Archived P1689 code ??? any fixes

[Short Stack]

P1689 Code any Ideas for fix? No comunication btwn Ecm & Injection pump?

 

[rkressg]

What are the truck symptoms? If you are driving and the truck just de-fuels for no reason, then runs normal again, then I would bet my lunch on replacing the VP-44.



If you have the pump wire tapped, you can try and clean the tap connections, there probably is corrosion in the wiring in the VP-44.



Just prepare your self, chances are good that you will need to replace the VP-44.





One other thing, check pins 1-2 on the pECM (harness on VP-44) to pins 13,23 on the ECM (Harness on EMC). These two wires are paired together, shielded, and twisted ~=2tpi to keep out electrical noise. If this shielding becomes worn, than you have created a point of electrical noise to enter the circuit, which could cause the p1689 error (but I doubt it)



-Rich