P1689- no comm between ecm and injector pump
What does this mean?

 

Unfortunately, the 1689 DTC usually means that the VP44 ECU likely has some type of damage to its PC board causing a degree of lack of continuity in it.....the bottom line in this case is usually that the VP44 will have to be replaced since the piggybacked ECU is not independently serviceable. An inspection of the ECU connectors might yield something but I doubt it - usually the board is punched.