Picasso Overheating warning - P023B, P0598, P0947

Writing this up in case it is useful to other people.

C3 Picasso 1.4 VTR+ 2011 (petrol)
67,700 miles

Engine warning lights appeared on dash - overheating, stop engine immediately
Stopped engine. Noticed top radiator hose warm, bottom one cold. Recovered to home then driven short drive to local garage.

Replaced thermostat and radiator (because it had a leak at the bottom) - £470. Garage unable to sort electrical problem.

Engine lights still on.
OBD scan showedP023B - water pump control - short circuit to ground
P0598 - Adjustable thermostat control - short circuit to ground
P0947 - Oil pressure adjustment valve control - short circuit to ground

Harness checked - no fault found.
No power feed to ecu circuit
Traced back to fuse, found blown. Replacement fuses also blow.
Process of elimination isolated the crankcase ventilation heater shorted and causing the fuse to blow. Citroen deny this model has one. It doesn't appear to do anything so was disconnected. Fuse replaced, dash warnings gone.

200 miles later, no further faults found.

Total cost : over £800. Thanks Citroen.

Haynes autofix was no help because it has no full circuit diagram.

That's a pity but unfortunately that's the way manufacturers are going today.

Look up "The farmers Vs John Deere and the 'right to fix' laws" in the U.S.

Manufacturers are now "closing shop" on proprietary information forcing you deal only with them and forcing corner repairers out of business. This allows them to charge whatever they want to repair your stuff! The closest you will ever get, is to pay for a subscription to the manufacturer for access to this information.

The circuit diagram for a PSA car is NOT available to you unless you are repairer business. It is not available to "Joe Average". It is available via a subscription to a repairer but that repairer might only need it for 1 car during the subscription period. Not good business sense for the repairer!

"The French Car Forum" asks for a 'donation' from posters who request parts information to cover the required subscription to gain the information.

At least a good fault finding technique led you to the problem. Good work.

Ah yes, right to repair - can't come soon enough. Circuit diagrams should be freely available - and come with the car IMO.

Hello everyone,

Thanks for this valuable information! I have a Citroen c3 II (sc) with a 1.6 VTI engine and im getting the same 3 engine faults as you have mentioned. Also the f5 fuse keeps blowing. I am looking for the part you described that is causing the problem (crankcase ventilation heater element). Where is this part exactly? Is it at the back of the engine under the intake manifold (a brown plug)? Hopefully you can help me. Thanks in advance.

I think you are right. The crank case ventilation pipe clips into the rocker cover on the back left hand side of the engine then disappears around and under the inlet manifold. The plug should only have 2 pins.
Good luck, I have just worked on a Peugeot 207 and access to the back of the engine is very limited! The only access is from under the car and even then the sub frame and LH drive shaft are in the way!
I don't have access to a circuit diagram but that blown fuse may be causing your other faults.
You could try disconnecting the plug and replacing the fuse. Then see if the fault codes go away. Of course you will still have the PCV heater failure fault but it's just to stop the PCV freezing up in cold climates.