2000 Audi S4 HFS-3 not spraying ::CORRODED PUMP::
 

Just as title says im having problems with my HFS-3 system not spraying. It was spraying before but for some reason has stopped working. I am pretty sure its wired correctly because as I stated it was working correctly before. When I turn the ignition key to on position the yellow water light comes on for a few seconds then the red w.injection light comes on and the gauge fully lights up. When I start the car the flashing light in the controller box flashes like it should. I have also tried re-priming the system. Any help is greatly appreciated.

Re: 2000 Audi S4 HFS-3 not spraying
 

Can you check the following:

1. Remove the 6mm hose from the FAV. Manual trigger the system. Tell me if water is gushing out at a good rate.

2. Reconnect the 6mm hose to the FAV.

3. Remove the 4mm hose from the FAV. Manual trigger the system. Tell me if water is gushing out at a good rate.

Re: 2000 Audi S4 HFS-3 not spraying
 

Removed the 6mm hose and manual triggered the system and water is not coming out like it did before.

Re: 2000 Audi S4 HFS-3 not spraying
 

Good find.

Next step check:

4. The pump is running under manual test linked.
5. If there is no pump activation
6. Check the fuse between the 15A relay and pump.
7. Check if there is 12V across the thin red and blue wire under the relay.
8. If there is 12V present and the pump is not running, bridge the two thick red wires.
9. If the pump comes on, you have a faulty relay
10 If the pump still does not come on after bridge the two thick red wires
11. Check if there is 12V across the two-pin connector to the pump.
12. Check the black wire is grounded properly.

That is all for now.

Re: 2000 Audi S4 HFS-3 not spraying
 

I am not getting 12V across the thin red and blue wire under the relay. That was assuming i needed to put one lead on the red and one lead on the blue?

Re: 2000 Audi S4 HFS-3 not spraying
 

Yes, one probe on each colour.

You need to link the TST to see the 12V

Richard

Re: 2000 Audi S4 HFS-3 not spraying
 

What do I need to link to TST to see the 12V?

Re: 2000 Audi S4 HFS-3 not spraying
 

I dont see anything that says TST on the control board

Re: 2000 Audi S4 HFS-3 not spraying
 

Ok, in the manual trigger/test mode i am getting just under 12V(11.64). The battery has over 12V

Re: 2000 Audi S4 HFS-3 not spraying
 

It is OK to see 11.64.

Please continue with the following tests:

8. If there is 12V present and the pump is not running, bridge the two thick red wires.
9. If the pump comes on, you have a faulty relay
10 If the pump still does not come on after bridge the two thick red wires
11. Check if there is 12V across the two-pin connector to the pump.
12. Check the black wire is grounded properly.