Hey everyone, new paying member here, having issues with my truck and looking for some guidance. My truck is an 01 24v HO. I have had zero drivability issues since purchasing it about seven years ago until yesterday. Driving down the road as per normal when the engine just suddenly shuts off. I coasted it to the side of the road noticing the check engine light was on so immediatley cycled the key to view codes. I was met with P0230, P1688 and P1689. Luckily I was semi close to my shop so had some good Samaritans help me push it the rest of the way there. The truck is a crank but no fire scenario. I first turned the key on and confirmed the lift pump started and primed. I then bumped the key to allow the lift pump to run and opened the schrader on the injection pump inlet. Fuel was present and spraying out as I have always seen when bleeding after a new filter install. I then started checking the lift pump and injection pump circuits with some strange results. Pin 2, component side of lift pump to ground showed open limit on my ohm meter. Pin 2, harness side of lift pump showed the same result. Spent some time messing with that to make sure I was getting good connection to the block when testing, no change in results. In frustration I moved on to the injection pump. Confirmed voltage on injection pump connector of 12.5 volts. Removed ECM connector and resistance tested pin 13 (Datalink +) to the ground pin on injection pump connector aswell as battery ground. Both results from this were also open limit on my ohm meter.... At this point I was starting to doubt my meter, checked resistance from injection pump connector ground to battery negative, .6 ohms so meter was functioning. Am I looking at a severed harness? Where should I go from here? I am just assuming the meter saying open limit on all of these circuits would mean the wires are damaged / broken. It seems unlikely to me that they would all fail at the same time but I guess stranger things have happened.

 

Hopefully all of the wisdom here can help me figure this out!

I like W-T's name for our lift pumps, ''Peanut Whistle'' That's dang funny for some reason

@Basranabread, good job using the test procedures you selected.  You drew an informative conclusion.  Let us know when you get the new pump installed.

 

- John

Replacement pump arrived yesterday evening and I installed it immediatley and took the truck for a test drive. I'm happy to report it ran absolutely perfect and even at wide open throttle I could not notice the fuel pressure gauge dropping at all. Happy to finally have this solved and thanks everyone for your input and help!