The pressure control (PC) valve is used to adjust supply pump discharge amount so as to adjust common rail pressure. The discharge amount from the supply pump to the common rail is determined by PC valve current timing.
• | Battery voltage is more than 10 volts. |
• | The engine is running. |
Abnormally high driving voltage with the PC valve ON, the pump is in normal mode, and the battery voltage is higher than 10 volts when the ignition is ON.
• | The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails. |
• | The ECM limits fuel delivery. |
• | 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. |
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 PC valve display on the scan tool while moving connectors and wiring harnesses related to the PC valve sensor. A change in the PC valve scan tool display will indicate the location of the fault. |
Step | Action | Value | Yes | No |
---|---|---|---|---|
Schematic Reference: Engine Controls Schematics | ||||
1 | Does the DTC set with the engine running? | -- | Go to Step 2 | Go to Diagnostic Aids |
2 |
Does the resistance measure within the specified range? | 0.9-1.3 ohms | Go to Step 3 | Go to Step 7 |
3 |
Does the voltage measure less than the specified value? | 1 V | Go to Step 5 | Go to Step 4 |
4 | Repair the short to battery voltage on the PC valve control circuit to the ECM on the PC valve harness. Did you complete the repair? | -- | Go to Step 10 | -- |
5 |
Does The DTC reset? | -- | Go to Step 8 | Go to Step 6 |
6 |
Does the voltage measure less than the specified value? | 1 V | Go to Step 10 | Go to Step 9 |
7 | Replace the PC valve assembly. Did you complete the replacement? | -- | Go to Step 10 | -- |
8 | Replace the ECM. Did you complete the replacement? | -- | Go to Step 10 | -- |
9 | Repair/replace the PC valve harness. Did you complete the action? | -- | Go to Step 10 | -- |
10 | Clear all DTCs. Does the DTC reset? | -- | Go to Step 1 | Go to Step 11 |
11 | Operate the vehicle. Do any other DTCs set? | -- | System OK |
The suction control valve (SCV) is on the fuel supply pump and controls the suction fuel quantity to the fuel rail. The SCV is fully opened in normal state, and increased drive current results in closing the orifice. The engine control module (ECM) calculates the desired fuel rail pressure and fuel flow rate, and compares the desired fuel rail pressure to the actual rail pressure to determine the SCV position. When the actual fuel rail pressure is higher than the desired value, the SCV is closed to decrease the flow rate. If the ECM detects an excessively high SCV solenoid drive current, this DTC will set.
• | The ignition is ON. |
• | The battery voltage is between 10-16 volts. |
• | The fuel supply pump is normal. |
• | The SCV operating duty is between 20-50 percent. |
• | The deviation of the SCV operating duty is less than 10 percent. |
The SCV solenoid operating current is more than 2700 mA.
• | The ECM illuminates the malfunction indicator lamp (MIL) and reduced engine power indicator lamp, if equipped, when the diagnostic runs and fails. |
• | The ECM records the operating conditions at the time the diagnostic fails. The ECM stores this information in the Failure Records. |
• | The ECM limits accelerator operating range. |
• | The ECM limits fuel injection quantity. |
• | The ECM limits fuel rail pressure. |
• | The ECM closes the exhaust gas recirculation (EGR) valve and stops the EGR control. |
• | The ECM inhibits cruise control. |
• | The MIL resets when the ignition is turned OFF. |
• | A current DTC, Last Test Failed, clears when the diagnostic runs and passes. |
• | Clear the MIL and the DTC with a scan tool. |
Step | Action | Values | Yes | No |
---|---|---|---|---|
Schematic Reference: Engine Controls Schematics | ||||
1 | Did you perform the Diagnostic System Check - Engine Controls? | -- | Go to Step 1 | |
2 |
Does the DTC fail this ignition? | -- | Go to Step 3 | Go to Intermittent Conditions |
3 |
Is the resistance within the specified range? | 1.9-2.3 ohms at 20°C (68°F) | Go to Step 4 | Go to Step 7 |
4 |
Did you find and correct the condition? | -- | Go to Step 9 | Go to Step 5 |
5 |
Did you find and correct the condition? | -- | Go to Step 9 | Go to Step 6 |
6 |
Did you find and correct the condition? | -- | Go to Step 9 | Go to Step 8 |
7 |
Important: The SCV is part of the fuel supply pump. Replace the fuel supply pump. Refer to Fuel Injection Pump Replacement . Did you complete the replacement? | -- | Go to Step 9 | -- |
8 |
Important: The new ECM must be programmed. Replace the ECM. Refer to Engine Control Module Replacement/Restore Fuel Rate Data . Did you complete the replacement? | -- | Go to Step 9 | -- |
9 |
Did the DTC fail this ignition? | -- | Go to Step 2 | Go to Step 10 |
10 | Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed? | -- | System OK |