Check the waveform and the voltage of the accelerator pedal position sensor 1 and the rail pressure sensor using the GDS.
Items | Specification | |
High Pressure Fuel Pressure Range | bar | 0 ~ 2200 |
MPa | 0 ~ 220 | |
kgf/cm² | 0 ~ 2243.4 | |
psi | 0 ~ 31908.3 | |
Figure 1) The waveform of accelerator pedal position sensor 1 and the rail pressure sensor.
Connect the GDS to Data Link Connector (DLC).
Idle the engine until the temperature reaches normal operating condition.
Turn off all electrical systems (headlamps, A/C, etc.).
Check the actual rail pressure and the target rail pressure.
Specification : Almost the same
Figure 1) Check the "Rail pressure" at idle after warming up the engine.
Inspect other fuel systems to see if the rail pressure is different from the target rail pressure.
Possible cause : Wear, Leakage etc.
Inspect other fuel systems to see if the rail pressure control valve is not within the specification.
Possible cause : Wear, Leakage etc.
Connect the GDS to Data Link Connector (DLC).
Idle the engine until the temperature reaches normal operating condition.
Turn off all electrical systems (headlamps, A/C, etc.).
Inspect the following items.
Items | Specification | |
High Pressure Fuel Pressure Range | bar | 0 ~ 2200 |
MPa | 0 ~ 220 | |
kgf/cm² | 0 ~ 2243.4 | |
psi | 0 ~ 31908.3 | |
Item | Duty (Current) | Valve | Rail Pressure |
Fuel pressure control valve (Normal open type) [High pressure pump] | Increase | Close | Decrease |
Decrease | Open | Increase | |
Rail pressure control valve (Normal open type) [Common rail] | Decrease | Open | Decrease |
Increase | Close | Increase |
Figure 1 represents the duty cycle of "Rail pressure", "Target rail pressure", "Fuel pressure controler (rail)", and "Fuel pressure controler (pump)" during acceleration and deceleration.
FPCV in the high pressure fuel pump shows about 30% duty at idle status, and increases to about 40% to raise the rail pressure at acceleration.→ If the duty of the FPCV in the pump decreases, the fuel amount that goes to common rail from injection pump increases. The rail pressure control valve shows about 19% duty cycle and increases to about 45% to raise the rail pressure at acceleration. The increase of duty means the increase of current. → If the current increases, the fuel return amount decreases and the pressure of common rail increases.
