Isthe fuel pump turning on? Is the fuel pump fuse bad? Is the fuel pump relay fuse bad? Is there a poor connection on the fuel pump? Is the fuel filter clogged? Are the fuel injectors clogged? voltageis then provided through the fuel transfer pump relay switch contacts to the fuel transfer pump. Fuel Transfer Pump On The body controller will turn on the fuel transfer pump (if pump is off) when all of the conditions below are true. • The Fuel_Draw_Level value Œ 6% is less than 80% Full Fuelpump relay: R3: Oxygen sensor relay or: EKP and start detector relay or: Wiper motor relay or: Engine control module relay or: Secondary air pump relay or: Delivery pump relay (diesel) R4: Horn relay: R5: Fog light relay: R6: High beam relay (to 8/93) or: Low beam relay (as of 9/93) R7: Thefuel pump relay is the middle relay on the passenger side fender. One of the wires connected to this relay is a dark green wire with a white tracer, located in pin A1 of the fuel pump relay wire harness socket assembly. Yes you are correct, the relay and the oil pressure switch have to be bad in order for the fuel pump no to run. I CP4High Pressure Fuel Pump Failure. CLICK HERE to purchase our LML CP4 High Pressure Fuel Pump Failure Kit. The 2011-2016 Duramax suffers from a high pressure fuel pump issue unique to this year range. Failure of this CP4 pump is usually catastrophic, causing instant contamination of the entire fuel system with metal particulates. Isthe fuel pump relay switching off the fuel pump? When you turn the key to the on position, do you hear a click and the pump shut off? If not, the relay is bad and needs replaced. If pump keeps running it will flood engine. Posted on Apr 20, 2009. Helpful 1 ; Not Helpful; Comment; Flag Forfueling issues are bad fuel, too much fuel (black spark tips) or starvation, finding this is easy, try to keep engine runing with hand sprayed test fuel. 42 ASD fails up to 1998 or can mean the Fuel pump relay output is DEAD. See FSM for details. (not yours) 43 Dead spark (primary side) DTC errors (P0351) this is the spark coil 8xnQd.

when a fuel pump relay is bad