ODB replacement cable

[mtwlawson]

I recently bought a replacement cable for my race capture. The original had a broken catch on the RJ45 plug that was causing data loss.
When I installed the new cable the RC unit would not power up. I have discovered that ground the old cable was wired to pin 4 (chassis) on the ODB plug, but the new one is wired to pin 5 signal ground.

Is this a fault in the new cable or a design change? How should I proceed?

[brentp]

Hi,

Can you clarify if your old cable still powers the RaceCapture system?

Where did you purchase the new OBDII cable?

[mtwlawson]

Yes the old cable still works. I used a short RJ45 extension and taped it to the old cable to overcome to broken catch. I now have a working, if inelegant system.

The system and cable were both purchased from Petrel Solostorm.

[mtwlawson]

BUMP.

Is there anyone who does customer service?

[brentp]

It's great you found a workaround in the meantime.

We haven't yet seen an issue with these OBDII cables before not providing power to the device. So, it is a first for us seeing this.

Normally pin 4 and 5 are populated in vehicle OBDII ports and they both connect to ground - for low current applications they are typically considered interchangeable.

Can you peek into the port and let us know if there is a metal contact in both pins 4 and 5? What year/make/model is the vehicle?

We can check some of our existing cables to see if there are any variances.

[mtwlawson]

2014 Scion FRS

I will check the port tomorrow;

[mtwlawson]

Seems to have both connected

IMG_20220217_115804960.jpg (216.89 KiB) Viewed 11584 times

[mtwlawson]

I would have thought that for this application you would want to use signal ground. While they are at the same nominal potential signal ground should provide a less noisy signal for data. My car may be deficient in not providing a signal ground, but I don't understand why you would use chassis ground when I bought the unit and changed to signal ground without warning and perhaps even giving users the option of using pin 4 is pin 5 id not connected,

[brentp]

Hi, we'll check our existing stock to see how our current cables are wired.

Thanks!

[mtwlawson]

I need to know if ALL new cables are using Sig Gnd, if so are there is there a good reasons for the change from the original cable. If there was not an engineering reason for the change I will put a new RJ45 on the old cable and return the new cable. If there was a good reason for the change I will have to invest the time needed to find a Sig Gnd on the car and connect it to the ODB.

[brentp]

We checked our current cables and they do power up the unit on a standard OBDII port, tested on a Ford vehicle.

It's up to you if you want to return it, or put a pin in the OBDII connector of your car. Please work with your dealer on that.

Thanks for your patience with this unusual issue!