Got a call from a guy with a 24 valve that would not start. He scanned the truck and come up with no communication between ECM and pump.

No recent problems with the truck but one year ago the lift pump went out and he replaced that. Truck has 200,000 miles, no modifications and well maintained.

Is his IP shot? How does he check if it is toasted? He says that there is power at the connection on the back of the IP. When he bumps the starter he can hear the lift pump run.

Any help appreciated.

 

Without the breakout box that basically isolates the pump from the computer, it will be hard to tell for sure. They make a tool ( breakout box ) that takes the place of the computer and such and will let the truck run if the IP is o.k. If it still doesn't run, IP has failed. I'm gonna bet it's the IP with the no communication code.

 

Thanks VZdude. I'm thinking that it sounds like his IP but don't want him to drop $$ on a new pump unless he has to.

Paul

 

Update: He was able to tell me the code was 1689. He has checked fuel relay and connections. What is next best step before replacing VP?

Thanks.

 

Has he checked for fuel thru the filter? Does he have a fuel pressure guage? He can open a couple of the fuel lines to the injectors and see if there is fuel there.

 

1689 no communication between ecm and injection pump module

in lamens terms "pump is toast" as far as i know.

 

1688 means replace it, 0216 means your going to replace it soon. 1689 could be in the wiring harness between the ecm and pump, or bad pump. or bad ecm, I would check out the wiring first, but you probley going to change it. I would not like to change it and it still not start.

 

After I got the 1689 code from him that helped me to do better searches and it seems that a lot of guys got that code and it could be anything from bad connection, relay or fuse or that the pump is gone.

I told him about checking for fuel flow at an injector and the relay so he will check these today. His brother is a diesel mechanic but works on OTR semi's so isn't as familiar with the VP44.

I read one post where a guy replaced his pump ($$) and still had the 1689 code so it doesn't seem real clear cut that it is gone but a good possibility. Hard to stomach a $1000+ experiment to see if that is it though.

Thanks for suggestions. I'll post updates on progress.

Paul

 

I would check the fuses and disconnect and re-connect the harness before buying the IP, but I am afraid that it is the VP44. I hear the ECM nearly never fails.
-P