DTC P1088: Rail Pressure (RP) Low
- Check the ''On Board Diagnostic (OBD) System Check''.
Was the ''OBD System Check'' performed?
YES – Go to step 2.
NO – Go to OBD System Check. 
- Check the DTC.
Are there any other DTC (beside DTC P1088) being output?
YES – Go to relevant DTC chart.
NO – Go to step 3.
- Disconnect ECM connector.
- Measure resistance of RP sensor as below.
- Between terminal 86 and 90.
Is there 0.9 – 1.3 ohms? (At indoor temperature)
YES – Go to step 5.
NO – Go to step 8.
- Turn the engine ON at idling.
- Check the RP sensor signal voltage.
Is about 1 V indicated?
YES – Intermittent failure, system is OK at this time. Check for poor connections or loose wires at the RP sensor and at the ECM.
NO – Go to step 7.
- Check for the following conditions:
- Damaged supply pump.
- Damaged common rail.
- Damaged fuel metering unit.
- Fuel leaks injection pipes.
- Damaged the RP sensor.
Is a problem found?
YES – Repair as necessary.
NO – Go to step 8.
- Turn the ignition switch OFF.
- Disconnect the RP sensor 3P connector terminals No. 1 and No. 2 with a jumper wire.
Wire side of female terminals
RP sensor 3P connector
JUMPER WIRE