On my ASA Camaro project test day, we were pretty excited to have the RacePak cl1 plugged into a legit obd2 port for full data mining ops.
When we fired it up, it blinked green, connected to my phone, then shut down. Many times.
Fresh batteries. Same.
Turns out the unit is compatible with ‘08 and later obd2 ports. Does anyone know a way to adapt these, or should I resign to picking up a signal from ignition? I was looking forward to having more info.
I took a quick look on Holley's site and couldn't see that limitation listed in the spec or manual, where are you seeing that is the case? I'd be reaching out to their support and seeing what they have to say. If it actually is limited to 08 up that's a huge limitation for a device like this with such a standard protocol and should be clearly stated everywhere.
It may be using CAN, which only became required for OBD-II in 2008. It was optional before that, manufacturers could have used a few other protocols.
If it is using CAN, you may be able to tap into the bus elsewhere, assuming a pre-08 Camero has one.
In reply to adam525i :
Ed Higginbotham called RacePak and they gave him the news. I found this to support it...
"This cable allows you connect your Vantage CL1 data box to the OBDII port on your 2008- or later model vehicle. One end features an M8 connector while the other end has a standard OBDII connector to allow easy connection for power and vital vehicle information."
In reply to Keith Tanner :
Thank you...the ECU on this car is an ASA race unit, so I don't know how that cross references to street units. There is way to tap the tach lead and at least get some data flowing, but I was dreaming for more. It could be the system for asa race cars was different than street cars...I would be surprised if C5 drivers had experienced a break down in data and not reported it.
A lot of race ECUs don't support any of the OBD protocol - not even allowed to by law in most cases because OBD output is very rigidly specified and spoofing it is a bad idea. They usually do offer a CAN stream. I don't know what ASA uses, if it's a cut down GM ECU you may still have options.
You need to talk to RacePak about connections to non-standard ECUs. The quote you gave sounds like a description of what a specific interface cable does, but that's not the same as identifying the correct way to talk to this ECU.
In reply to Keith Tanner :
Understood... I will call them back and dig deeper next week when the phones turn back on and report back ...this might be helpful to others in the future.
Thanks!
https://m.youtube.com/watch?v=Zr8zOwY1ai8
Here's how I take this. The cl2 is a simple post-2008 obd2 plugin. The cl1(what I have) is also post-2008 (regarding the use of the obd2) but because of separate data inputs, can be tapped, but one can still not simply plug in the obd2.
I will confirm this with Holley on Monday and update.
Check page 27, is your ECU one of these? Also, confirmation that it's using CAN. That's why it can't deal with OBD-II that's more than 12 years old.
https://documents.holley.com/track-day.pdf
Sounds like your datalink connector needs to have pins 6 and 14 populated.
Earlier GMs and some other cars used J1850.
Depending on the computer used, you MIGHT be able to extend wiring out to those terminals. I think. My head's been back into "convert Megasquirt data-out to high speed CAN" mode and trying to find an elusive supplier who made a conversion box six years ago but is nowhere to be found now.
I just spent some quality time exploring CAN/OBD2 for idiots. I think I need to rest my brain and try again.
There's definitely a lot of irrelevant information out there.
When you plug a scantool into the datalink connector, it becomes another device on the network, able to send and receive data. For your purposes, your device is not going to be sending any data, it is only going to be snooping stuff already being broadcast on the network. You don't need to know how to spoof this signal or that signal, you just need access to the broadcast.
All networks go (or are supposed to go) through the datalink connector. Which networks you are actually able to read will depend on what device you plug into it, but for your purposes all you need to access is the high speed CAN, which is what "critical" components communicate on (engine, trans, instrument cluster, ABS). That has the data you want to snoop, and I suspect is wht the device requires something '08-newer so that it can definitely get the data it needs off of that network.
It's more likely the dash is requesting info, not reading the broadcast. The latter is manufacturer-specific, so the RPM signal could vary widely from car to car. The responses to OBD queries are standardized - but also given a low priority. So "how fast is the engine spinning NOW?" is laggier than reading the native broadcast.
It looks like this thing can be set up to read the CAN broadcasts from some aftermarket ECUs, the list is given in that link I provided. If you use an OBD cable, it has to use the OBD protocol. And apparently it only speaks the CAN variant, thus the 2008 requirement. But that's only valid if you have a stock ECU that adheres to the emissions requirements.
CAN is the underlying protocol but does not define the format of the information.
OBD is a bunch of standardized responses to standardized queries used for diagnostics, and this information may (and after 2008, has to) use the CAN protocol for communication.
In reply to Keith Tanner :
Pete and Keith, thank you both. That's the most straightforward info I've read on CAN and OBD2.
I spent most of today on a ladder getting in some last minute house painting. Tomorrow night I will check the ecu. It is the original box run per ASA regs back in the day, so I'm not sure exactly how is configured. Obviously, there are no dash warnings, abs and such activated.
The ecu is GM #12480054 and was specific to the ASA series.
OK, so that's a standard GM PCM with a special reflash for the ASA series. Just like the one I have in my MG that started life in a 1998 Camaro.
Problem is, it's an old PCM. When talking to RacePak, see if/how they can interface with a 1998 Corvette or Camaro. Based on what I saw in the manual, it's with the tach signal wired into a coil and that's basically it for plug and play. You can add other sensors to three other channels if you want, but it's not going to be as easy as just plugging in to the OBD port. Since the thing has GPS and accelerometers on board, you'll get cornering and braking/accel info along with the tach and track positioning so you've got the basics of what you need for analysis.
And I just noticed the port you connect the OBD-II cable to is actually labelled CAN :)
And I just noticed the port you connect the OBD-II cable to is actually labelled CAN :)
Well, that's embarrassing.
I (obviously) have not messed with data ports before. I was just excited when the male and female fit..and assumed.
I used this cl1 in my 944 and simply ran it from the coil. It sounds like I will connect to a coil and use a multiplier...not as simple as plugging in, but it will get me where I need to go with fundamentals. I appreciate the support.
If it's a GM ECM that old, it should have a tach output at 4 pulses per crank revolution, just like a coil on a distributor. That'd be the one you probably want to tap off of as it should be fairly noise free, I'd think.
In reply to Pete. (l33t FS) :
Yea, it does and I have located that and tapped it for my shift light. That is the way to go.
If it's a pre 08 likely there is no CAN (some German cars did but less others) and you just have to do everything the old fashioned/hard way. I agree with Pete on the tach out config.
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