Circuit Description
The common rail is located on the intake manifold. The common rail is equipped with a flow damper, a pressure limiter, and a common rail pressure sensor.
The common rail unit has a common fuel passage, fuel passage holes, and installing threaded holes. The common fuel passage is a through hole made in the common rail unit. The common rail pressure (PC) sensor is installed at the left end of the unit.
The engine control monitor (ECM) monitors the common rail pressure signals for voltage outside the normal range of the common rail pressure sensor. If the ECM detects a common rail pressure signal voltage that is excessively abnormal, DTC 0115 will set.
Conditions for Setting the DTC
| • | The engine is running. |
| • | DTC 0245 is not set. |
| • | PC sensor indicates a variation of more than 10 mPa (1,450 psi). |
Action Taken When the DTC Sets
| • | The ECM will illuminate the malfunction indicator lamp (MIL) the first time the fault is detected. |
| • | Limits are set to common rail pressure Open Loop control, common rail pressure, and fuel injection amount. |
| • | Common rail pressure: 60 mPa (8,702 psi) maximum fuel injection amount is limited for 50 mm³/seconds. |
Conditions for Clearing the MIL/DTC
| • | The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail. |
| • | A current DTC, Last Test Failed, clears when the diagnostic runs and passes. |
| • | A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic. |
| • | Clear the MIL and the DTC with a scan tool. |
DTC 0115 can be cleared by using the Clear Info on the scan tool or by using the Diag Clear Switch.
Diagnostic Aids
Inspect for the following conditions:
| • | Poor connection at the ECM |
| Inspect the harness connectors for backed-out terminals, improper mating, broken locks, improperly formed or damaged terminals, and poor terminal-to-wire connection. |
| • | Damaged harness |
| Inspect the wiring harness for damage, shorts to ground, shorts to battery, and open circuits. If the harness appears to be OK, observe the common rail pressure display on the scan tool while moving connectors and wiring harnesses related to the Rail pressure sensor. A change in the common rail pressure scan tool display will indicate the location of the fault. |
Step | Action | Value | Yes | No | ||||||
|---|---|---|---|---|---|---|---|---|---|---|
Schematic Reference: Engine Controls Schematics | ||||||||||
1 | Does DTC 0115 set while the engine is running or when the ignition is ON? | -- | Go to Step 2 | Go to Diagnostic Aids | ||||||
2 |
The fuel pressure 25 MPa (3,626 psi) and the voltage about 1.4 volts at idling Does the voltage measure within the specified range? | 0.9-1.1 V | Go to Step 3 | Go to Step 4 | ||||||
3 |
Does the voltage measure near the specified value? | 1.4 V | Go to Step 5 | Go to Step 4 | ||||||
4 |
Does each resistance measure less than the specified value? | 2 ohms | Go to Step 10 | Go to Step 12 | ||||||
5 |
Measure voltage while the engine is idling and varying the engine RPM using the accelerator pedal. Does voltage vary? | -- | Go to Step 14 | Go to Step 6 | ||||||
6 |
Does each resistance measure less than the specified value? | 2 ohms | Go to Step 7 | Go to Step 14 | ||||||
7 | Measure the resistance between pin number 71 and 62 at the ECM connector C2 and a good ground. Does the resistance measure more than the specified value? | 10 M ohms | Go to Step 8 | Go to Step 12 | ||||||
8 |
Does DTC 0115 reset? | -- | Go to Step 9 | Go to Step 13 | ||||||
9 | Start the engine and accelerate a few times. Does DTC 0115 reset? | -- | Go to Step 11 | System OK | ||||||
10 | Replace the PC sensor. Did you complete the replacement? | -- | Go to Step 14 | -- | ||||||
11 | Replace the ECM. Refer to Engine Control Module Replacement/Restore Fuel Rate Data . Did you complete the replacement? | -- | Go to Step 14 | -- | ||||||
12 | Repair/replace the PC sensor wiring harness. Did you complete the action? | -- | Go to Step 14 | -- | ||||||
13 | Repair the poor connection at the harness connector. Did you complete the repair? | -- | Go to Step 14 | -- | ||||||
14 | Clear the DTCs Does DTC 0115 reset? | -- | Go to Step 2 | System OK | ||||||
