Power availability on OBDII connector ...

**EngineerSteve** · 03-12-2010, 06:16 PM

Hello all:

Is the 12VDC signal on the OBDII connector always on or is it switched with the ignition key?

If not always on, then is it determined by manufacturrer or make and model?

Thanks for your help...

**justchat_1** · 03-12-2010, 06:33 PM

always on

**Vitaliy** · 03-13-2010, 01:46 AM

Originally Posted by justchat_1

always on

Unfortunately, not true for all vehicles.

There seems to be no rhyme or reason to it. Very often the DLC shares the fuse with the cigarette lighter. So if your cigarette lighter has power when the ignition is off, most likely the DLC does, too.

Vitaliy

**jfitzpat** · 03-13-2010, 07:34 PM

Originally Posted by Vitaliy

Unfortunately, not true for all vehicles.

There seems to be no rhyme or reason to it. Very often the DLC shares the fuse with the cigarette lighter. So if your cigarette lighter has power when the ignition is off, most likely the DLC does, too.

Vitaliy

Can you point to some example vehicles? That sounds non compliant. The power is supposed to be unswitched (always on), and recommended best practice is for it not to be fused with accessory power.

-jjf

**Hebe** · 03-14-2010, 03:21 PM

Originally Posted by jfitzpat

Can you point to some example vehicles? That sounds non compliant. The power is supposed to be unswitched (always on), and recommended best practice is for it not to be fused with accessory power.

-jjf

OK, I'll chime in. My vehicle is a 2009 Chevy HHR and the FSM shows the power to the on at all times, but fused through the Front Power Outlet aka cigarette lighter socket.