P018D-FUEL PRESSURE SENSOR CIRCUIT HIGH
Theory of Operation
The Powertrain Control Module (PCM) provides a 5-Volt supply to the Fuel Rail Pressure Sensor (FRPS). The PCM also provides a ground on the sensor return circuit. The Fuel Rail Pressure Sensor provides a signal to the PCM on the Fuel Rail Pressure Sensor Signal circuit. This sensor signal voltage changes based on the pressure in the fuel rail. The PCM will detect a low signal voltage at low rail pressures. The PCM will detect a high signal voltage during high rail pressure conditions.
When Monitored and Set Conditions
This diagnostic runs continuously when the following conditions are met:
- With the ignition on.
- Battery voltage greater than 10.4 volts.
- The Fuel Rail Pressure Sensor (FRPS) signal circuit voltage is above a calibrated threshold for a certain period of time.
- The MIL light will illuminate.
FRPS SIGNAL CIRCUIT SHORTED TO VOLTAGE
FRPS SIGNAL CIRCUIT OPEN/HIGH RESISTANCE
FRPS SIGNAL CIRCUIT SHORTED TO THE 5-VOLT SUPPLY CIRCUIT
SENSOR GROUND OPEN/HIGH RESISTANCE
FUEL RAIL PRESSURE SENSOR <<< most likely cause
POWERTRAIN CONTROL MODULE (PCM)