I know this has been asked to death but here goes.
In the past year I've gotten the 1689 code at random(or maybe not)
The first time was right after I replaced the lift pump
The second and third time was shortly after I changed the fuel filter
The second and third time it was accompanied by a 0336 code(crank sensor)
Replaced crank sensor after second time.
When this happens the truck just shuts off,I clear the code,it cranks up and I go another four months.
The truck has great power,plenty of fuel(smoke),good boost, and starts if you LOOK at the key! No problems whatsoever.
The stock VP44 has 155k miles on it and I dont mind replacing it IF I HAVE TO, but if I dont I'm gonna keep on trucking! The truck has never seen low fuel pressure(I change the lift pump pretty often!)
Could an air pocket cause this? Does the Crank sensor and lift pump share a connecter in the wiring harness?
If I have to clear codes a few times a year it doesnt bother me,just dont want get stuck on the side of the road! Any help is greatly appreciated.

 

if i were in your shoes i would be replacing the vp 44.... 1689 is a code you don't want to see, "no communication between ecm and injection pump module" "data link failure
between ECM and fuel injection pump.low power,engine derated, or engine stops"
if you don't change it while it still runs, expect to do it on the side of the road or have it towed....... been there, done that