The engine trouble B1709 Code is related with the car engine and if you want to avoid all problems from the engine, it is necessary to solve the problem as soon as possible. The code has different meanings according to the vehicles. The dictionary meaning of the code may not have any relation with your car engine problem but you need to know B means Body Code Problem is antilock brake system, electronic suspension and steering systems. 1 means MFG – Manufacturer Specific. 7 means Auxiliary Emission Controls. 0 for IC Circuit High Voltage and 9 means Kick-Down Switch Failed Short.