2003 BMW 330 Problem starting under 40F

The problem is that I can't seem to start my car during cold temp and cold engine even after I've replaced the fuel pump which was recommended by the tech. It cranks but it won't turn over. So, basically, it may not have been the fuel pump having problem.

In the interim, I can start it if I turn off/on a few time before starting the engine. I'm afraid this might cause further damage somewhere down the road.

The tech did a measurement at the fuel pump and saying there's no signal coming from the DME most of the time during that the cold temp. Could it be the fuel pump relay? He recommended to replace the DME. I chose to exclude this info because I think he was just trying to get me to spend more money which may not solve the problem at all.

I'm trying to get second opinion whether to pursue with replacing the DME or try other cheaper alternative first.

Do you believe DME or any of its component can be temperature sensitive?

No, he's not.

For $50, I can send in via express mail to a place where they can run diagnostic on the DME. However, if they do find some defective components or needed to repair it, the maximum cost would be $475.

How do feel about DME remanufacturing?

What other option do you suggest?

I'm thinking of trading it in this summer if there's no fix since the car is paid off.

Hi Dr Hagerty,

OK. I found a few other owners having the same problem. Their common solution is the fuel pump relay.

I also verified that the horn relay is exactly the same as the fuel pump relay. I'll attempt to swap them around and try.

I read that the relays are located right behind the fuse panel for the 2003 330xi. The question is do I have to take the glovebox door off to access the relay? Or can I remove the screws holding the fuse panel? Or is there another easier way to access it?

Much appreciate it

Hi Dr Hagerty,

I did find a website showing how to take the glovebox apart to reach the relay area.

I swapped the horn and the fuel pump relay.

And drum roll please.

The car started this morning on the first start at 42 degrees F.