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DTC P0171:00 [PCM (SKYACTIV-G (WITHOUT CYLINDER DEACTIVATION (US)))]

DTC P0171:00 [PCM (SKYACTIV-G (WITHOUT CYLINDER DEACTIVATION (US)))]

SM2565577


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Note
• To determine the malfunctioning part, proceed with the diagnostics from “Function Inspection Using M-MDS”.



Details On DTCs

Description

Fuel trim system too lean

Detection condition
Determination conditions
• Any one of the following conditions is met:
― The sum of the fuel feedback correction amount (SHRT_FUEL_TRIM) and the fuel learning correction amount (LONG_FUEL_TRIM) is the specified value ( 30 %) or more, and 10 s or more have elapsed with the fuel learning correction amount (LONG_FUEL_TRIM) at the specified value ( 15 %) 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: Standard 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
• Not applicable
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
• 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 malfunction (built-into high pressure fuel pump)
― 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

• Not applicable



Function Explanation (DTC Detection Outline)

• The PCM detects the oxygen concentration in the exhaust gas from the A/F sensor signal and performs fuel injection amount feedback to maintain the optimum air/fuel ratio. If a condition in which the feedback correction amount is large (fuel injection amount being increased) continues for the specified time, a feedback correction amount malfunction is determined, and a DTC is stored. The feedback correction amount has a “Fuel feedback correction amount” for the air/fuel ratio and a “Fuel learning correction amount” for fuel injector deterioration over time.
• “Fuel feedback correction amount (SHRT_FUEL_TRIM)” and “Fuel learning correction amount (LONG_FUEL_TRIM)” can be verified from the M-MDS PID item.
1. The sum of the fuel feedback correction amount (SHRT_FUEL_TRIM) and the fuel learning correction amount (LONG_FUEL_TRIM) is the specified value ( 30 %) or more, and 10 s or more have elapsed with the fuel learning correction amount (LONG_FUEL_TRIM) at the specified value ( 15 %) or more. Engine coolant temperature: 0—45 °C {32—113 °F}, 60 °C {140 °F} or more

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2. The fuel feedback correction amount reaches the upper limit ( 25% or more) for 20 s or more. Engine coolant temperature: 0—45 °C {32—113 °F}, 60 °C {140 °F} or more

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Repeatability Verification Procedure

1. Warm up the engine to allow the engine coolant temperature to reach 80 °C {176 °F} or more.
2. Start the engine and leave it idling for 1 min.

Note
• Match the engine coolant temperature in the recorded freeze frame data/snapshot data, the vehicle speed, and engine speed values to the best extent possible while driving the vehicle.
3. Try to reproduce the malfunction by driving the vehicle for 5 min based on the values in the freeze frame data/snapshot data.



PID Item/Simulation Item Used In Diagnosis

PID/DATA monitor item table

PIDs

Reference

APP_RELAT
ECT
ECT_VOLT
PRG_DUTY
FUEL_PUMP_REQ
FUEL_PRES
IAT2
MAF
MAP
MAP_VOLT
A/F_SEN_CUR
TP_RELAT
VLV_TIMING_ACT_EX
VLV_TIMING_DSD_EX
VLV_TIMING_ACT_IN
VLV_TIMING_DSD_IN

Simulation item table

Simulation items

Reference

FUEL_PUMP_REQ
INJ



Function Inspection Using M-MDS

Step

Inspection

Results

Action

1
PURPOSE: VERIFY RELATED REPAIR INFORMATION OR SERVICE INFORMATION AVAILABILITY
• Verify related Service Bulletins, on-line repair information, or Service Information availability.
• Is any related Information available?
Yes
Perform repair or diagnosis according to the available 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
• Is the DTC P0171:00 on freeze frame data?
Yes
Go to the next step.
No
Go to the troubleshooting procedure for DTC on freeze frame data.
3
PURPOSE: RECORD VEHICLE STATUS WHEN DTC WAS DETECTED TO UTILIZE WITH REPEATABILITY VERIFICATION
• Record the freeze frame data/snapshot data.

Note
• Recording can be facilitated using the screen capture function of the PC.
Go to the next step.
4
PURPOSE: VERIFY IF INPUT SIGNAL TO PCM AFFECTS FUEL INJECTION
• Start the engine.
• Access the following PIDs using the M-MDS: (See PID/DATA MONITOR INSPECTION.)
― ECT
― ECT_VOLT
― APP_RELAT
― TP_RELAT
• Is there any signal that is far out of specification? (See PID/DATA MONITOR TABLE [PCM (SKYACTIV-G (US))].)
Yes
Inspect the suspected sensor and related wiring harness.
• If there is any malfunction:
― Repair or replace the malfunctioning part.
― Go to Troubleshooting Diagnostic Procedure to perform the repair completion verification.
• 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 PID/DATA MONITOR INSPECTION.)
― FUEL_PRES
― FUEL_PUMP_REQ
― PRG_DUTY
― MAF
― MAP
― MAP_VOLT
― IAT2
― VLV_TIMING_ACT_EX
― VLV_TIMING_ACT_IN
• 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/IAT sensor No.2
― OCV
― Electric variable valve timing motor/driver
― PCM
Yes
Repair or replace the applicable connector parts.
Go to Troubleshooting Diagnostic Procedure to perform the repair completion verification.
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 warm it up completely.
• Access the FUEL_PRES PID using the M-MDS. (See PID/DATA MONITOR INSPECTION.)
• Is the FUEL_PRES PID value approx. 10 MPa {102 kgf/cm2, 1450 psi}?
Yes
Go to the next step.
No
FUEL_PRES PID value is lower than 10 MPa {102 kgf/cm2, 1450 psi}:
• Go to Troubleshooting Diagnostic Procedure to perform the procedure from Step 1.
FUEL_PRES PID value is higher than 10 MPa {102 kgf/cm2, 1450 psi}:
• Go to Step 8.
7
PURPOSE: VERIFY FUEL PRESSURE (LOW-SIDE) MALFUNCTION
Note
• Verify the fuel pressure on the low pressure side with the operation of the high pressure fuel pump turned off.
• Bleed the remaining pressure in the fuel line using the following procedure.
1. Switch the ignition off.
2. Disconnect the high pressure fuel pump connector.
3. Remove the fuel pump relay. (See RELAY LOCATION [(US)].)
4. Start the engine and wait until the engine stalls.
• Switch the ignition off.
• Install the fuel pump relay.
• Switch the ignition ON (engine off).
• Display PID FUEL_PRES and simulation item FUEL_PUMP_REQ using the M-MDS. (See PID/DATA MONITOR INSPECTION.) (See SIMULATION INSPECTION.)
• Turn simulation item FUEL_PUMP_REQ on.
• Is the FUEL_PRES PID value 475—555 kPa {4.85—5.65 kgf/cm2, 68.9—80.4 psi}?
Yes
Go to the next step.
No
Go to Troubleshooting Diagnostic 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 SIMULATION INSPECTION.)
― INJ
• 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 Troubleshooting Diagnostic Procedure to perform the procedure from Step 7.
9
PURPOSE: VERIFY IF MALFUNCTION CAUSED BY PURGE SOLENOID VALVE IMPROPER OPERATION
• Start the engine and idle it.
• Access the PRG_DUTY PID using the M-MDS. (See PID/DATA MONITOR INSPECTION.)
• Is the PRG_DUTY PID value normal?
Yes
Go to the next step.
No
Go to Troubleshooting Diagnostic Procedure to perform the procedure from Step 8.
10
PURPOSE: VERIFY MAF SENSOR
• Start the engine and idle it.
• Access the MAF PID using the M-MDS. (See PID/DATA MONITOR INSPECTION.)
• Is the MAF PID value normal?
Yes
Go to the next step.
No
Go to Troubleshooting Diagnostic Procedure to perform the procedure from Step 10.
11
PURPOSE: VERIFY MAP SENSOR
• Start the engine and idle it.
• Access the following PIDs using the M-MDS: (See PID/DATA MONITOR INSPECTION.)
― MAP
― MAP_VOLT
• Are all items normal?
Yes
Go to the next step.
No
Go to Troubleshooting Diagnostic 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 PID/DATA MONITOR INSPECTION.)
― VLV_TIMING_ACT_IN
― VLV_TIMING_DSD_IN
• Depress the accelerator pedal to increase the engine speed.
• Does the monitor value of the PID item VLV_TIMING_ACT_IN conform to the VLV_TIMING_DSD_IN PID value?
Yes
Go to the next step.
No
Go to Troubleshooting Diagnostic 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 PID/DATA MONITOR INSPECTION.)
― VLV_TIMING_ACT_EX
― VLV_TIMING_DSD_EX
• Perform the following:
1. Warm up the engine to allow the engine coolant temperature to reach 80 °C {176 °F} or more.
2. Shift to 2nd gear (MTX)/D position (ATX) and rapidly accelerate the vehicle to 50 km/h {31 mph} (to operate hydraulic variable valve timing control).
3. Decelerate to idling.
4. Shift to 2nd gear (MTX)/D position (ATX) and rapidly accelerate the vehicle to 50 km/h {31 mph} again.
• Does the monitor value of the PID item VLV_TIMING_ACT_EX conform to the VLV_TIMING_DSD_EX PID value?
Yes
Go to the next step.
No
Go to Troubleshooting Diagnostic Procedure to perform the procedure from Step 17.
14
PURPOSE: VERIFY A/F SENSOR
• Access the A/F_SEN_CUR PID using the M-MDS. (See PID/DATA MONITOR INSPECTION.)
• Is the A/F_SEN_CUR PID value normal?
Yes
Go to the next step.
No
Go to Troubleshooting Diagnostic Procedure to perform the procedure from Step 18.
15
PURPOSE: INSPECT FOR OTHER RELATED DTCs
• Perform the DTC inspection for the PCM. (See DTC INSPECTION.)
• Are any other DTCs displayed?
Yes
Repair the malfunctioning location according to the applicable DTC troubleshooting.
Go to Troubleshooting Diagnostic Procedure to perform the procedure from Step 1.
No
Go to Troubleshooting Diagnostic Procedure to perform the procedure from Step 1.



Troubleshooting Diagnostic Procedure

Intention of troubleshooting procedure
• Step 1—7
― Perform a fuel injector control system inspection.
• Step 8—9
― Perform an emission system parts inspection.
• Step 10—13
― Perform an intake air system parts inspection.
• Step 14—17
― Perform a valve timing inspection.
• Step 18—19
― Perform an exhaust system parts inspection.
• Repair completion verification
― Verify that the primary malfunction is resolved and there are no other malfunctions.

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 and perform the repair completion verification.
No
Go to the next step.
2
PURPOSE: INSPECT FUEL PRESSURE SENSOR FOR MALFUNCTION
• Is the part normal?
Yes
Go to the next step.
No
Repair or replace the malfunctioning location and perform the repair completion verification.
3
PURPOSE: INSPECT HIGH PRESSURE FUEL PUMP FOR MALFUNCTION
• Is the part normal?
Yes
Go to the next step.
No
Repair or replace the malfunctioning location and perform the repair completion verification.
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 location and perform the repair completion verification.
No
Go to the next step.
5
PURPOSE: INSPECT FUEL PUMP CONTROL MODULE FOR MALFUNCTION
• Is the part normal?
Yes
Go to the next step.
No
Repair or replace the malfunctioning location and perform the repair completion verification.
6
PURPOSE: INSPECT FUEL PUMP UNIT FOR MALFUNCTION
• Is the part normal?
Yes
Go to the next step.
No
Repair or replace the malfunctioning location and perform the repair completion verification.
7
PURPOSE: INSPECT FUEL INJECTOR FOR MALFUNCTION
• Is the part normal?
Yes
Go to the next step.
No
Repair or replace the malfunctioning location and perform the repair completion verification.
8
PURPOSE: INSPECT PURGE SOLENOID VALVE FOR MALFUNCTION
• Is the part normal?
Yes
Go to the next step.
No
Repair or replace the malfunctioning location and perform the repair completion verification.
9
PURPOSE: INSPECT PCV VALVE FOR MALFUNCTION
• Is the part normal?
Yes
Go to the next step.
No
Repair or replace the malfunctioning location and perform the repair completion verification.
10
PURPOSE: INSPECT MAF SENSOR FOR MALFUNCTION
• Is the part normal?
Yes
Go to the next step.
No
Repair or replace the malfunctioning location and perform the repair completion verification.
11
PURPOSE: VERIFY IF MALFUNCTION RELATED TO AIR CLEANER ELEMENT AFFECTS MEASUREMENT OF INTAKE AIR AMOUNT
• Is the part normal?
Yes
Go to the next step.
No
Repair or replace the malfunctioning location and perform the repair completion verification.
12
PURPOSE: INSPECT MAP SENSOR FOR MALFUNCTION
• Is the part normal?
Yes
Go to the next step.
No
Repair or replace the malfunctioning location and perform the repair completion verification.
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 location and perform the repair completion verification.
No
Go to the next step.
14
PURPOSE: INSPECT ELECTRIC VARIABLE VALVE TIMING DRIVER FOR MALFUNCTION
• Is the part normal?
Yes
Go to the next step.
No
Repair or replace the malfunctioning location and perform the repair completion verification.
15
PURPOSE: INSPECT ELECTRIC VARIABLE VALVE TIMING MOTOR FOR MALFUNCTION
• Is the part normal?
Yes
Go to the next step.
No
Repair or replace the malfunctioning location and perform the repair completion verification.
16
PURPOSE: INSPECT ELECTRIC VARIABLE VALVE TIMING ACTUATOR FOR MALFUNCTION
• Is the part normal?
Yes
Go to the next step.
No
Repair or replace the malfunctioning location and perform the repair completion verification.
17
PURPOSE: INSPECT OCV FOR MALFUNCTION
• Is the part normal?
Yes
Go to the next step.
No
Repair or replace the malfunctioning location and perform the repair completion verification.
18
PURPOSE: INSPECT A/F SENSOR FOR MALFUNCTION
• Is the part normal?
Yes
Go to the next step.
No
Repair or replace the malfunctioning location and perform the repair completion verification.
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 location and perform the repair completion verification.
No
Go to the next step.
Repair completion verification
PURPOSE: VERIFY THAT VEHICLE IS REPAIRED
• Install/connect the part removed/disconnected during the troubleshooting procedure.
• Clear the DTC recorded in the memory. (See CLEARING DTC.)
• Replicate the vehicle conditions at the time the DTC was detected using the following procedure.
― Implement the repeatability verification procedure. (See Repeatability Verification Procedure.)
• Perform the DTC inspection for the PCM. (See DTC INSPECTION.)
• Is the same Pending DTC present?
Yes
Refer to the controller area network (CAN) malfunction diagnosis flow to inspect for a CAN communication error.
If the CAN communication is normal, perform the diagnosis from Step 1.
• If the malfunction recurs, replace the PCM. (See PCM REMOVAL/INSTALLATION [SKYACTIV-G (WITHOUT CYLINDER DEACTIVATION (US))].)
No
DTC troubleshooting completed.