codigo p1400

hola amigos tecnicos, tengo un focus 2001 y tiene el codigo del sensor pdef y la verda me confundo con este problema por favor ayudenme a eliminar este problema, gracias de antmano.

Ford Number P1400
Type Powertrain - Manufacturer Controlled DTC - Manufacturer Controlled
Description DPF EGR Sensor Circuit Low Conditions

Cause Key on or engine running, then the PCM detected that the DPF EGR sensor circuit was less than 0 2v Scan Tool Tips. Monitor the DPF EGR PID for a signal below 0.2v.