channel on the left side list of Name/Values, but I am not sure how to pull/setup the scanner graph to log. When I add a new table should I select from MPVI Pro output 1 (how its pinned/wired), does it need user defined and if so what values? In AFR the gauge seems to be off and on the lean side a small amount vs what HPT reads.

The instructions have these values listed for 0-5V Output Scaling Formula:
AFR = (2.3750 * Volts) + 73215
LAMBDA = (0.1621 * Volts) + 0.4990

The fornulas you have and the formula in HPT equal to the same value.
Your best bet is to try a better ground. Maybe even straight to battery or modify the paramter to match hpt

[1971StingRay]

The fornulas you have and the formula in HPT equal to the same value.
Your best bet is to try a better ground. Maybe even straight to battery or modify the paramter to match hpt

Sorry, I meant to say a few 10ths, IE 14.6/14.7 AFR on the gauge might display 14.9/15.0 in HPT. My concern is how to populate the graph with the WideBand table correctly with the gauge being its an analog reading. Do I take it from the MPVI Output 1? That doesnt seem to work. From the Serial as 30-4110? Then what parameters do I need to in the layout editor?

[2therock]

Go here guys, use the OBD port!

[anniversaryss]

1971Stingray no you use the other transform that says 30-***0 or somthing along those lines.
If your ground is good and you still have matching issues modify the offsets to make them match.

2therock not everyone has the luxary of using the obd2 port

[dr.mike]

It is important, when using any of the AEM 30-03xx widebands, to connect the Analog- wire directly to the ground pin of the MPVI. The analog- wire is not a ground wire on these widebands. It is an input line that the wideband uses to adjust its output to match the ground offset of whatever device is readind the analog+ signal. If the analog- wire is left unconnected, or connected to something else, the signal output will be wrong.


Also, note that the AEM 30-03xx gauges think that stoic ( lambda 1.000 ) is 14.65AFR. So, if you use 14.70AFR in your conversion formula, the scanner and the gauge will not match, when reading AFR. While 14.65 is technically more correct for most of today's fuel. It can be a bit confusion, if you are expecting the standard 14.7 value.

This is a good reason to use Lambda instead of AFR

[cobaltssoverbooster]

Go here guys, use the OBD port!

last i checked the obdII port does not work with gm computers prior to 2009. AEM used a 2010 camaro in the video so did things change?

[1971StingRay]

1971Stingray no you use the other transform that says 30-***0 or somthing along those lines.
If your ground is good and you still have matching issues modify the offsets to make them match.

2therock not everyone has the luxary of using the obd2 port

I didnt try this, my understanding was the gauge is set to be backwards compatible with the 4110, however now that I look at the directions it only says under the rs232 serial area not the analog... Maybe just for shyts and giggles I will switch it over.

[1971StingRay]

It is important, when using any of the AEM 30-03xx widebands, to connect the Analog- wire directly to the ground pin of the MPVI. The analog- wire is not a ground wire on these widebands. It is an input line that the wideband uses to adjust its output to match the ground offset of whatever device is readind the analog+ signal. If the analog- wire is left unconnected, or connected to something else, the signal output will be wrong.


Also, note that the AEM 30-03xx gauges think that stoic ( lambda 1.000 ) is 14.65AFR. So, if you use 14.70AFR in your conversion formula, the scanner and the gauge will not match, when reading AFR. While 14.65 is technically more correct for most of today's fuel. It can be a bit confusion, if you are expecting the standard 14.7 value.

This is a good reason to use Lambda instead of AFR

Thanks for the info, one problem I might have with mine is I grabbed the thinnest wire I had, only thing on hand small enough for the connector. Its probably 26 but might be 28 gauge wire. I do have some 20 gauge on the the way. I couldnt find any 20-22 at the Auto Zone, The Home Depot, Lowes or the dumpy little NAPA up the street...

I tried to do the LAMBDA but I left it all AFR as thats what I am familiar with but operating off of 1 as stoich does seem simple. I will post back if the wire issue or the default correction change doesnt get my HPT reawding closer to the gauge. I guess I should also ask how close should the gauge and HPT analog reading typically be? Are we talking .10 or .01 close? Side no I do trust the gauge for the most part, at high 15 AFR or so it begins to pop and breaks up a bit at idle. Couple part throttle areas that were mid-high 10 rich would stumble. Will def post a log after I get those pins rewired with a known heavier gauge.

[1971StingRay]

1971Stingray no you use the other transform that says 30-***0 or somthing along those lines.
If your ground is good and you still have matching issues modify the offsets to make them match.

2therock not everyone has the luxary of using the obd2 port

So I swapped out my wires to a 20 gauge and that tightened numbers up some but it was still off a decent amount. So I swapped over to the 030- 03xxx transform and now it?s right on. Not sure why this unit is supposed to be backwards compatible with the 4110 unit in serial but not analog...
Thanks for all the help, just got to get some time to drive it now.

[2therock]

last i checked the obdII port does not work with gm computers prior to 2009. AEM used a 2010 camaro in the video so did things change?

Thanks, I recently tried one of these on a 2005 Silverado and called AEM because it didn't log and was told its 2008 & Up. I checked the Vendor site and there was no model or year compatibility in the Add and they did an exchange crediting me the difference sending the 30-0300. I'm good now.

[cobaltssoverbooster]

Well that's a bummer. Good to hear they are helpful with the error.

[2therock]

Thanks, I wish someone would see my Boost 30-0306 thread and help me configure it. Its kicking my rear.