P0193

DTC P0193

CIRCUIT DESCRIPTION
The fuel rail pressure (FRP) sensor is a pressure sensor. The powertrain control module (PCM) supplies about 5 volts on the FRP sensor reference voltage circuit. The PCM also supplies a ground circuit and a signal circuit to the FRP sensor. When the fuel rail pressure is normal, the FRP signal voltage rises to near 2.5 volts. If the fuel rail pressure increases, the FRP signal voltage increases. The PCM uses the FRP sensor information in order to adjust fuel trim.

This DTC sets when the FRP sensor signal voltage is more than the calibrated value.

DTC DESCRIPTOR
This diagnostic procedure supports the following DTC:
DTC P0193 Fuel Rail Pressure Sensor Circuit High Voltage

CONDITIONS FOR RUNNING THE DTC
- The engine speed is more than 100 RPM.
- DTC P0191 is not set.

CONDITIONS FOR SETTING THE DTC
- The FRP sensor signal voltage is more than 4.95 volts.
- The condition exists for at least 2.5 seconds.

ACTION TAKEN WHEN THE DTC SETS
- The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
- The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.

CONDITIONS FOR CLEARING THE MIL/DTC
- The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
- A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
- A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
- Clear the MIL and the DTC with a scan tool.

TEST DESCRIPTION

Step 1 - Step 12:

Step 13 - Step 14:

The numbers below refer to the step numbers on the diagnostic table.
2. This step determines if the condition is present.
4. This step determines if a shorted signal circuit is the cause of the condition.
5. This step determines if a shorted 5-volt reference circuit is the cause of the condition.
6. This step determines if an open sensor ground circuit is the cause of the condition.
10. The Fuel System Diagnosis should be performed prior to replacement of the FRP sensor. The fuel system diagnostic procedure will determine if excessive fuel pressure is the cause of the condition.