DTC P0091:00

Fuel pressure regulator control circuit low input

DETECTION CONDITION

• When the PCM turns the spill valve control solenoid valve off but the spill valve control solenoid valve control circuit voltage is low for 5 s, the PCM determines that the spill valve control solenoid valve control circuit has a malfunction.

MONITORING CONDITIONS

• The following conditions are met:

• Engine speed: 5,700 rpm or less

• Battery voltage: 10.5 V or more

Diagnostic support note

• This is a continuous monitor (CCM).

• The check engine light illuminates if the PCM detects the above malfunction condition during the first drive cycle.

• FREEZE FRAME DATA/Snapshot data is available.

• DTC is stored in the PCM memory.

FAIL-SAFE FUNCTION

• Stops high pressure fuel pump control

• Limits intake air amount

POSSIBLE CAUSE

• High pressure fuel pump connector or terminals malfunction

• PCM connector or terminals malfunction

• Short to ground in wiring harness between high pressure fuel pump terminal B and PCM terminal 1EF

• Open circuit in wiring harness between the following terminals:

• High pressure fuel pump terminal A—PCM terminal 1EE

• High pressure fuel pump terminal B—PCM terminal 1EF

• Spill valve control solenoid valve (built-into high pressure fuel pump) malfunction

• PCM malfunction

Item (definition)

Unit/Condition

Definition

Condition/Specification (Reference)

FUEL_PRES

KPa , mBar , psi, in H20

Fuel pressure input from fuel pressure sensor

• Displays fuel pressure

V

Fuel pressure sensor voltage

Ignition switched ON (engine off)

• Fuel pressure is approx. 3.6 MPa {37 kgf/cm², 522 psi}: Approx. 1.01 V (ECT is 92 °C {198 °F})

Idle (after warm up)

• Fuel pressure is approx. 3.45 MPa {35.2 kgf/cm², 500 psi}: Approx. 1 V (ECT is 92 °C {198 °F})

Racing (Engine speed is 2,000 rpm)

• Fuel pressure is approx. 3.21 MPa {32.7 kgf/cm², 466 psi}: Approx. 0.96 V (ECT is 86 °C {187 °F})

Racing (Engine speed is 4,000 rpm)

• Fuel pressure is approx. 5.59 MPa {57.0 kgf/cm², 811 psi}: Approx. 1.29 V (ECT is 84 °C {183 °F})

LOAD

%

Ratio of actual amount of intake air to the maximum air charging amount (mass volume) of cylinder

• Idle (after warm up): Approx. 27.05% (ECT is 91 °C {196 °F})

• Racing (engine speed is 2,000 rpm): Approx. 16.86% (ECT is 89 °C {192 °F})

• Racing (engine speed is 4,000 rpm): Approx. 17.64% (ECT is 87 °C {189 °F})

RPM

RPM

Engine speed

• Displays engine speed

STEP

INSPECTION

ACTION

1

NOTE:

• Recording can be facilitated using the screen capture function of the PC.

• Record the FREEZE FRAME DATA/snapshot data on the repair order.

—

Go to the next step.

2

• Verify related Service Bulletins and/or on-line repair information availability.

• Is any related repair information available?

Yes

Perform repair or diagnosis according to the available repair information.

• If the vehicle is not repaired, go to the next step.

No

Go to the next step.

3

• Switch the ignition off.

• Disconnect the high pressure fuel pump connector.

• Inspect for poor connection (such as damaged/pulled-out pins, corrosion).

• Is there any malfunction?

Yes

Repair or replace the connector and/or terminals, then go to Step 8.

No

Go to the next step.

4

• Disconnect the PCM connector.

• Inspect for poor connection (such as damaged/pulled-out pins, corrosion).

• Is there any malfunction?

Yes

Repair or replace the connector and/or terminals, then go to Step 8.

No

Go to the next step.

5

• Verify that the high pressure fuel pump and PCM connectors are disconnected.

• Inspect for continuity between high pressure fuel pump terminal B (wiring harness-side) and body ground.

• Is there continuity?

Yes

Refer to the wiring diagram and verify whether or not there is a common connector between high pressure fuel pump terminal B and PCM terminal 1EF.

If there is a common connector:

• Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for a short to ground.

• Repair or replace the malfunctioning part.

If there is no common connector:

• Repair or replace the wiring harness which has a short to ground.

Go to Step 8.

No

Go to the next step.

6

• Verify that the high pressure fuel pump and PCM connectors are disconnected.

• Inspect for continuity between the following terminals (wiring harness-side):

• High pressure fuel pump terminal A—PCM terminal 1EE

• High pressure fuel pump terminal B—PCM terminal 1EF

• Is there continuity?

Yes

Go to the next step.

No

Refer to the wiring diagram and verify whether or not there is a common connector between the following terminals:

• High pressure fuel pump terminal A—PCM terminal 1EE

• High pressure fuel pump terminal B—PCM terminal 1EF

If there is a common connector:

• Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for an open circuit.

• Repair or replace the malfunctioning part.

If there is no common connector:

• Repair or replace the wiring harness which has an open circuit.

Go to Step 8.

7

• Reconnect all disconnected connectors.

• Inspect the spill valve control solenoid valve.

  (See HIGH PRESSURE FUEL PUMP INSPECTION [SKYACTIV-G 2.0].)

• Is there any malfunction?

Yes

Replace the high pressure fuel pump, then go to the next step.

(See HIGH PRESSURE FUEL PUMP REMOVAL/INSTALLATION [SKYACTIV-G 2.0].)

No

Go to the next step.

8

• Always reconnect all disconnected connectors.

• Clear the DTC from the PCM memory using the M-MDS.

  (See AFTER REPAIR PROCEDURE [PCM (SKYACTIV-G 2.0)].)

• Perform the KOEO or KOER self test.

  (See KOEO/KOER SELF TEST [PCM (SKYACTIV-G 2.0)].)

• Is the same DTC present?

Yes

Repeat the inspection from Step 1.

• If the malfunction recurs, replace the PCM.

  (See PCM REMOVAL/INSTALLATION [SKYACTIV-G 2.0].)

Go to the next step.

No

Go to the next step.

9

• Perform the “AFTER REPAIR PROCEDURE”.

  (See AFTER REPAIR PROCEDURE [PCM (SKYACTIV-G 2.0)].)

• Are any DTCs present?

Yes

Go to the applicable DTC inspection.

(See DTC TABLE [PCM (SKYACTIV-G 2.0)].)

No

DTC troubleshooting completed.