P1641 FORD: FUEL PUMP DRIVER MODULE FAULT CONDITIONS
POST UPDATED IN May, 2023
P1641 FORD: FUEL PUMP DRIVER MODULE FAULT CONDITIONS
The fuel pump is enabled for a few seconds after turning the key to the ON setting. With this, the pump is primed and the fuel system is pressurized. In case the engine does fail to crank or the key is in the ON position, the Powertrain Control Module (PCM) deactivates the pump according to a timing schedule set by the manufacturer. For the fuel pump to operate, the PCM must receive signals from various sensors indicating that the engine has started and is operating regularly. In this sense, the most vital signal is from the engine speed sensor, which relays the engine RPM.
When the ignition circuit is turned on, a dedicated relay that delivers power to the fuel pump is also turned on. With this relay, a low amperage circuit is used to close a high amperage circuit through the activation of an electromagnet, which in turn drives a moving contact point with a stationary live contact point. This whole process indicates that the PCM electronics, being delicate, does not require sending high amperage current to an electrical consumer, which in this case is the fuel pump.
However, when there is prolonged use, the contact points of the high amperage switch in the relay may be damaged to the point of burning out and as an end result, the contact is no longer usable. Once this happens, the PCM interprets this as a circuit fault and will set the P1641 OBDII diagnostic code.
The reasons for which the P1641 OBD2 fault code is set are:
The steps to follow to correct the DTC P1641 OBDII code are: