Never-Ending P0122

This code just won't go away on my 06 Jetta

Things we've done so far:

-Replaced the pedal switch
-Found and repaired damaged wiring harness between pedal switch and ECU
-Checked all 6 connections between pedal switch and ECU to be good

I'm really at a loss here. We replaced the entire cable run from the pedal to within 3 inches of the ECU, and all leads test perfect. Original pedal switch wasn't even bad. This can't possibly be so complicated...

Alldata does not show a P0122 for (what I am assuming) a BRM A5 Jetta sedan.

What component call out does VCDS show for this DTC? G79? G185?

Which pedal?

My Alldata show it as VAG 16506 "throttle/pedal position sensor/witch "A" circuit low.
TP sensor G7p / Accellerator pedal position sendor 2 G185, checking:
(then it tells you to check pins 1 and 5, 2 and 3 for at least 4.5v)
I did so, and that's when I discovered the wiring harness was damaged somewhere between the connector and the ECU. This was after I replaced the actual pedal sensor. I then created a new cable with a new connector and spliced it into the ECU harness.
I don't have VAG-COM, so the only thing I can tell you is that before replacing the harness, the throttle output reading on my regular OBD reader was always pegged at 94 percent, regardless of pedal position or the car running. Now it doesn't do that, but I still have the P0122 code.
I'm thinking there must be somewhere else that this is triggered, but I'm at a loss.

Yeah...you need a better scan tool.

Yep. Like the VAG I bought a few years back that worked great on my ALH cars, but not on this one Don't worry they say, we'll make you a special deal to "upgrade" to one that you can only use on 3 cars ever.

I just discovered this new thing they're doing. Is anyone happy about this?

I am using the exact same HEX+CAN USB cable now as I was 15 years ago. Not sure which version you have, but yes you may have to upgrade to a newer type.

The reason I say this (need a better scan tool) is that in some cases on some cars the generic OBD2 tool gets confused with the pedal position sensor(s) and the throttle position sensor(s) and lead you down the wrong path. Although I do not think that is necessarily what is happening here, but when you said the one value you are looking at doesn't change that makes me think you are looking at the intake flap position (which is like a throttle body, but not used on your car in the same manner it would be on a gasoline fueled car) and not the pedal position.

However you did say there was wiring damage, and that *could* lead to damage to the ECU although I highly doubt it.

What solution did you find with your engine code? I am suffering from the same code as well as turbo under boost.... trying to figure out what to change to get this car moving.

redbaron58p said:

Yep. Like the VAG I bought a few years back that worked great on my ALH cars, but not on this one Don't worry they say, we'll make you a special deal to "upgrade" to one that you can only use on 3 cars ever.

I just discovered this new thing they're doing. Is anyone happy about this?

Click to expand...

Let's see. They're offering a weekend warrior version of their Fully Functioning Diagnosis system at a substantially reduced price? In about 2008 I bought the USB+HEX+CAN for $349 and if they had offered the weekend warrior version back then I would have been all over that like a cheap suit.

If I had needed to add more cars, I would have bought more licenses. I'm pretty sure you can just purchase additional licenses if you need to.

The alternatives are the VW VAS tool for many thousands of dollars or something like the lame nose bleed expensive Snap-On diagnostic tool.