Agreed. Change both pumps while you are in there considering the labor involved to get in the tank in the first place.

 

I am having both pumps replaced as the engine management light comes on and this results in an MoT failure in the UK. OBD2 code says secondary pump relay failure. I have swapped the relays around and it makes no difference. I assume it is failure of the secondary pump. The garage want to change the fuel pump module. I cannot see this is part of the normal procedure when replacing both fuel pumps. IS it necessary? If so where is it?

 

I'd only change it if known to be bad.

 

Curious - what are the last 6 characters of your VIN?

Fuel pump module doesn't appear until the 4.2L, unless the garage means something else.

 

This is such a old thread, but worth keeping alive regardless, imho, since it’s full of good information.

once the owner has determined both fuel pump are working (4.0) it’s a good practice to have several maximum acceleration runs at least weekly if not every time the car and driver have the opportunity. Regular activation of both pumps is good for the car, and the driver too.
And reduces the chances of losing pump #2 due to inactivity.

Z

 

If you have two fuel pumps, you do not have any fuel pump module. There are just two relays that is turned on and off directly by the ECU.
The fuel pumps and relays can easily be tested.
I think you have an another problem with your car, and that the ODB scanner used is giving you the wrong fault for the code.
Please give us the actual fault code. If I remember correctly it can be one of the O2 sensors that are faulty, in that case the code will be in the P013x range
Edit:
I found it!
If you have the P1646 code, that is "ECM HO2 sensor control malfunction - bank1 upstream". This code is reported as Fuel pump relay malfunction on earlier cars.