Pinpoint Test F: Fuel Pressure Regulator Tests

1. Start (or attempt to start) the engine.

Did the engine start?

• Yes  : GO to  F2.
• No  : GO to Pinpoint Test G .

1. Using the manufacturer approved diagnostic system, check datalogger signal - Fuel Rail Pressure Low Range Sensor (0x0376).
2. Run the engine at idle speed for 60 seconds.
   NOTE: When the engine speed is raised to 3000 rpm, the fuel pressure signal value should be 3.0 V for approximately 30 seconds and then change to 2.3 V.
3. Raise the engine speed to 3000 rpm and check the datalogger signal.

Was the fuel pressure signal value initially 3.0 V ± 0.2 V and then change to 2.3 V ± 0.2 V?

• Yes  : GO to  F4.
• No  : GO to  F3.

1. Using the manufacturer approved diagnostic system, check the engine control module for DTC P0089-29.

   Is P0089-29 set?

• Yes  : Fuel pump internal failure - Fuel pressure regulator failure.

  Install a new fuel pump.

• No  : GO to Pinpoint Test G .

1. Set the ignition to off.
2. Set the ignition to on.
3. Using the manufacturer approved diagnostic system, check datalogger signal - Fuel Rail Pressure Low Range Sensor (0x0376).
4. Start the engine.
5. Using the manufacturer approved diagnostic system, check datalogger signal - Fuel Rail Pressure Low Range Sensor (0x0376).

Is the fuel pressure signal value 4.1 V ± 0.2 V when the engine is not running and 4.75 V ± 0.2 V when the engine is running?

• Yes  : Fuel pressure sensor failure. Install a new fuel pressure sensor.
• No  : No fault found in the low pressure fuel system. Refer to the relevant service information and check the high pressure fuel system and the engine management system.

REFER to:

Fuel Charging and Controls and Electronic Engine Controls (Diagnosis and Testing).