Exeo secondary electric water pump issue

[Evo4jon]

Hi

I have an Exeo with the 2.0 tdi 170 CAHA engine -40,000 miles, 59 plate.

I ran VCDS just out of curiosity really and it showed that I had an "open circuit" fault on my secondary electric water pump. I checked the pump for resistance and it appeared to be open circuit so I ordered and fitted a replacement pump.

Tested with VCDS after a few good long runs where the engine should get upto temp OK and there is no error code since I cleared it last and fitted new pump.

BUT...

The new pump doesn't seem to get hot and the pipes to and from it don't get very warm either which makes me think it's still not running. After a long run if I can open the bonnet and listen / feel the pump, but its not running ?

I read somewhere that the pump is for the EGR cooler circuit in order to cool the gasses before they enter the inlet via the EGR valve. Another forum thread (Audi) seemed to indicate that it was also used to bring warm coolant from the EGR cooler to the heater matrix in order to facilitate a quicker warmup in the cabin... I also thought it was a run-on pump which should be triggered when the car is at rest after a long journey to prevent heat soak in the EGR cooler which may cause splitting or damage to the cooler.

So I guess my question is, does anyone out there have an Exeo and could they tell me what their experiences are with the secondary water pump? or is there a knowledgeable person who can point me in the right direction or enlighten me as to when this pump is supposed to work ?

Many Thanks

 

[Evo4jon]

OK I have sussed that its working. I am new to VCDS and wasnt sure how to go about testing further once I had cleared the fault code and replaced the pump. The code not coming back was probably all that I needed to know in hind sight.

I connec ted VCDS and ran the output test for the egr cooler pump. This ran the pump and I was able to feel it working when I place my hands on it and hear water flowing back into the expansion tank. SO... Its working after all and there is no further investigating to do.

That Output test is brilliant

Jonathan

 

[Evo4jon]

If your hoses to the secondary pump are not as hot as the regular hoses, then suspect that your EGR cooler may be blocked!.. I will post my findings of this !!!!

 

[Fmxvxx]

Or You have an airlock.

 

[Evo4jon]

Or You have an airlock.

Possibly, but when I ran the pump via VCDS there was circulation back into the expansion tank which ruled out an airlock in my case.

Plus its unlikely to airlock as the other pump does contribute to general flow and the location of the secondary pump is right next to the expansion tank - which "sees" flow like most VAG cars.