What's This Fault Code?

[Johndouglas]

A couple of weeks ago my neighbour lent me his Autel Maxiscan to play with.   My C5 seems to be running fine without any problems, but I connected the scanner to the car and detected a fault code P1597.   I erased it and when I ran the engine, it didn't return.   Yesterday I drove 90 miles down to the coast and back and the car performed well returning 54mpg on the display.   Today I connected the scanner and the same fault code is back again.   Any ideas what's causing it?  It isn't listed in my list of PSA codes.

[coastline taxis]

Youl never get citroen codes of anything other than a lexia or a top end scanner. So i wouldnt worry to much about it john as your mil isnt on so it could just be the scanner itself that is putting the code on

[Johndouglas]

Thanks Steve for chipping in.   I wouldn't have known about this 'fault' if I hadn't connected the scanner.   But I did wonder if it had anything to do with the rough running I wrote about last November when I was in Spain.   I only experience the fault about every 3 months, but it happened again last week as I left the ferry in Calais.   The dual carriageway ended in about 1/2 mile so I really booted the accelerator to overtake three HGVs.   As I pulled in, the car maintained it's speed, but it performed as though the fuel was being turned off and on again quickly.   I put up with it for another mile until I pulled into Pidou carpark where the tickover was a bit unsteady with some grey smoke.   I switched off and did the shopping, and as it normally does, when I started again, everything was back to normal.   A sweet tickover and no smoke.   Any ideas?

[qman3428]

Peugeot 407 p1597 cooling circuit bypass solenoid open circuit