Circuit Description
The engine control module (ECM) monitors the fuel rail pressure via a fuel rail pressure (FRP) sensor. When the fuel rail pressure is high the signal voltage is high. When the fuel rail pressure is low the signal voltage is low. If the fuel rail pressure is not above the lower limit for the sensor, diagnostic trouble code (DTC) P0192 will set.
Conditions for Running the DTC
| • | DTC P1635 or P1639 are not set. |
| • | The ignition is ON. |
Conditions for Setting the DTC
The ECM detects the signal circuit is less than 1.2 MPa.
Action Taken When the DTC Sets
| • | The control module illuminates the malfunction indicator lamp (MIL) when the diagnostic runs and fails. |
| • | The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Freeze Frame/Failure Records. |
| • | The control module limits fuel injection and fuel rail pressure. |
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
The numbers below refer to the step numbers on the diagnostic table.
-
Tests for the proper operation of the circuit in the low voltage range.
-
Tests for the proper operation of the circuit in the high voltage range. If the fuse in the jumper opens when you perform this test, the signal circuit is shorted to ground.
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
Schematic Reference: Engine Controls Schematics | ||||
1 | Did you perform the Diagnostic System Check-Engine Controls? | -- | Go to Step 2 | |
2 |
Does the scan tool indicate that the Actual Fuel Rail Pressure parameter is within the specified range? | 1.2-1.9 MPa | Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems | Go to Step 3 |
Does the scan tool indicate that the Actual Fuel Rail Pressure parameter is less than the specified value? | 175 MPa | Go to Step 4 | Go to Step 5 | |
Test the signal circuit of the FRP sensor for a short to ground or high resistance. Refer to Testing for Short to Ground and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 7 | Go to Step 6 | |
5 | Replace the fuel rail pressure sensor. Refer to Fuel Injection Fuel Rail Fuel Pressure Sensor Replacement . Did you complete the replacement? | -- | Go to Step 7 | -- |
6 | Replace the ECM. Refer to Engine Control Module Replacement . Did you complete the replacement? | -- | Go to Step 7 | -- |
7 |
Does the DTC run and pass? | -- | Go to Step 8 | Go to Step 2 |
8 | With a scan tool, observe the stored information, Capture Info. Does the scan tool display any DTCs that you have not diagnosed? | -- | System OK | |
