I parked the car and heard the Air Compressor running after I had switched the ignition off. I thought I would leave it.... maybe 'settling' the suspension. After a few minutes I thought / realized: problem!
Switched on, started the car, switched off...all "fine" again!
Having read numerous posts about the 'O' (Air Suspension) relay failing AND a post about swapping it out with 'N' relay : that is exactly what I did!
Thought I'd 'save' the Air Compressor from possible over-running damage until I bought a new replacement relay. (I assumed the 'O' relay was 'sticking' on.....)
Yesterday the "Engine Warning Light' came on....
The error code read was : P0410 'Secondary Air Injection system Malfunction'
....which *DID* look familiar reading somewhere...........!
Yip : fuse chart 'N' relay : Secondary Air pump!
Seems as if I "transferred' the error by swapping out these two same relays!
Tonight I will replace BOTH 'O' & 'N' relays and hopefully;
1. Engine Light = OFF
2. Error P0410 = Cleared - without Agents clearing / resetting log!