More info, found this code site
OBDII diagnostics. Trouble code definition for code P1684. Causes of error P1684 Also, "driver" in this context refers to an output of an electronic module. Driver 5 = chip 5 , Line 4 = 4th output of that chip.
Definition of check engine code P1684:
Chrysler/Dodge/Jeep:
The battery has been disconnected within the last 50 starts
Citroen/Peugeot:
Metering Oil Pump Position Sensor Circuit Malfunction
Fiat:
Motorised throttle(plausibility)
Ford:
Metering Oil Pump Position Sensor Circuit Malfunction
GM:
Driver 5 Line 4
Honda:
Throttle Valve Return Spring Performance Problem
Mercedes:
Metering Oil Pump Position Sensor Circuit
Mini:
Electronic throttle control monitor level 2/3 - clutch torque min error
Plymouth:
Battery Disconnected Within Last 50 Starts
Volkswagen/Audi:
Contr. Unit Programming Communication Error
Volvo:
Contr. Unit Programming Communication Error