Throttle position sensor fault maybe?

[Trubshoe]

VW Golf Cabriolet ADY 2.0 8V auto

The car won't start unless you pump the accelerator then I can drive it, if I "left foot brake".

If I take my foot off the accelerator the engine dies. I ran diagnostics on it and got a throttle position out of range, 0530. Then I clicked clear fault in the diagnostics and the engine started normally and idled ok. I took the car for a drive and the same thing happened, the engine cut out while running down hill. I returned home using the left foot braking, keeping the reeves up with the right foot. I did another diagnostics and got something about "idle speed regulation 19-00 lower limit 0533"

Then I cleared the fault. The car started normally, and I went for another drive and this time the car did not stall. This is really doing my head in.

Could it be the throttle position sensor, I assume this controls the idle as well?

Why does clearing the fault code, temporarily fix the fault?

I would take it to a mechanic, however because the fault is intermittant, no doubt it will not play up!

Any ideas appreciated!