I replaced my compessor due to code C2302. The Compressor was original on my 2004 VDP with 128,000 Km. All was well - for a bit, now I noticed the compressor is cycling too frequently (I think) at speeds over 40Km - drive cycle and a C2303 is set now.

If I let the car rest overnight - no settling on any corner, all measure 27 3/4in. So, is it in the realm of the possible that as my car gets up to speed a leak may develop in a strut that may normally be unnoticable when stationary?

Is it possible that a dump valve or other air system part is stuck or operating odd when I get to speed?

I have and ACI (AutoEnginuity) Scanner - no odd codes are raised other than C2303. I can do 2 way programing but I am not sure what to play with to diagnose.
So, next steps
Pull the battery cable and see what happens 24 - 48 hrs
Make up a set of "Brutal" style test gages and go around to find a leak
Give up and sell the car?

 

Not sure if you are aware but unless the car detects a too low condition, the compressor shouldn't run until you reach 40km/h so that would explain why it doesn't trigger until then.

Does the C2303 get set every trip or was it a one off?

I changed my compressor recently due to the C2303 error. There were no other signs of a problem but I got fed up with the light coming on each day.

 

I noticed the compresson cycling for long durations and often when speeds were over 40Km. I know that it is normal for the compressor to engage over 40Km, I was just not sure why the multiple / long run times? I can not detect an air leak. I have had the car parked with the battery disconnected and all 4 corner were measured before and after an overnight sit and show no sign of drop. I was able to hear the compressor cycle quite clearly over 40Km (I had a rubber bushing out of place).

Code C2303 did set 4 times now in the last month. Not every trip and I have not been able to corrilate to drive conditions (hot, cold, wet dry, long trip, short....).

I have soaped the valve block, fittings, air comp, etc. shock appear free of leaks. What I do not know is if a high pressure relief valve is leaking (or where same may be located) or what other location may be the souce of my air loss. Another thought may be that my compressor may not be making max pressure? It was just replaced but???