• Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
• Review Strategy Based Diagnosis for an overview of the diagnostic approach.
• Diagnostic Procedure Instructions provides an overview of each diagnostic category.

The high fuel pressure necessary for direct injection is supplied by the high pressure fuel pump. The high pressure fuel pump is mounted on the rear of the engine and is driven by a four-lobe cam on the camshaft. This high pressure fuel pump also regulates the fuel pressure using an actuator in the form of an internal solenoid-controlled valve. In order to keep the engine running efficiently under all operating conditions, the engine control module (ECM) requests pressure ranging from 2 to 15 MPa (290 to 2,176 PSI), depending on engine speed and load. Output drivers in the ECM provide the high pressure fuel pump control circuit with a 12 V pulse-width modulated (PWM) signal, which regulates fuel pressure by opening and closing the control valve at specific times during pump strokes. This effectively regulates the portion of each pump stroke that is delivered to the fuel rail. The high pressure fuel pump is normally closed and will not deliver an increase in fuel pressure when the control solenoid is NOT powered. In the event of pump control failure, the high pressure system is protected by a relief valve in the pump that prevents the pressure from exceeding 24 MPa (3,481 PSI).

The fuel rail pressure sensor provides the feedback necessary to the ECM to control the high pressure fuel pump and the fuel injectors. The sensor is diagnosed separately from the fuel pressure control system.

The ECM monitors the fuel rail pressure sensor and the high pressure fuel pump solenoid to determine if the commanded and actual pressures are within a predetermined range during engine cranking and at all times while the engine is running. The ECM also monitors the high pressure fuel pump solenoid to make sure it is operating within expected limits.

• DTC P0016, P0017, P0090, P0091, P0092, P00C8, P00C9, P00CA, P0111, P0112, P0113, P0114, P0117, P0118, P0119, P0128, P0192, P0193, P0335, P0336, P0340, P0341, P0365, P0366, P0627, P0628, P0629, or P1682 are not present.
• Battery voltage is greater than 8 V.
• The engine has been running for greater than or equal to 10 s.
• Low side fuel pressure is greater than 300 kPa (44 PSI).
• Barometric (BARO) pressure is greater than or equal to 70 kPa.
• Intake air temperature (IAT) is warmer than or equal to −10°C (14°F).
• Fuel temperature is between −10°C and +132°C (14°F and 270°F).
• Vehicle is not in a low fuel condition
• The DTCs run continuously when the above conditions are met.

• DTC P0016, P0017, P0090, P0091, P0092, P00C8, P00C9, P00CA, P0111, P0112, P0113, P0114, P0117, P0118, P0119, P0128, P0192, P0193, P0335, P0336, P0340, P0341, P0365, P0366, P0627, P0628, P0629, or P1682 are not present.
• Ignition voltage is greater than 8 V.
• Engine coolant temperature is less than 65°C (149°F).
• Low side fuel pressure is greater than 300 kPa (44 PSI).
• Vehicle is not in a low fuel condition
• The diagnostic runs once for each engine start.

• DTC P0016, P0017, P0090, P0091, P0092, P00C9, P00CA, P0111, P0112, P0113, P0114, P0116, P0117, P0118, P0119, P0128, P0192, P0335, P0336, P0340, P0341, P0345, P0346, P0365, P0366, P0390, P0391, P0627, P0628, P0629, P111E, P127C, P128A, P128B, P128F, P1682, P16E4, or P16E5 are not present
• Battery voltage is greater than 11 V.
• Low side fuel pressure is greater than 300 kPa (44 PSI).
• Barometric (BARO) pressure is greater than or equal to 70 kPa.
• Intake air temperature (IAT) is warmer than or equal to −10°C (14°F).
• Fuel temperature is between −10°C and +132°C (14°F and 270°F).
• Catalyst Warm up enabled

• The high pressure fuel pump has exceeded the control limits. This condition exists when the Fuel Rail Pressure Regulator Command is 0° or greater than 92° for 12.5 s.

• If the Fuel Rail Pressure Sensor is less than the target set point before the engine is cranked, the pressure rise diagnostic is used.
• The pressure rise diagnostic will fail if the Fuel Rail Pressure Sensor has not increased to the target set point within 9 s at −16°C (3.2°F) ECT or within 4 s if ECT is greater than 0°C (32°F).

• If the Fuel Rail Pressure Sensor is greater than the target set point before the engine is cranked, the pressure fall diagnostic is used.
• The pressure fall diagnostic will fail if the Fuel Rail Pressure Sensor has dropped below 2 MPa (290 PSI) if the ECT is less than −16°C (3.2°F) or 0.6 MPa (87 PSI) if the ECT is greater than −16°C (3.2°F).

• The Fuel Rail Pressure Sensor is less than the Desired Fuel Rail Pressure by a predetermined value.
• The above condition exists for 10.00 s failures out of 12.50 s samples.

• The Fuel Rail Pressure Sensor is greater than the Desired Fuel Rail Pressure by a predetermined value.
• The above condition exists for 10.00 s failures out of 12.50 s samples.

• This DTC determines when the high pressure pump control has reached to its max or min authority during Cataylst Warm up.
• The above condition exists for 10.00 seconds failures out of 12.50 Seconds samples.

• DTCs P0089 and P00C6 are Type B DTCs.
• DTCs P228C, P228D, P2C1E, P2C1F and P2C20 are Type A DTCs.
• A message center or an indicator displays Reduced Engine Power.
• Scan tool control of the high pressure fuel pump is inhibited.

• DTCs P0089 and P00C6 are Type B DTCs.
• DTCs P228C, P228D, P2C1E, P2C1F and P2C20 are Type A DTCs.

• Any problem with the camshaft may set fuel pressure DTCs due to the location and design of the high pressure fuel pump. If camshaft position control DTCs are current or in history, a cam control issue may be the root cause.
• A faulty valve, plunger, or solenoid in the high pressure fuel pump may set a DTC. High pressure fuel pump damage will most likely be undetectable upon visual inspection.
• A restricted fuel feed pipe between the fuel feed pipe fuel pressure sensor and the high pressure fuel pump may set a DTC.
• A leaking or restricted fuel injector may set a DTC.
• A leak in the high pressure fuel system may set a DTC.
• Vapor lock may set DTC P0089
• For DTC P00C6, P2C1E, P2C1F, and P2C20, park the vehicle outdoors overnight and perform a start in the morning.

Engine Controls Schematics

Master Electrical Component List

Fuel System Description

• Circuit Testing
• Connector Repairs
• Testing for Intermittent Conditions and Poor Connections
• Wiring Repairs

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Control Module References for scan tool information

1. Ignition » On / Vehicle » In Service Mode
2. Verify DTC  P0016, P0017, P0018, P0019, P0090, P0091, P0092, P00C8, P00C9, P00CA, P0111, P0112, P0113, P0116, P0117, P0118, P0128, P0192, P0193, P0335, P0336, P0340, P0341, P0345, P0346, P0365, P0366, P0390, P0391, P0628, P163A is not set
• If any of the DTCs are set

  Refer to:Diagnostic Trouble Code (DTC) List - Vehicle

• If none of the DTCs are set
3. Engine»Idling
4. Verify the scan tool parameter:Fuel Rail Pressure Sensor=1.9 to 5.0 MPa (276 to 725 PSI)
• If not between 1.9 and 5.0 MPa (276 and 725 PSI)

  Refer to: Circuit/System Testing

• If between 1.9 and 5.0 MPa (276 and 725 PSI)
5. Perform the following action:Clear the DTCs.

Warning: Road test a vehicle under safe conditions and while obeying all traffic laws. Do not attempt any maneuvers that could jeopardize vehicle control. Failure to adhere to these precautions could lead to serious personal injury and vehicle damage.

6. Accelerate the vehicle with wide open throttle.

Verify DTC P0089, P00C6, P228C, P228D, P2C1E, P2C1F, P2C20 is not set

• If DTC P0089, P00C6, P228C, P228D, P2C1E, P2C1F, P2C20 is set

  Refer to: Circuit/System Testing

• If DTC P0089, P00C6, P228C, P228D, P2C1E, P2C1F, P2C20 is not set
7. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

   Verify the DTC does not set.

• If the DTC sets

  Refer to: Circuit/System Testing

• If the DTC is not set
8. All OK.

Note: Circuit/System Verification must be performed first or misdiagnosis may result.

1. Remove the G18 High Pressure Fuel Pump.
2. Verify the lobes on the camshaft do not have unusual wear or are worn.
• If the lobes have unusual wear or are worn

  Replace the Camshaft.

• If the lobes are OK
3. Test or replace the G18 High Pressure Fuel Pump.

1. Ignition OFF, disconnect the harness connector at the G18 High Pressure Fuel Pump.

Note: The DMM and test leads must be calibrated to 0 Ω in order to prevent misdiagnosis.

2. Test for 1.09–1.21 Ω at 20°C (68°F) between the high control circuit terminal 2 and the low control circuit terminal 1.
• If not between 1.09–1.21 Ω

  Replace the G18 High Pressure Fuel Pump.

• If between 1.09–1.21 Ω
3. Test for infinite resistance between each terminal and the G18 High Pressure Fuel Pump housing.
• If less than infinite resistance

  Replace the G18 High Pressure Fuel Pump.

• If infinite resistance
4. All OK

Perform the Diagnostic Repair Verification after completing the repair.

• Fuel Pump Replacement for the G18 High Pressure Fuel Pump replacement.
• Intake and Exhaust Camshaft, Bearing Cap, and Lash Adjuster Removal
• Perform the Fuel Rail Pressure Relief Valve Reset procedure, if supported on the scan tool.