My ML stalled while driving and I to have it towed home. When I turn key it will crank but not start. The low pressure transfer pump does not audibly prime when you turn on key, which I was able to hear before this issue. I am not getting fuel to the high pressure pump. I tested the low pressure pump with 12 volts directly while cranking and it did send fuel to high pressure pump but the fuel rail never pressurized, so I assume the ECU is cutting fuel to both the high and low pressure pumps. The codes I am receiving P0091, P2118, P0003, P0560.
New info, used a different scanner N74 and N94 codes pressure and quantity valves show a short from positive to ground so I disconnected them. Now the transfer pump works and the two valves show an open circuit. Checked the resistance of the valves-3 ohms across the coil. Checked each side to ground no reading so I assume no short. Tested with 12 volts and I can hear the valve click open. Can anyone tell me how the ECU determines it has a short?
