Autosport Labs

I've been experiencing a problem with OBD2 data as well and suspect I may have a bad cable.

When I first received my RC Pro2 last summer-ish, it did not receive power AT ALL through the OBD2 cable so I wired in a 12v source from the fuse box. After a couple of autocross events all the sudden power started back feeding from the OBD2 circuit through the RC Pro2 to the circuit I tapped for 12v. I know this because my radar detector which was on the same circuit and was now receiving power with the car off. At that time I realized the RC Pro2 was meant to receive power from the OBD2 cable so I removed the 12v power source. Since then I had problems with the car going into limp mode during autocross runs due to CAN bus faults - I am fairly certain this has been due to the RC Pro2 having connectivity issues through the OBD2 cable. At the last event I attended I could not get the RC Pro2 to stay powered up consistently so I disconnected it after the car once again went into limp mode from a CAN fault during a run. When the OBD2 cable was delivering power, I could not get any OBD2 data. This experience has been a bit frustrating to say the least and I would like to get it sorted out.

Any ideas on how to test the cable I currently have or other approaches to take?

Hi Brian, thanks for starting this new thread.

First question, did OBDII ever work, and what year/make/model is the car? I'm homing in on the ECUs CAN bus faults - trying to understand if this is an emerging issue, or was there all along.

It's true, RaceCapture/Pro MK2 has the 12v power connections joined internally between the terminal block and RJ45 port, which can cause backfeeding issues when both are connected. MK3 has internal isolating diodes; you can an isolating diode on the power connection to the terminal block to get the same effect.

Can you try plugging in RaceCapture using the same OBDII cable into a different 2008+ vehicle to see if it powers up and can read OBDII data?

Does RCP not power up at all when only plugged into OBDII?

Thanks, will watch for reply.

brentp wrote:Hi Brian, thanks for starting this new thread.

First question, did OBDII ever work, and what year/make/model is the car? I'm homing in on the ECUs CAN bus faults - trying to understand if this is an emerging issue, or was there all along.

It's true, RaceCapture/Pro MK2 has the 12v power connections joined internally between the terminal block and RJ45 port, which can cause backfeeding issues when both are connected. MK3 has internal isolating diodes; you can an isolating diode on the power connection to the terminal block to get the same effect.

Can you try plugging in RaceCapture using the same OBDII cable into a different 2008+ vehicle to see if it powers up and can read OBDII data?

Does RCP not power up at all when only plugged into OBDII?

Thanks, will watch for reply.

Hi Brent,

The OBDII data did work initially when the unit was purchased but the OBDII power did not. At some point the power started back feeding as stated previously. After maybe half a dozen events, the OBD started giving occasional can bus faults putting the car in limp mode. This degraded to the race capture unit turning on/off frequently and sometimes not powering up at all. That is where I left off attempting to use the OBD for power. I have since modified (carefully cut the single +12v wire in the bundle) the OBD cable to see if I could power the unit off the fuse box and use the OBD just for data. The result was the race capture unit maintaining power, delivering consistent GPS and accelerometer data but can bus faults still occurred and no OBD data was received. This past weekend I successfully used the race capture for GPS and accelerometer data without the obd cable connected.

The car is a 2013 Scion FR-S.

I will try to "borrow" a friends car this week to perform the test you requested. Please let me know if you have any other thoughts in the meantime.

Thanks

Hi Brian,

Ok - that helps quite a bit.

The Scion / FRS is one of the few cars out there that does not like seeing CAN bus termination at the far end of the CAN bus connection (on RCP's side).

RaceCapture/Pro MK2 has fixed CAN bus termination that can be disabled by removing the termination resistor on the circuit board, or on a later version of MK2, scratching out a thin copper junction next to the terminating resistor.

Once CAN termination has been disabled, then CAN / OBDII should work fine with your car.

It's a fairly straightforward process and we can provide instructions on how to do this. If you're not comfortable doing this, you can send it to us and we can make the changes for you.

Let us know and we can help you out; we'll watch for a reply here.

brentp wrote:Hi Brian,

Ok - that helps quite a bit.

The Scion / FRS is one of the few cars out there that does not like seeing CAN bus termination at the far end of the CAN bus connection (on RCP's side).

RaceCapture/Pro MK2 has fixed CAN bus termination that can be disabled by removing the termination resistor on the circuit board, or on a later version of MK2, scratching out a thin copper junction next to the terminating resistor.

Once CAN termination has been disabled, then CAN / OBDII should work fine with your car.

It's a fairly straightforward process and we can provide instructions on how to do this. If you're not comfortable doing this, you can send it to us and we can make the changes for you.

Let us know and we can help you out; we'll watch for a reply here.

Thanks for the quick response Brent. I am happy to perform the modification myself. A couple questions though:

1. Will this modification alter the ability to use the unit on other types of cars in the future?
2. Does your diagnosis of the issue completely explain the gradual appearance of the problems including not receiving power to the unit via OBD initially?

Thanks again!

1) It should still work with other vehicles.

2) Not at all.

The power issue is separate from issues around CAN communications. Without seeing what happened in action it's hard to diagnose retroactively, unfortunately. If you can power RCP only via the terminal block and have the OBDII connection not supply power, that would be the best option for you going forward.

I'll follow up with how to disable CAN termination; we'll get it posted in our wiki.

Instructions here:

https://wiki.autosportlabs.com/RaceCapt ... ermination

When disassembling your MK2, be sure to carefully unscrew the end plate screws, and when re-assembling, carefully hand-thread the screws to prevent cross-threading and stripping - recommend you use hand tools instead of a power driver.

Please keep us posted on your progress. Thanks!

The modification to the can bus termination seems to have fixed the issue. I am looking forward to trying the setup out this weekend to confirm the issue is completely resolved. I also set up the can bus mapping for brake pressure and steering angle and am super excited to see this data. Thanks for the assistance with my hardware issue and for putting all the time in for the the recent version updates!

One thing I want to mention since you gave a warning about potentially stripping the case screws: I was super careful removing the screws and only one of them came out easily. All the other screws had galled to the aluminum case and had aluminum cold welded in threads. I was able to use a die to clean up the screws and the fortunately case wasn't significantly damaged. If I had attempted to reuse the screws with out removing the galled aluminum first, I am sure the holes in the case would have become a mess. It might be worth looking at your assembly procedure to consider adding a lubricant/anti seize compound during assembly if people are frequently having issues stripping the case holes.

Thanks for the update. Glad to re-confirm the quirk with the FRS/BRZ platform and that disabling termination makes the difference.

With MK3 we've side-stepped the issue by going to coarser thread screws. But, we also have software-controlled CAN termination which prevents the need to open the enclosure!

Well, the saga continues...

In preparation for an event tomorrow I went to check the setup and once again no OBD/Can data is being registered in the RCP2 unit. GPS and accelerometer data still seem to be working. I tried power cycling the unit and vehicle multiple times with no success and checked the OBD cable connections.

Interestingly the car did not throw a can bus fault code as it has in the past so perhaps the modification to the can bus termination took care of that part of the issue. Any ideas on what to do from here?

Thanks

Hi Brian,

sorry to hear that. If you enable RCP logging and watch the output, do you see messages in there about OBDII channels being squelched? That would indicate RCP is not getting replies to it's OBDII PIDs.

Can you try in a different CAN OBDII vehicle as a comparison?

So I pulled the unit from my car and tried it on a neighbors car, also a 2013 FR-S (it was available on short notice). It worked as it should. I immediately tried it on my car and it also worked...oh the joys of troubleshooting an intermittent issues!

I guess I will have to try on a different make/model when the unit faults again. As far enabling the RCP logging and watching for that error message, just so I am clear, what menu is that under? Should I just press the logging button on the unit while in Dashboard? I don't recall seeing any error messages like you describe previously but would like to make sure I perform the test correctly.

Thanks

Glad you made progress. Here's the guide on various troubleshooting options. This will show you how to access the unit's log:

https://wiki.autosportlabs.com/RaceCapt ... leshooting

So I tried using the RCP2 today and the OBD data was not functioning as previously experienced so I looked at some logs as you suggested. What I saw was that it reported the CAN connection initializing successfully but then when I would select "debug" it displayed this message over and over: [CAN device] timeout RX CAN msg

While I didn't have another 2008 vehicle to attempt connecting to, I tried power cycling everything multiple times, I connected my cheap OBD2 scanner and made sure it could connect to the car without issue and clear codes though none existed. I also disconnected the car battery for a while but nothing I did resulted in any change.

Any ideas on what the issue might be?

Thanks

Hi Brian,

So reading back over the thread - it looks like it was working OK, and then with your most recent test, it stopped.

Did any settings get changed since then?

One thing we didn't check, are you on the latest firmware (2.11.0) and the latest app (1.9.0 / 1.9.1)?

If not, try updating to the latest app and firmware (http://podium.live/software).

After updating, remove all OBDII channels, write it to the unit, then add *just* RPM.

Ensure CAN is turned on and set to 500K, and ensure the OBDII is enabled as well. Write all final changes back to the unit.

Connect it again and watch for messages in the log file. Pay particular attention to any messages about "squelching OBDII channel".

Will watch here for updates!