Does anyone know, why my ecu keeps the fuel pump on high voltage? This happened when I switched to open loop (using pheriphery bit) and idled the car between 2000-2500rpm some times (tried different injector scaling values).. Thought it was relay related but logged the fuel pump low/high and it stayed at 0, which means high voltage. I disconnected the battery for about 5-10 minutes and then the low/high worked fine again. I tried first to switch back to closed loop but it didn't fix the problem.

This happened yesterday and today and disconnecting the battery helps. If I disconnect it for a minute or so, it doesn't help, so needs some time. Does anyone know, why the ecu (96940011 Evo8 2005MR) works like this?
The car is still on maf and and using stock maf scaling, Bosch ev14 1500 injectors, e85 and 835 scaling.

 

Look at the fuel pump control table. It could be that your getting enough load at that RPM to trigger the pump high mode. Keep in mind there is a load hysteresis. So once the pump is triggered high speed load needs to drop below (Table Value - Hysteresis value) to trigger the pump back into low speed.

 

Thanks for the reply,

It is odd that it doesn't jump to high voltage when running 2-2.5krpm. It does it after shutting down and at the next start as it should but it should go to low voltage in a moment but mine doesn't do it.

 

This happened on closed loop too, so it's not open loop related. Idled the car with different scaling values 2-2.5krpm and then stopped the engine and got back to the "normal" scaling value. Started the car and drove and I noticed the high voltage was on again on easy cruising. Drove for a while and it went back to low voltage after couple of miles.

 

hi. do you fix this issue? have same problem, but get always low\high pump speed ecu pins active.