Hino Motors HINO 155 series Workshop Manual page 517

Engine speed pattern
10 MPa or more
Time
Accelerator pattern
222 MPa
Time
ENGINE (J05E)/TROUBLESHOOTING
h. Hunting remains within 10 MPa or more for more than 5 seconds. 
Replace the SCV.
Remains for 5 seconds or longer.
i. The engine stops during pressure relief.  Replace the SCV.
2–481
Actual common rail pressure
Target common rail pressure
SHTS021270300449
Actual common rail pressure
Target common rail pressure
SHTS021270300450