Does error code C2303 refer to bad earth point or a need for replacing the air compressor.

 

Refers to weak compressor-try replacing the piston seal.

 

Is it the original compressor ? What year and miles ? Early compressors started to fail quite early on and some didn't even make it within the warranty period. On my own 2003 X350 the compressor was on the way out at 35k miles. The replacement was still on the car at 115k, when I part-exed it. Seal kit is cheapest if you are OK with DIY, otherwise they are available on the internet.

 

For the record, noting this is a 2 year old posting, but others will find it when they get the code, for me in a 2004 XJ6, the fault code turned out to be a bad right rear air strut. I replaced it, reset fault codes, the strut pumped up to correct height and the ride stiffness went away. This is not to say it always is a bad strut, but C2303 can be. Using my Autel MP808 MaxiPro, the error said "levelling implausible" and the description said compressed air was leaking... and indeed it was, in the strut (air suspension).

 

hi DonA
where was your leak on the strut as ime getting this code 2303 (i have a full kit to rebuild compressor) is the leak on the rubber at top of strut ?
the code comes up when driving on my car but not every time i use the car
i use the thinkcar 2 diagnostic on my iphone unit plugs to port on car, works well checks all modules i need for codes
plus u can choose extras with paypal payment, suspension was £3 so u dont have to buy every maintenance module at once.
obd free onward