Activating the rear washer sprays the front

[thefunkaygibbon]

My 2017 C3 has developed a fun one today, when activating the rear washer, the front windscreen is sprayed, but the rear wiper activates. Using the front washer works as expected.

Faulty pump? Blocked line? Something else? Anyone experienced this before?

[GiveMeABreak]

Could be multiple causes, not least:

• Pipes inverted on the pump
• Front and rear screen wash pump
• Built-in systems interface
• Switch module at the steering wheel

Has the pump been replaced or the pipes removed from the pump recently?

Try a BSI Reset / Battery Disconnect / Reconnect Procedure first of all to see if that fixes it.

[thefunkaygibbon]

VIN - VF7**************[VIN obfuscated, can be read by forum staff]

There have been no work carried out on the pump at all within the last few years.

[GiveMeABreak]

Sorry, not sure what happened there, I must of pasted in some text re the VIN! Not needed, but leave it there in case of a later query.

Try the reset first in any case as this can sometimes clear glitches.

[xantia_v6]

If this model has a single dual-outlet pump, then it is probably the pump failed.

[myglaren]

There is a flapper valve that can fail in some pumps.

Some models also have the rear wipe activated if you engage reverse.

[wheeler]

If no one has disturbed it almost certainly a pump failure. I've replaced loads of them for this fault on various different PSA cars over the years.