Webasto Thermo Top V Dose pump problem.

[eatorb]

Hi,

I got a 2009 vw caddy with an auxiliary heater. I have done a 6 speed swap and cluster swap with cruise control. So I had some things recoded. Maybe that's the issue?

Before I started messing with the heater I had a fault code on the burner and flame arrest, we tested the water and fuel pump and they worked fine.

After changing the burner the dose pump clicks and pumps fuel when tapping 12v to the 8-pin connector at the heater. Still the heater set Fault code 02456 - Line Filling and one more about shortage to power. Ive tried four different heaters. All set same fault codes. The pump is 4.7 ohms. (VW says 5ohms +-10%). I have 10.5v at the pump when doing the component test. The wire from heater to pump is good, and ground is good.

I did test a second fuel pump with a warning label (Do not use with thermo top v) tried it anyway. And with the same fault codes.

Can the fuel pump still be the problem?