4396630

Check Rail Pressure Regulator.

(1)

Ignition "OFF".

(2)

Disconnect Rail Pressure Regulator.

(3)

Measure resistance between terminal 1 and 2 of rail preussure regulator connecor(Component side).

Specification : 2.07 ~ 2.53 Ω (20°C)

(4)

Is the measured resistance within specifications ?

YES

▶ Go to " Check regulating pressure " as below.

▶ Substitute with a known-good rail pressure regulator and check for proper operation.

If the problem is corrected, replace rail pressure regulator and then go to "Verification of Vehicle Repair" procedure.

Check regulating pressure.

(1)

Ignition "ON" & Engine "ON".

(2)

Monitor signal waveform or graph function of current data by connecting scantool at terminal 2 of Rail preussure regulator.

(3)

Ignition "OFF" then Igintion "ON" before Main relay OFF.

caution

If Main relay OFF, Monitoring current data is impossible. Because Sensor power is cut and communication between scantool and ECM is off.

This test should be done without any leakage from injector nozzle, return line and high pressure line.

Scopemeter

Scantool

Voltage for rail pressure sensor at idle keep up 1.2V ~ 1.4V.

Then, the voltage will drop to 0.7V at the point of Key off.

Finally Signal waveform shows that voltage is getting slow down.

Pressure detected by Rail pressure sensor keep up 250bar at idle.

Then, Pressure will drop rapidly upto 100bar at the point of key off.

Finally, Graph shows that pressure is getting slow down.

(4)

Does the measured pressure drop rapidly upto 100bar after Key OFF ?

YES

▶ Substitute with a known-good rail pressure regulator and check for proper operation.

If the problem is corrected, replace rail pressure regulator and then go to "Verification of Vehicle Repair" procedure.

▶ Substitute with a known-good ECM and check for proper operation.

If the problem is corrected, replace ECM and then go to "Verification of Vehicle Repair" procedure.