Code No. P0193: Rail Pressure Sensor Circuit High Input
OPERATION
- A power voltage of 5 V is applied to the rail pressure sensor power terminal from the engine-ECU connector terminal FPS5 and earthed to the engine-ECU connector terminal FPSE from the rail pressure sensor connector terminal.
- The sensor signal is inputted to the engine-ECU connector terminal FPS from the rail pressure sensor output terminal.
FUNCTION
- The rail pressure sensor converts the rail pressure into a voltage signal and inputs the signal to the engine-ECU.
- In response to the signal, the engine-ECU corrects the fuel injection quantity.
TROUBLE JUDGEMENT
Check Conditions
- Battery positive voltage is 8 - 16 V
- 2 seconds later after the ignition switch has been in "ON" position or the engine has started up.
Judgement Criterion
- The rail pressure sensor output voltage is 4.85 V or more.
FAIL-SAFE AND BACKUP FUNCTION
- The rail pressure is controlled in the range between 50 and 100 MPa.
- The fuel injection amount is restricted (output restriction).
- The open angle of the accelerator pedal is restricted.
- The throttle valve is closed (fixed opening degree).
- The EGR control is stopped (fully closed).
- The DPF regeneration is prohibited.
PROBABLE CAUSES
- Failed rail pressure sensor
- Open circuit or harness damage in rail pressure sensor circuit or loose connector contact
- Failed engine-ECU
|
|
STEP 1. M.U.T.-III data list
|
|
|
- Refer to Data List Reference Table
 .
- Item 63: Rail pressure sensor
|
|
|
Q.
Is the check result normal?
|
|
|
 Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions).
|
|
|
|
|
|
 Go to Step 2.
|
|
|
|
|
|
STEP 2. Voltage measurement at rail pressure sensor connector (FPS5 line).
|
|
|
(1)Disconnect the connector, and measure at the wiring harness side.
|
|
|
(3)Check the voltage between the rail pressure sensor connector (FPS5 line) and body earth.
OK: 4.9 - 5.1 V
|
|
|
Q.
Is the check result normal?
|
|
|
Go to Step 5.
|
|
|
|
|
|
Go to Step 3.
|
|
|
|
|
|
STEP 3. Check of open circuit and short to earth in FPS5 line between rail pressure sensor connector and engine-ECU connector.
|
|
|
Q.
Is the check result normal?
|
|
|
Go to Step 4.
|
|
|
|
|
|
Repair the connector(s) or wiring harness.
|
|
|
|
|
|
STEP 4. M.U.T.-III data list
|
|
|
- Refer to Data List Reference Table .
- Item 63: Rail pressure sensor
|
|
|
Q.
Is the check result normal?
|
|
|
Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions).
|
|
|
|
|
|
Replace the engine-ECU.
|
|
|
|
|
|
STEP 5. Resistance measurement at rail pressure sensor connector (FPSE line).
|
|
|
(1)Disconnect the connector, and measure at the wiring harness side.
|
|
|
(2)Measure the resistance between the rail pressure sensor connector (FPSE line) and body earth.
OK: Continuity (2 Ω or less)
|
|
|
Q.
Is the check result normal?
|
|
|
Go to Step 7.
|
|
|
|
|
|
Go to Step 6.
|
|
|
|
|
|
STEP 6. Check of open circuit and damage in FPSE line between engine-ECU connector and rail pressure sensor connector.
|
|
|
Q.
Is the check result normal?
|
|
|
Go to Step 10.
|
|
|
|
|
|
Repair the connector(s) or wiring harness.
|
|
|
|
|
|
STEP 7. Check of damage in FPS5 line between rail pressure sensor connector and engine-ECU connector.
|
|
|
Q.
Is the check result normal?
|
|
|
Go to Step 8.
|
|
|
|
|
|
Repair the connector(s) or wiring harness.
|
|
|
|
|
|
STEP 8. Check of damage in FPS line between rail pressure sensor connector and engine-ECU connector.
|
|
|
Q.
Is the check result normal?
|
|
|
Go to Step 9.
|
|
|
|
|
|
Repair the connector(s) or wiring harness.
|
|
|
|
|
|
STEP 9. Voltage measurement at rail pressure sensor connector (FPS line).
|
|
|
(1)Disconnect connector, and measure at sensor side.
|
|
|
(2)With the special tool test harness (MB991658) bridge only the mating terminals of FPS5 line and FPSE line of the disconnected connector.
|
|
|
(4)Check the voltage between the rail pressure sensor connector (FPS line) and body earth.
OK: 0.85 V or more
|
|
|
Q.
Is the check result normal?
|
|
|
Go to Step 10.
|
|
|
|
|
|
Replace the rail pressure sensor.
|
|
|
|
|
|
STEP 10. M.U.T.-III data list
|
|
|
- Refer to Data List Reference Table .
- Item 63: Rail pressure sensor
|
|
|
Q.
Is the check result normal?
|
|
|
Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions).
|
|
|
|
|
|
Replace the engine-ECU.
|
|
|
|