C450 P-31

[tarzak911]

this is your resolution as i had the same problem on c350 the black and cyan sensors connectors are not properly marked look the same...well done..it took me week to discover this......

[edmund]

Guys we had the same problem and it was resolved !!!
the sensors you are replacing are the phase correction sensors
there are two for the black tank and two for the C,M,Y COLOUR DRIVE SYSTEM
TWO SENSORS EACH
please check the harness plugs
both the black drive and the colour use a six pin connector and a fault could be easily made by swapping them around and P31 code appears
swap the connectors back
IKf memory service me the black harness has a blue plug and the colour white

[edmund]

please be careful when doing any harness changers on this model(C351) with the C450 the P31 problem the harness is straight forward .However with the C351 the the phase sensor harness has blown the PWB-M so be careful

[pepito17]

Hi
I have P-31 and replaced the sensors (PC11/PC36) , but
The code pops again ,only when making B/W copies. what can I do , please Help me!