Hello,

I have tried three different scanners on my 2012 GL350 and none of them will connect unless the car is running. I turn key fob to the pre-start position, plug in scanner, it goes through all the protocols trying to connect and returns "communication failure". I have two Autel scanners newest is the MD808 Pro, and borrowed one at Autozone (think it was Innova) with same results.

Once I start the car it connects quickly. No issues with the car at all, I was checking for codes prior to state inspection to avoid any surprises.

I scanned it 2 years ago and it had no issues connecting in the pre-start condition. Is this something related to the keyless-go?

Any suggestions appreciated

 

If you're referring to the "pre-start" position as "two clicks" with your foot NOT on the brake pedal - yes, that is how I do it, as well. I'm not sure I can help with the actual problem... just wanted to confirm for you that you're doing it right. Try, just to eliminate variables, putting the key into the switch and turning two positions.

 

Correct - it is two clicks, then if I turn further it starts. I dont know if my foot was on the brake or not, does that make a difference? Instinctively I may have my foot on the brake.

 

In the first post, you mentioned Keyless Go... but now it sounds like you are NOT using that feature and physically have the key in the ignition? If so, you are doing it right and, no, your foot doesn't matter.