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2014 - Mazda6 - Engine

DTC P0171:00 [SKYACTIV-G 2.5]

NOTE:

Details On DTCs



DESCRIPTION

Fuel trim system too lean

DETECTION CONDITION

Determination conditions

  • Any one of the following conditions is met:

    • While the engine is idling or the vehicle is driven, the fuel feedback correction amount (30 %) is the threshold or more, and the fuel learning correction amount is the specified value (15 %) or more for 10 s or more.

    • While the engine is idling or the vehicle is driven, the fuel feedback correction amount reaches the upper limit (25 % or more) for 20 s or more.

Preconditions

  • Engine coolant temperature: 0—45 °C {32—113 °F}, 60 °C {140 °F} or more*1

  • *1: Value can be verified by displaying PIDs using M-MDS

Malfunction determination period

  • 10 s or 20 s period

Drive cycle

  • 2

Self test type

  • CMDTC self test

Sensor used

  • A/F sensor

FAIL-SAFE FUNCTION

  • Not applicable

VEHICLE STATUS WHEN DTCs ARE OUTPUT

  • Illuminates check engine light.

  • Rough idling, poor acceleration, stalling

POSSIBLE CAUSE

  • Erratic signal to PCM

    • ECT sensor No.1 signal malfunction

    • MAF sensor signal malfunction

    • MAP sensor signal malfunction

    • IAT sensor No.2 signal malfunction

    • Related connector or terminals malfunction

    • Related wiring harness malfunction

  • Fuel runout

  • High-pressure side fuel delivery system malfunction

    • Fuel pressure sensor malfunction

    • Relief valve (built-into high pressure fuel pump) malfunction

    • Spill valve control solenoid valve control circuit malfunction (damage to driver in PCM caused by short circuit to ground system)

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

    • High pressure fuel pump malfunction

  • Fuel leakage in fuel line

  • Low-pressure side fuel delivery system malfunction

    • Fuel filter clogged (built-into fuel pump unit)

    • Low pressure side fuel line restriction (between fuel pump unit and high pressure fuel pump)

    • Fuel pump unit malfunction

    • Pressure regulator (built-into fuel pump unit) malfunction

    • Fuel pump control module malfunction

  • Fuel injector malfunction

    • Improper operation of fuel injector

    • Fuel injector related wiring harness malfunction

  • Improper operation of purge control system

    • Purge solenoid valve malfunction

    • Purge solenoid hoses improper connection

  • PCV valve malfunction

  • MAF sensor malfunction

  • Air cleaner element malfunction

  • MAP sensor malfunction

  • Air suction in intake air system

  • Improper operation of electric variable valve timing control system

    • Electric variable valve timing driver malfunction

    • Electric variable valve timing motor malfunction

    • Electric variable valve timing actuator malfunction

  • Improper operation of hydraulic variable valve timing control system

  • A/F sensor malfunction

    • A/F sensor loose

    • Exhaust system leakage

  • Poor fuel quality

  • PCM malfunction


System Wiring Diagram

Function Explanation (DTC Detection Outline)

Repeatability Verification Procedure

PID Item/Simulation Item Used In Diagnosis

PID/DATA monitor item table

Item

Definition

Unit

Condition/Specification

APP

Accelerator pedal position

%

  • Accelerator pedal released: Approx. 0%

  • Accelerator pedal depressed: Approx. 100%

ECT

Engine coolant temperature

°C, °F

  • Displays ECT

V

  • ECT is 20 °C {68 °F}: Approx. 3.10 V

  • ECT is 40 °C {104 °F}: Approx. 2.16 V

  • ECT is 60 °C {140 °F}: Approx. 1.40 V

  • ECT is 80 °C {176 °F}: Approx. 0.87 V

  • ECT is 100 °C {212 °F}: Approx. 0.54 V

EVAPCP

Purge solenoid valve control signal

%

  • Idle (after warm up): Approx. 0%

  • Racing (Engine speed 2,000 rpm): 4.3—35%

  • Racing (Engine speed 4,000 rpm): Approx. 66%

FP

Fuel pump relay condition

Off/On

  • Switch ignition ON (engine off): Off

  • Cranking: On

  • Idle (after warm up): On

FUEL_PRES

Fuel pressure sensor input signal

KPa {MPa}, mBar {Bar}, psi, in H20

  • Displays fuel pressure

V

  • Fuel pressure is 3.0 MPa {31 kgf/cm2, 435 psi}: Approx. 0.92 V

  • Fuel pressure is 4.8 MPa {49 kgf/cm2, 696 psi}: Approx. 1.17 V

HTR11

A/F sensor heater operation signal

Off/On

  • Switch ignition ON (engine off): Off

  • Idle (after warm up): On

%

  • Switch ignition ON (engine off): 0%

  • Idle (after warm up): Approx. 40%

MAF

Mass airflow

g/Sec

  • Displays MAF

V

  • Switch ignition ON (engine off) (MAF: 0.59 g/s {0.078 lb/min}): Approx. 0.72 V

  • Idle (after warm up) (MAF: 2.17 g/s {0.287 lb/min}): Approx. 0.86 V

  • Racing (engine speed is 2,000 rpm) (MAF: 4.73 g/s {0.626 lb/min}): Approx. 1.07 V

MAP

Manifold absolute pressure

KPa {MPa}, mBar {Bar}, psi, in H20

  • Displays MAP

V

  • Switch ignition ON (engine off) (MAP:101 kPa {1.03 kgf/cm2, 14.6 psi}): Approx. 4.07 V

  • Idle (after warm up) (MAP: 33 kPa {0.34 kgf/cm2, 4.8 psi}): Approx. 1.34 V

  • Racing (engine speed is 2,000 rpm) (MAP: 26 kPa {0.27 kgf/cm2, 3.8 psi}): Approx. 1.05 V

O2S11

A/F sensor input signal

µA

  • Idle (after warm up): Approx. -39 µA

  • Deceleration fuel cut (accelerator pedal released from engine speed of 4,000 rpm or more): Approx. 3.84 mA

TP REL

Throttle position

%

  • Accelerator pedal released: Approx. 12%

  • Accelerator pedal depressed: Approx. 82%

VT_EX_ACT

Actual exhaust valve timing

°

  • Displays actual exhaust valve timing

VT EX_DES

Desired exhaust valve timing

°

  • Displays desired exhaust valve timing

VT IN_ACT

Actual intake valve timing

°

  • Displays actual intake valve timing

VT IN_DES

Desired intake valve timing

°

  • Displays desired intake valve timing


Simulation item table

Item

Definition

Unit

Operation

INJ_1

Fuel injector No.1

OFF

  • Select OFF to forcibly stop fuel injector No.1.

INJ_2

Fuel injector No.2

OFF

  • Select OFF to forcibly stop fuel injector No.2.

INJ_3

Fuel injector No.3

OFF

  • Select OFF to forcibly stop fuel injector No.3.

INJ_4

Fuel injector No.4

OFF

  • Select OFF to forcibly stop fuel injector No.4.


Function Inspection Using M-MDS



STEP

INSPECTION

RESULTS

ACTION

1

PURPOSE: VERIFY RELATED REPAIR INFORMATION AVAILABILITY
  • 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.

2

PURPOSE: IDENTIFY TRIGGER DTC FOR FREEZE FRAME DATA (MODE 2)
  • Is the DTC P0171:00 on FREEZE FRAME DATA (Mode 2)?

Yes

Go to the next step.

No

Go to the troubleshooting procedure for DTC on FREEZE FRAME DATA (Mode 2).

(See DTC TABLE [SKYACTIV-G 2.5].)

3

PURPOSE: RECORD VEHICLE STATUS AT TIME OF DTC DETECTION TO UTILIZE WITH REPEATABILITY VERIFICATION
  • Has the FREEZE FRAME DATA (Mode 2)/snapshot data been recorded?

Yes

Go to the next step.

No

Record the FREEZE FRAME DATA (Mode 2)/snapshot data on the repair order, then go to the next step.

NOTE:

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

4

PURPOSE: VERIFY IF INPUT SIGNAL TO PCM AFFECTS FUEL INJECTION

Yes

Inspect the suspected sensor and related wiring harness.

  • If there is any malfunction:

    • Repair or replace the malfunctioning part.

    • Go to the troubleshooting procedure to perform the procedure from Step 24.

  • If there is no malfunction:

    • Go to the next step.

No

Go to the next step.

5

PURPOSE: VERIFY CONNECTOR CONNECTIONS
  • Start the engine.

  • Access the following PIDs using the M-MDS:

    (See ON-BOARD DIAGNOSTIC TEST [SKYACTIV-G 2.5].)

    • FUEL_PRES

    • FP

    • EVAPCP

    • MAF

    • MAP

    • VT_EX_ACT

    • VT IN_ACT

  • When the following parts are shaken, does the PID value include a PID item which has changed?

    • Fuel pressure sensor

    • Fuel pump control module

    • Purge solenoid valve

    • MAF sensor

    • MAP sensor

    • OCV

    • Electric variable valve timing motor/driver

    • PCM

Yes

Repair or replace the applicable connector parts.

Go to the troubleshooting procedure to perform the procedure from Step 24.

No

Go to the next step.

6

PURPOSE: VERIFY FUEL PRESSURE (HIGH-SIDE) MALFUNCTION
  • Switch the ignition off.

  • Reconnect all disconnected connectors.

  • Start the engine and idle it.

  • Access the FUEL_PRES PID using the M-MDS.

    (See ON-BOARD DIAGNOSTIC TEST [SKYACTIV-G 2.5].)

  • Is the FUEL_PRES PID value approx. 3 MPa {31 kgf/cm2, 435 psi}?

Yes

Go to the next step.

No

FUEL_PRES PID value is lower than 3 MPa {31 kgf/cm2, 435 psi}:

  • Go to the troubleshooting procedure to perform the procedure from Step 1.

FUEL_PRES PID value is higher than 3 MPa {31 kgf/cm2, 435 psi}:

  • Go to Step 8.

7

PURPOSE: VERIFY FUEL PRESSURE (LOW-SIDE) MALFUNCTION
  • Switch the ignition off.

  • Disconnect the high pressure fuel pump connector.

  • Start the engine and idle it.

  • Access the FUEL_PRES PID using the M-MDS.

    (See ON-BOARD DIAGNOSTIC TEST [SKYACTIV-G 2.5].)

  • Is the FUEL_PRES PID value approx. 200 kPa {2.04 kgf/cm2, 29.0 psi} or more?

Yes

Go to the next step.

No

Go to the troubleshooting procedure to perform the procedure from Step 5.

8

PURPOSE: VERIFY IF MALFUNCTION CAUSED BY FUEL INJECTOR IMPROPER OPERATION
  • Switch the ignition off.

  • Reconnect all disconnected connectors.

  • Start the engine and idle it.

  • Access the following simulation items using the M-MDS:

    (See ON-BOARD DIAGNOSTIC TEST [SKYACTIV-G 2.5].)

    • INJ_1

    • INJ_2

    • INJ_3

    • INJ_4

  • Turn each fuel injector from on to off using the simulation items.

  • Does the vibration during idling worsen?

Yes

Go to the next step.

No

Go to the troubleshooting procedure to perform the procedure from Step 7.

9

PURPOSE: VERIFY IF MALFUNCTION CAUSED BY PURGE SOLENOID VALVE IMPROPER OPERATION

Yes

Go to the next step.

No

Go to the troubleshooting procedure to perform the procedure from Step 8.

10

PURPOSE: VERIFY MAF SENSOR

Yes

Go to the next step.

No

Go to the troubleshooting procedure to perform the procedure from Step 10.

11

PURPOSE: VERIFY MAP SENSOR

Yes

Go to the next step.

No

Go to the troubleshooting procedure to perform the procedure from Step 12.

12

PURPOSE: VERIFY INTAKE VALVE TIMING
  • Start the engine and idle it.

  • Access the following PIDs using the M-MDS:

    (See ON-BOARD DIAGNOSTIC TEST [SKYACTIV-G 2.5].)

    • VT IN_ACT

    • VT IN_DES

  • Depress the accelerator pedal to increase the engine speed.

  • Does the monitor value of the PID item VT IN_ACT conform to the VT IN_DES PID value?

Yes

Go to the next step.

No

Go to the troubleshooting procedure to perform the procedure from Step 14.

13

PURPOSE: VERIFY EXHAUST VALVE TIMING
  • Start the engine and idle it.

  • Access the following PIDs using the M-MDS:

    (See ON-BOARD DIAGNOSTIC TEST [SKYACTIV-G 2.5].)

    • VT_EX_ACT

    • VT EX_DES

  • Depress the accelerator pedal to increase the engine speed.

  • Does the monitor value of the PID item VT_EX_ACT conform to the VT EX_DES PID value?

Yes

Go to the next step.

No

Go to the troubleshooting procedure to perform the procedure from Step 17.

14

PURPOSE: VERIFY A/F SENSOR

Yes

Go to the next step.

No

Go to the troubleshooting procedure to perform the procedure from Step 18.

15

PURPOSE: VERIFY DTC

Yes

Go to the applicable DTC inspection.

(See DTC TABLE [SKYACTIV-G 2.5].)

Go to the troubleshooting procedure to perform the procedure from Step 1.

No

Go to the troubleshooting procedure to perform the procedure from Step 1.


Troubleshooting Diagnostic Procedure



STEP

INSPECTION

RESULTS

ACTION

1

PURPOSE: VERIFY IF CAUSE OF MALFUNCTION IS RELATED TO LACK OF FUEL
  • Verify the remaining amount of fuel.

  • Is there a lack of fuel?

Yes

Refill the fuel, then go to Step 20.

No

Go to the next step.

2

PURPOSE: DETERMINE INTEGRITY OF FUEL PRESSURE SENSOR

Yes

Replace the fuel distributor, then go to Step 20.

(See FUEL INJECTOR REMOVAL/INSTALLATION [SKYACTIV-G 2.5].)

No

Go to the next step.

3

PURPOSE: DETERMINE INTEGRITY OF HIGH PRESSURE FUEL PUMP

Yes

Replace the high pressure fuel pump, then go to Step 20.

(See HIGH PRESSURE FUEL PUMP REMOVAL/INSTALLATION [SKYACTIV-G 2.5].)

No

Go to the next step.

4

PURPOSE: VERIFY IF MALFUNCTION RELATED TO FUEL LEAK FROM FUEL SYSTEM OR RESTRICTION AFFECTS DIAGNOSTIC RESULTS
  • Inspect the fuel system pipes (low to high pressure sides) for fuel leakage and restriction.

  • Is there any malfunction?

Yes

Repair or replace the malfunctioning part according to the inspection results, then go to Step 20.

No

Go to the next step.

5

PURPOSE: DETERMINE INTEGRITY OF FUEL PUMP CONTROL MODULE

Yes

Replace the fuel pump control module, then go to Step 20.

(See FUEL PUMP CONTROL MODULE REMOVAL/INSTALLATION [SKYACTIV-G 2.5].)

No

Go to the next step.

6

PURPOSE: DETERMINE INTEGRITY OF FUEL PUMP UNIT

Yes

Replace the fuel pump unit, then go to Step 20.

(See FUEL PUMP UNIT REMOVAL/INSTALLATION [SKYACTIV-G 2.5].)

No

Go to the next step.

7

PURPOSE: DETERMINE INTEGRITY OF FUEL INJECTOR

Yes

Replace the fuel injector, then go to Step 20.

(See FUEL INJECTOR REMOVAL/INSTALLATION [SKYACTIV-G 2.5].)

No

Go to the next step.

8

PURPOSE: DETERMINE INTEGRITY OF PURGE SOLENOID VALVE

Yes

Replace the purge solenoid valve, then go to Step 20.

(See PURGE SOLENOID VALVE REMOVAL/INSTALLATION [SKYACTIV-G 2.5].)

No

Go to the next step.

9

Yes

Replace the PCV valve, then go to Step 20.

(See POSITIVE CRANKCASE VENTILATION (PCV) VALVE REMOVAL/INSTALLATION [SKYACTIV-G 2.5].)

No

Go to the next step.

10

PURPOSE: DETERMINE INTEGRITY OF MAF SENSOR

Yes

Replace the MAF sensor/IAT sensor No.1, then go to Step 20.

(See MASS AIR FLOW (MAF) SENSOR/INTAKE AIR TEMPERATURE (IAT) SENSOR NO.1 REMOVAL/INSTALLATION [SKYACTIV-G 2.5].)

No

Go to the next step.

11

PURPOSE: VERIFY IF MALFUNCTION RELATED TO AIR CLEANER ELEMENT AFFECTS MEASUREMENT OF INTAKE AIR AMOUNT

Yes

Replace the air cleaner element, then go to Step 20.

(See AIR CLEANER ELEMENT REMOVAL/INSTALLATION [SKYACTIV-G 2.5].)

No

Go to the next step.

12

PURPOSE: DETERMINE INTEGRITY OF MAP SENSOR

Yes

Replace the MAP sensor/IAT sensor No.2, then go to Step 20.

(See MANIFOLD ABSOLUTE PRESSURE (MAP) SENSOR/INTAKE AIR TEMPERATURE (IAT) SENSOR NO.2 REMOVAL/INSTALLATION [SKYACTIV-G 2.5].)

No

Go to the next step.

13

PURPOSE: VERIFY IF MALFUNCTION RELATED TO INTAKE AIR SYSTEM AFFECTS DIAGNOSTIC RESULTS
  • Visually inspect for loose, cracked or damaged hoses on intake air system.

  • Is there any malfunction?

Yes

Repair or replace the malfunctioning part according to the inspection results, then go to Step 20.

No

Go to the next step.

14

PURPOSE: DETERMINE INTEGRITY OF ELECTRIC VARIABLE VALVE TIMING DRIVER

Yes

Replace the electric variable valve timing motor/driver, then go to Step 20.

(See ELECTRIC VARIABLE VALVE TIMING MOTOR/DRIVER REMOVAL/INSTALLATION [SKYACTIV-G 2.5].)

No

Go to the next step.

15

PURPOSE: DETERMINE INTEGRITY OF ELECTRIC VARIABLE VALVE TIMING MOTOR

Yes

Replace the electric variable valve timing motor/driver, then go to Step 20.

(See ELECTRIC VARIABLE VALVE TIMING MOTOR/DRIVER REMOVAL/INSTALLATION [SKYACTIV-G 2.5].)

No

Go to the next step.

16

PURPOSE: DETERMINE INTEGRITY OF ELECTRIC VARIABLE VALVE TIMING ACTUATOR

Yes

Replace the electric variable valve timing actuator, then go to Step 20.

(See ELECTRIC VARIABLE VALVE TIMING ACTUATOR, HYDRAULIC VARIABLE VALVE TIMING ACTUATOR REMOVAL/INSTALLATION [SKYACTIV-G 2.5].)

No

Go to the next step.

17

PURPOSE: DETERMINE INTEGRITY OF OCV

Yes

Replace the OCV, then go to Step 20.

(See OIL CONTROL VALVE (OCV) REMOVAL/INSTALLATION [SKYACTIV-G 2.5].)

No

Go to the next step.

18

PURPOSE: DETERMINE INTEGRITY OF A/F SENSOR

Yes

Replace the A/F sensor, then go to Step 20.

(See AIR FUEL RATIO (A/F) SENSOR REMOVAL/INSTALLATION [SKYACTIV-G 2.5].)

No

Go to the next step.

19

PURPOSE: VERIFY IF MALFUNCTION RELATED TO EMISSION SYSTEM AFFECTS HO2S SIGNAL
  • Verify the exhaust gas leakage from the exhaust system. (between A/F sensor and HO2S)

  • Is there any malfunction?

Yes

Repair or replace the malfunctioning part according to the inspection results, then go to Step 24.

No

Go to the next step.

20

PURPOSE: VERIFICATION OF VEHICLE REPAIR COMPLETION

Yes

Repeat the inspection from Step 1.

Go to the next step.

No

Go to the next step.

21

PURPOSE: VERIFY IF THERE IS ANY OTHER MALFUNCTION
  • Is any other DTC or pending code stored?

Yes

Go to the applicable DTC inspection.

(See DTC TABLE [SKYACTIV-G 2.5].)

No

DTC troubleshooting completed.




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