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Headlight washers not working.

nicholasedgley

PCGB Member
Member
I have a 2005 997 Carrera S. The headlamp washers have stopped working. The fuse is intact. The dedicated headlight washer pump functions when tested by connecting it directly to a power source. I swapped the relay with a known good relay and also tested the operating switch on the wiper control stalk. I have also established that the headlight washers do not work with every tenth windscreen wash. So other than an unlikely wire break it is looking increasingly like a software issue.

Despite extensive internet searching I have only found one reference to a similar problem and that was on the rennlist forum where a helpful owner had responded to a poster with '....I had non-fuctioning headlamp washers and heated seats at the same time. The solution was a handover(sic) reset on PIWIS.'

I am not sure whether that poster meant a 'hard reset on PIWIS' if he/she didn't then what is a 'handover reset'?

I do not have heated seats.

I have an iCarsoft i960 OBD reader and having spent some time trawling through all the options it offers and it shows me things like the values for the intermittent wiper delay values and other values for various of the car systems but nowhere can I find anything related to the headlight washer system.

So my thoughts are that the relevant electronics in the car have 'forgotten' the car has headlight washers fitted.

Anybody any suggestions or am I going to have to employ the services of someone with the correct piece of kit to re-program the car as required?
 
Have you eliminated a leak in the system as a potential cause?
The washer system is pressurised and will not work if sufficient pressure has been lost.
Regards,

Clive
 
I think you have diagnosed the fault correctly. This era of car can lose knowledge of heated seats / headlight washers if the battery goes flat in a certain way. Not common, but I have seen it a few times.

The ‘handover‘ is a phrase used for the process when the car is bought to life after vehicle assembly. A specialist or OPC can re-run this for you and it should fix the fault (Although I personally find the handover process difficult!.

KR Lee
 
Hi,

Are the headlights switched on when you are testing the function by using the dedicated button?

Marc
 
Hi

If the battery has been recently disconnected or lost charge then it is quite likely to need a vehicle handover procedure completed via PIWIS - this is a service procedure that causes a resetting of the communication channels in the car that allows the modules to talk to each other correctly and return to normal operation - any other brand would have called this a manufacturing defect!! It only seems to effect the 9*7 models.

Anyway it can only be done on PIWIS to my knowledge, none of the other OBD software has the feature that I have come across.

Thanks
 
Have you eliminated a leak in the system as a potential cause?
The washer system is pressurised and will not work if sufficient pressure has been lost.


I was unaware of that and will check but I have not seen any suspicious loss of fluid so think it unlikely.

This era of car can lose knowledge of heated seats / headlight washers if the battery goes flat in a certain way.


This is likely. I do not use the car as a daily car and I recently fitted a forward facing video camera. It caused the battery to go flat a few times because it has a motion triggered parking mode and also the battery was failing. I fitted a new battery and now leave the car on a maintenance charge most of the time. I suspect the problem occurred during one of the times the battery was flattened.

Are the headlights switched on when you are testing the function by using the dedicated button?


I did take the precaution of reading exactly how they functioned prior to investigation but thanks for the suggestion.

If the battery has been recently disconnected or lost charge then it is quite likely to need a vehicle handover procedure completed via PIWIS - this is a service procedure that causes a resetting of the communication channels in the car that allows the modules to talk to each other correctly and return to normal operation - any other brand would have called this a manufacturing defect!! It only seems to effect the 9*7 models.

Anyway it can only be done on PIWIS to my knowledge, none of the other OBD software has the feature that I have come across.


Unfortunately that is the conclusion I was coming too.


Thank you all for your useful suggestions and comments. I will post the outcome when I get it sorted.


 
My C2S 2005 doesn’t have the jets connected, something the previous owner had removed. Paragon think this is not unusual. Unless you are doing the Paris Dakar rally a decent clean once a week will work...
 

An update for anybody interested.

I visited a friend's workshop and borrowed his Snap-On Solus Ultra diagnostic box. It has the ability to test various systems including the headlamp washers. The diagnostic box activated the headlight washers and also confirmed the steering column switch function. This confirmed my suspicions that the car software needed addressing.

After a few fruitless telephone calls I found an independent who was very helpful on the telephone and I took the car over to them this morning. Great set up on a small industrial complex, friendly and attentive staff and 15 minutes later they had reset the software to tell the car it had headlamp washers! What was especially pleasing was that with an hourly rate of £70 per hour they just charged me for 20 minutes labour which I was a very pleasant surprise. They have just gained a future customer!

For anybody in the looking for a good independent in the south of England they are Autofarm

Thanks for the suggestions made when trying to solve this problem.
 

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