Archived LP Problems

[klaybus]

No me... . But a fellow 99 owner. I'm in Tokeland, WA for the 4th of July & a fellow 99 owner\RVer broke down on their way to the RV park. He stated that he stopped for fuel & when he went to start his truck it would only crank, no fire. His FP has been constant at about 14 psi prior to stopping for fuel. He fueled up, & he now has no fuel pressure. His pump is not getting any power what so ever. He test lit z& then metered his connection & nothing. I looked in my service manual & see nothing as far as relays on the Lp. He replaced his LP & it too isn't getting any power. Could his ECM have gone South? Anyone else experience this? He got 2 errors but could remember the code numbers. 1) lost communication from the ecm 2) something in regards to the LP... . Nothing on the VP (0216)

Any suggestions? He was able to get his rig home by applying a direct 12V to the LP but he's got a trip planned to Yellowstone this coming Friday. All help appreciated...



Clay

 

[Missouri Mule]

Should be relay/fuse in the PDC related to the lift pump. Though the ECM does supply power to the lift pump.

 

[B.G. Smith]

Should be relay/fuse in the PDC related to the lift pump. Though the ECM does supply power to the lift pump.

Yeah, the relay for the fuel pump is in the lower left corner of the PDC on 99. bg

 

[JLandry]

The ECM provides power directly to the lift pump. There's no fuse or relay for the lift pump external to the ECM. The fuse marked "FUEL PUMP" in the PDC is for the Bosch VP44 fuel injection pump.



If the ECM isn't providing power to the lift pump any longer, then there's either an open circuit in the wiring harness or the ECM has failed and requires replacement. Unfortunately it does occasionally happen.



Now assuming the ECM is otherwise working properly, in a pinch the lift pump can be supplied power from the truck's battery using a relay and fuse, with the relay controlled by a circuit powered when the ignition key is turned on.



Good luck,



John L.

 

[JGamble]

Was this individual running any new uprgades to the ECM? Quad Adren. box or otherwise that would have required to hook up differently upon installation, thereby maybe a loose connection? Im thinking possible ECM failure