AEM 30-0334-type direct OBDII wideband for older vehicles. Any takers ?

As some here know ( as they were involved :cool: ), the AEM 30-0334 OBDII enabled wideband was, originally, a project, developed here, on this forum. Basically, it was a partial re-programming of the AEM 30-0300 wideband?s CAN interface to conform to the OBDII standard communications. This allowed the modified 30-0300?s and, later, the proper 30-0334s, to interface, directly, with the HPTuners MPVI/MPVI2 scanners, via the OBDII pass-thru cable. And there was much rejoicing.
:yay:

But, there was one small(ish) issue. As the 30-0300 was, originally, designed to use its CAN interface for the AEMNet protocol, it did not include the hardware required to interface with vehicles that did not have CAN based ECUs. i.e. most vehicles, prior to 2007.

This left tuners of 1996-2007 OBDII vehicles, which used the J1850 ( VPW and PWM ) interfaces, to fend for themselves, in getting wideband data into the scanners. Either using the Pro version, with the ProLink CAN (which is ideal ), serial data, or, the old AC/EGR analog wiring tricks, each of which have their own issues; and, make dual-channel widebands very difficult to log.

So, having done most of the technical legwork, I am testing the waters here to see how many people would actually be interested in a 30-0334-like solution for the pre-CAN vehicles; specifically, earlier GM, Ford, and Chrysler products that use the J1850 variants, on the OBDII bus.



This would be an extra piece of hardware (as the 30-0300 does not have a J1850 interface) that would take the place of the pass-thru connector cable, used by the 30-0334. It would look like this ( as I already have the housings ) but, with terminals to connect the CAN wires from the wideband(s).

Attachment 112698

It would have the screw-terminals on one side, for the 30-0300 or 30-0310 CANH and CANL wires; and, would allow multiple widebands to be attached and logged, together. I will, probably add a cold-start safety function, as an option, to prevent thermal shock to the sensor?s ceramic elements. i.e. it would not start heating up the sensors until after the engine is stated.

That, pretty much, covers it; a J1850-enabled OBDII adapter for the AEM 30-0300 and 30-0310 widebands.

Looking at the current chip market, it looks like the pricing would be in the $70 to $80 range, depending on the demand volume. But, you do save the cost difference between the 30-0334 and the 30-0300/0310.

So, sharks? how many are up for a direct OBDII cable wideband adapter for the pre-CAN vehicles ( 1996-2007 ) ? This would, obviously, take a bit to get debugged and into production.

'cause I can never "just leave well enough alone." :banghead:

If I had a vehicle old enough I would be all over this.

I am very interested in this for a 30-0310 model. Could you possibly integrate a 12v power and ground supply to power the WB? I know if it was a permanent install, this would not be ideal due to battery draw, but for us guys constantly swapping our WB's into different vehicles, I think it would be great to just have to screw in the sensor, and plug this into the OBDII port, and bam.

I am fighting myself, over this. The problem is that if I provide a set of power terminals, I am SURE somebody will connect multiple widebands to it. And, that would draw too much power for the PCB. I might be able to stagger the harm-up cycles. If I did it, I would provide switched power. So, permanent installs would not be such an issue. The whole thing would need to sleep, with about a 20ma draw, when the engine is not running..

If it will work with older versions of the scanner, count me in, I?ll buy a few.
If I need to update to new version to be able to use it, I pass. I'm still using 2.24 and 3.6 for Pre-Can vehicles, I will never update my MPVI1 past 4.0 because older versions have features I'm not willing to lose.
For new vehicles I use a MPVI2, current version and a CAN wideband.

Well... my 1st test case is a SERIAL INTERFACE :eek:. That is pre- MPVI. So, I assume that it should work with the original MPVI ( Which I also have, for testing ). In theory, the device has no idea what interface is connected to it. I just acts like a J1850 node.

dr mike i would love to have one. i have two different widebands that that i have used both innovate motorsports. one being an lm-2 and the other is the mtx-l both work great but on the 01 trans am always seem to have ground offset that seems to change. that being said the serial to usb works great after you restart the laptop every time you plug it in.i drag race the trans am and being able to bring the wideband in under stand alone datalogging would be the most valuable thing i could do. hell i would pay extra if you needed few beta testers.on the power terminal part of it why not just warn that it will require relays for over so many amps.

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on the power terminal part of it why not just warn that it will require relays for over so many amps.

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Because. people don't read instructions :doh: Also, the OBD2 DLC connector can provider a maximum of 4A, which just covers the heat-up cycle of one wideband. Two, would, probably, blow the 5A fuse, pretty quickly.

I may, yet, add the power terminals. Because I have a problem, like that. :banghead: And, yes, , it would require a relay and direct battery connection for multiple WBs.

This device would only work with the AEM X-series widebands. i.e. it uses the same code that I used for the original 30-0334 project. So, it can't be used with the Innovate widebands ( even though they are among the worst offenders for ground offsets :( ) or, anything else that does not use the AEMNet CAN protocol.

If I tried adding a 0-5v analog input, I would end up with the same ground offset voltage issue as everyone else. Plus, I would need to deal with all of the scale/offset math, for every WB configuration :(

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Originally Posted by dr.mike

Well... my 1st test case is a SERIAL INTERFACE :eek:. That is pre- MPVI. So, I assume that it should work with the original MPVI ( Which I also have, for testing ). In theory, the device has no idea what interface is connected to it. I just acts like a J1850 node.

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That is cool, should work great then

I meant to say. I would be willing to go to aem if you could get this to work. I have thought about it before but with all of the vehicles that I tune on being p01 or p59 pcms I haven?t seen a real point.

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Originally Posted by whistler777

I meant to say. I would be willing to go to aem if you could get this to work. I have thought about it before but with all of the vehicles that I tune on being p01 or p59 pcms I haven?t seen a real point.

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Have fun with that. I contacted their customer service to get a couple of terminals JST SPUD terminals for the connector on the back so I could set up my analog outputs on my 0334 and they basically told me to pound sand. No one has them in stock. Not Mouser, Digi-key, Amazon, FindPigtails, not even the manufacturer. I would have to buy a min order of 8,000.
Finally had to go to Summit and pick up a new pigtail for an different AEM Wideband and will de Pin the connector. $30 shipped for two 5 cent terminals. Not cool AEM, not cool.

I'd be very interested. Some spare 0-5v inputs would be cool to inject something like fuel pressure into the datastream.

I probably have a couple hundred, around here, somewhere.

What are the differences we would notice on the scanner display/integration vs the Pro Link (if any)?

Currently, I am using
- Ballenger AFR500V2 (with a 2-pin connector on the power/ground and attachments to gain power from either interior charge port, or run straight to battery if needed)
- HPT MPVI2 with Pro Link

I was already thinking of ordering and using the 30-0310 to reduce the bulk of some wiring, and the control box/gauge display of the Ballenger (just use HPT for the gauge display)

If we can integrate the power/ground connections, that eliminates some more bulk of wiring, and another connection (I'm loving the sounds of this)

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What are the differences we would notice on the scanner display/integration vs the Pro Link (if any)?

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It would be the same as the difference between the 30-0334 and the 30-0300 ( via ProLink ). i.e. the widebands, connected by this method would show up, as if they were OEM sensors.

The range of the OEM sensors is 0-2.000 lambda. The range for the ProLink connected widebands is 0-6.553 lambda. This is, probably, only relevant to diesel engines.

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If we can integrate the power/ground connections, that eliminates some more bulk of wiring, and another connection (I'm loving the sounds of this)

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I think I will go ahead and add the power terminals and control switch. I hope people RTFM :cool:

But what if we can't read?

I'll only be using 1 wideband, and generally power it off of the charge port on the dash anyways (same fuse circuit as the OBDII port AFAIK) so I think I will be okay.

Absolutely count me on board now!! If you happen to need beta testers, count me in on that as well if you want?

I'll post here, when I have the 1st batch of beta units ready for testing.

The last issue I am working with is, when to wake the unit up. i.e. its default state has to be SLEEP, to prevent draining the battery, as OBD2 power is always-on. I know how to do that for CAN vehicles. But, I need to do some probing around, to figure out how to do it for J1850 vehicles. i.e. I need to see if there is any activity on the J1850 bus, when the IGN power is switched on.

The standard way, is to monitor the battery voltage. And, wake up, when it exceeds 13.0v ( engine running, with alternator charging ).

I have some spare time in the next few days in between moving if you want help testing this. My personal DD is an 04 Silverado Regular Cab. Would it help if I used a meter and tested the pins on the port (or a certain pin if you know which one) while in different modes?

Maybe?

Key off

Key on/engine off

Key on/engine running

Couldn't hurt :)

Sorry for the delay, moving is getting rougher in my older age! Lol

Using either ground yielded the same voltage reading in all 3 scenarios

Wires/locations used for testing (2004 Silverado OBDII port)
Pin 4 - Ground - Black
Pin 5 - ECM Ground - Black/White Stripe
Pin 16 - Fused Power Supply - Orange

Readings Found

Key Off - 12.61v

Key On/Engine Off - 12.26v (My blower fan, and radio was on)

Key On/Engine Running - 14.05v (Same accessories on as KOEO reading)