Kalashnikov

I changed my IC to CM30 and wanted to make a post for people with 2006 cars about things that I came across as there is a ton of conflicting information on the web about the pump operation and how it is controlled.

First, there is a fuse, it is #4 in the trunk, driver's side; factory is 7.5a, I put 15a as a replacement. There is also a relay, it is in the A spot in the same fuse box in the trunk. The relay in the E55 AMG is in the fuel pump relay position on the non-AMG cars. It is a smaller black relay. See picture for more clarity.

Pump function and activation. My car is an 06, so this may be different for other model years. I've read countless posts that say that pump is activated when ignition is ON, or when engine is revved past 2,000 RPM, or when coolant temperature is at operating temp. None of this has triggered my pump to come on. Ignition ON- no go, revved engine past 2,000 and held at 3,000 when engine is at operating temp- no go, car being at operating temp- no go. What triggered the pump activation was accelerating hard briefly to engage the super charger. Once the super-charger was engaged, pump immediately came on and stayed on until engine was shut off.

Bleeding the pump is fairly easy. If you want to bleed it before starting the car, I used the battery jump box and connected it directly to the pump to bleed some air out. Then when pump is wired I had bleed for another 20 minutes with engine running. You will need about 3 feet of the clear hose, I think it is 3/8s of an inch on the ID.

I hope this helps other people changing their pump.

atoms

Very cool, those photos get the important bits. I've done this process once myself on a 2005 and activated the pump by shorting the appropriate relay. The hardest part was figuring out the correct one. Pictures help a lot in cases like these. Thanks for sharing.

lseguy

i found it near impossible to get alligator clips or wires onto the two tiny electrical pins on the pump. Was MUCH easier to simply jump the two relay pins in the trunk with a piece of wire. The diagram in the link below shows the two pins. (Red arrows)



While my job wasnt a pump replacement, it was a water pump job. So hoses off, water pump off, thermostat replaced, etc. Funny thing is, there were no bubbles when I bled my coolant pump. Once I pinched off the hose, plenty of coolant flowed from the clear line over to my expansion tank. But no bubbles. All perfectly smooth.

JoeJErnst

I'll add my two-cents to the discussion. Whenever I want the pump to come on, which is usually between rounds at a race, I would just blip the throttle wide-open for a split second with the car in Park. If you press the accelerator down against the button that sits on the floorboard it will activate the pump, and it will continue to run until your IAT's get down to 68° .

You can also use STAR to activate the pump, which is nice when in the garage because the car doesn't need to be running to bleed the system.