Rail pressure regulator valve(RPRV) is installed in common rail and controls common rail pressure fast as regulating returning quantity of fuel which is delivered to common rail when fast rise of rail pressure is required like the moment of turning engine ON or when fast relief of pressure is required like at the point of deceleration. The lower rail pressure regulator valve current is, the more fuel is supplied to common rail. Thus it leads rail pressure to be high. On the contrary, the higher rail pressure regulator valve current is, the less fuel is supplied to common rail.
DTC P0089 is set when high temperature is detected on control monitoring circuit of PRV(Common rail) side in ECM. It is retrieved if it is short to battery in control monitoring circuit of PRV in ECM.
Item
Detecting Condition
Possible Cause
DTC Strategy
Voltage monitoring
PRV circuit
PRV
Enable Conditions
IG key ON
Threshold Value
High temperature is detected because it is short to battery in PRV control monitoring circuit in ECM.
Diagnostic Time
280ms
Fail Safe
Fuel cut
YES
Temperature of power supply increases to 120? caused by short to battery that make stop supplying power.
EGR Off
NO
Fuel Limit
Check Lamp
ON
Rail pressure regulator valve resistance
Operating frequancy
3.42 ~ 3.78? (20?)
1000Hz(1KHz)
Fig.1) The sensor signal waveform at acceleration and no load.