Service Information

Orlando

DTC P228C or P228D — LNP or LNQ

Diagnostic Instructions

•	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.

DTC Descriptors

DTC P228C 00: Fuel Pressure Regulator 1 Control Performance - Low Pressure

DTC P228D 00: Fuel Pressure Regulator 1 Control Performance - High Pressure

Diagnostic Fault Information

Circuit	Short to Ground	Open/High Resistance	Short to Voltage	Signal Performance
Ignition	P0091 00	P0091 00	-	-
Output Control	P0091 00	P0090 00	P0092 00	-

The fuel pressure regulator solenoid is used to control the fuel pressure from the high pressure fuel pump to the fuel rail. The fuel pressure regulator solenoid is pulse width modulated (PWM). An ignition voltage is supplied to the fuel pressure regulator solenoid. The ECM controls the solenoid by grounding the control circuit with a solid state device called a driver.

Conditions for Running the DTC

•	The ignition is ON or the engine is running.

•	The ignition voltage is less than 16 V.

•	The DTC runs continuously once the above conditions are met.

Conditions for Setting the DTC

P228C 00

The actual fuel rail pressure is more than 11 MPa (1 595 PSI) below the desired fuel rail pressure for more than 8 s.

P228D 00

The actual fuel rail pressure is more than 20 MPa (2 900 PSI) above the desired fuel rail pressure for more than 8 s.

Action Taken When the DTC Sets

DTCs P228C 00, and P228D 00 are Type C DTCs.

Conditions for Clearing the DTC

DTCs P228C 00, and P228D 00 are Type C DTCs.

Diagnostic Aids

P228C

Note: If the Change Fuel Filter Warning light is ON with DTC P228C, inspect the fuel filter for a restriction or contamination.

•

A restricted fuel supply line, a leakage in the high pressure section, too much or too little fuel in the low pressure line may cause DTCs to set. When ambient temperatures are below 0°C (32°F), the fuel tank pickup screen may be iced over from water in the fuel tank. A restricted, kinked, or damaged fuel supply line may cause DTC P0087 to set.

•	High resistance in either circuit of the fuel pressure regulator will cause a DTC to set.

•	There are no driveability concerns associated with the fuel rail pressure regulator unless a DTC is present. One of the causes of these DTCs is a sticking fuel rail pressure regulator.

•	If the fuel system pressure is actually too high, a fuel knock and smoke condition will exist.

Reference Information

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Component Connector End Views

Electrical Information Reference

•	Circuit Testing

•	Connector Repairs

•	Testing for Intermittent Conditions and Poor Connections

•	Wiring Repairs

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

Special Tools

EN 34730-1A Fuel Pressure Gauge

For equivalent regional tools, refer to Special Tools .

Circuit/System Verification

Ignition ON, observe the DTC information with a scan tool. Verify that no other DTCs are set.

⇒	If any other DTCs are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle for further diagnosis.

Engine running, observe the scan tool DTC information parameter. DTCs P228C 00, or P228D 00 should not set.
Operate the vehicle within the conditions for running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the freeze frame/failure records data.

Circuit/System Testing

Ignition OFF, disconnect the harness connector at the Q18 Fuel Pressure Regulator.
Ignition ON, verify a test lamp illuminates between the ignition voltage circuit terminal 2 and ground.

⇒	If the test lamp does not illuminate, repair the ignition voltage circuit for a short to ground or an open/high resistance.

Ignition ON, test for 6.5-11 V between the control circuit terminal 1 and ground.

⇒	If less than the specified range, test the control circuit for an open or a short to ground. If the circuit tests normal, replace the K20 Engine Control Module.

⇒	If greater than the specified range, test the control circuit for a short to voltage. If the circuit tests normal, replace the K20 Engine Control Module.

Ignition OFF, test for less than 5 Ω between the control circuit terminal 2 and the K20 Engine Control Module.

⇒	If greater than the specified range, repair the control circuit for a high resistance.

If all circuits test normal, test or replace the Q18 Fuel Pressure Regulator.
Inspect and repair one of the following conditions:

Low Pressure

•	A fuel system leak

•	Restricted fuel filter

•	Injection nozzle stuck in open position

•	Leakage in the fuel rail pressure regulator

•	Worn fuel injection pump

High Pressure

•	Restricted fuel return

•	Fuel injection pump stuck open

•	Fuel rail pressure regulator stuck closed

•	Restricted fuel injector

If all circuits test normal, replace the Q18 Fuel Pressure Regulator.

Component Testing

Static Test

Ignition OFF, disconnect the harness connector at the Q18 Fuel Pressure Regulator.
Test for 6-7 Ω between the control terminal 1 and the ignition voltage terminal 2.

⇒	If not within the specified range, replace the Q18 Fuel Pressure Regulator.

Test for infinite resistance between each terminal and the Q18 Fuel Pressure Regulator housing.

⇒	If not the specified value, replace the Q18 Fuel Pressure Regulator.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

•	Fuel Injection Pump Replacement

•	Fuel Injector Replacement

•	Control Module References for ECM replacement, programming and setup