Test Description

The numbers below refer to the step numbers in the diagnostic procedures.

1. 2  - This step verifies that the HPL solenoid and the FTP sensor are functioning. A fuel tank pressure value that decreases while the engine is operating indicates the HPL is not opening or the manual tank valve is closed.
2. 3  - This step verifies the FRP sensor is displaying the correct fuel pressure.
3. 4  - This step tests for a leak in the fuel system between the LPL, and the fuel injectors. The fuel pressure should remain constant during the test.

   5  - This step tests the HPR output pressure. If the fuel pressure is within the specified values, then the HPR, fuel lines, and filters are okay.

4. 6  - This step tests the operation of the HPL.
5. 8  - This step tests the HPR output pressure. If the fuel pressure is within the specified values, then the HPR, fuel lines, and filters are okay.
6. 14  - This step verifies that a fuel filter is not the cause of the condition. If the fuel pressure is within the specified range after the fuel filter replacement, then a plugged filter was the cause of the condition.