Fuel Pressure Regulator Control Inspection

WARNING:
- Fuel line spills and leaks are dangerous.
- Fuel can ignite and cause serious injuries or death and damage.
- Fuel can also irritate skin and eyes.
- To prevent this, always complete the "Fuel Line Safety Procedures".




1. Install the fuel pressure gauge.
2. Measure the fuel pressure under the following conditions.




3. If the fuel pressure is not within the specification, carry out either Inspection 1 or Inspection 2 as required, based on test results.

Inspection 1
1. Stop the engine.




2. Connect the SSTs to the data link connector 2 located under the driver side dashboard.
3. Verify that diagnostic trouble code No. P1250, P1252 is not displayed.
- If code No. P1250, P1252 is shown, carry out troubleshooting of the code No. P1250, P1252.
4. Start the engine and run it at idle.
5. Select the "SIMULATION TEST" function on the NGS display.




6. Turn the PRC solenoid valve No.1 from OFF to ON by using the "PRC V" and check if the fuel pressure changes (from normal to high).
- If the pressure changes, check the following.
- ECM terminal voltage.
- Engine coolant temperature signal
- Intake air temperature signal
- Throttle valve TVO signal
- If the pressure does not change, do as follows.
- Stop the engine.
- Turn the ignition switch to ON.
- Select the "SIMULATION TEST" function on the NGS display.
- Turn the PRC solenoid valve No.1 from OFF to ON by using the "PRC V" and check if the operation sound of the valve is heard.
- If the operation sound is heard, check the following.
- Pressure regulator.
- Loose or damaged vacuum hose
- If the operation sound is not heard, check the following.
- PRC solenoid valve No.1

Inspection 2
1. Stop the engine.
2. Connect the SSTs to the data link connector 2 located under the driver side dashboard.
3. Verify that diagnostic trouble code No. P1250, P1252 is not displayed.
- If code No. P1250, P1252 is shown, carry out troubleshooting of the code No. P1250, P1252.
4. Start the engine and let it idle.
5. Select the "PID/DATA MONITOR AND RECORD" function on the NGS display after 3 minutes from the engine start.
6. By using the "PRC V2", verify that the PRC solenoid valve No.2 is OFF.
7. If the PRC solenoid valve No.2 is ON, check the following.
- ECM terminal voltage.
- Engine coolant temperature signal
- Intake air temperature signal
8. Select the "SIMULATION TEST" function on the NGS display.
9. Turn the PRC solenoid valve No.2 from OFF to ON by using the "PRC V2" and check if the operation sound of the valve is heard.
- If the operation sound is heard, check the following.
- Loose or damaged vacuum hose
- Pressure regulator.
- If the operation sound is not heard, check the following.
- PRC solenoid valve No.2.