P0191

DTC P0191: Fuel Pressure Sensor Range/Performance Problem

1. Inspect the vacuum hose routing of fuel pressure regulator P2 for leaks, restrictions or misrouting.

Is the hose OK?

YES - Go to step 2.

NO - Correct as necessary.

2. Turn the ignition switch ON (II), then check for fuel leakage.

Is there any fuel leakage?

YES - Check the fuel line routing of the entire fuel system.

NO - Go to step 3.

3. Start the engine. Hold the engine speed at 3,000 rpm without load (in Park or neutral until the radiator fan comes on.
4. Raise the engine speed to above 3,000 rpm, then check the fuel pressure sensor with the HDS or a scan tool.

Is 0.5 V or more indicated?

YES - Go to step 5.

NO - Do the troubleshooting procedure for DTC P0192.

5. Let the engine at idle, then check the fuel pressure sensor with the HDS or a scan tool.

Is there 2.33-2.93 V?

YES - Intermittent failure. The system is OK at this time.

NO - Go to step 6.

6. Turn the ignition switch OFF.
7. Substitute a known-good fuel pressure sensor.
8. Start the engine. Hold the engine speed at 3,000 rpm without load (in Park or neutral) until the radiator fan comes on.
9. Let the engine at idle, then check the fuel pressure sensor with the HDS or a scan tool.

Is there 2.33-2.93 V?

YES - Replace the fuel pressure sensor.

NO - Replace fuel pressure regulators P1 and P2, or update the PCM if it does not have the latest software, or substitute a known-good PCM, then recheck.
If the symptom/indication goes away with a known good PCM, replace the original PCM.