SFI SYSTEM(w/o Canister Pump Module), Diagnostic DTC:P0171, P0172, P0174, P0175, P1170, P117B

DTC Code	DTC Name
P0171	System Too Lean (Bank 1)
P0172	System Too Rich (Bank 1)
P0174	System Too Lean (Bank 2)
P0175	System Too Rich (Bank 2)
P1170	Fuel Performance / Port Injector
P117B	Fuel Performance / Direct Injector

DESCRIPTION

The fuel trim is related to the feedback compensation value, not to the basic injection duration. The fuel trim consists of both the short-term and long-term fuel trims.

The short-term fuel trim is fuel compensation that is used to constantly maintain the air fuel ratio at stoichiometric levels. The signal from the air fuel ratio sensor indicates whether the air fuel ratio is rich or lean compared to the stoichiometric ratio. This triggers a reduction in the fuel injection volume if the air fuel ratio is rich and an increase in the fuel injection volume if lean.

Factors such as individual engine differences, wear over time and changes in operating environment cause short-term fuel trim to vary from the central value. The long-term fuel trim, which controls overall fuel compensation, compensates for long-term deviations in the fuel trim from the central value caused by the short-term fuel trim compensation.

DTC No.	Detection Item	DTC Detection Condition	Trouble Area	MIL	Memory
P0171	System Too Lean (Bank 1)	With a warm engine and stable air fuel ratio feedback, the fuel trim is considerably in error to the lean side (2 trip detection logic).	Intake system Fuel injector assembly (for port injection) Fuel injector assembly (for direct injection) Mass air flow meter sub-assembly Engine coolant temperature sensor Fuel pressure Fuel delivery pipe sub-assembly (fuel pressure sensor) Injector driver (EDU) Gas leak from exhaust system Open or short in air fuel ratio sensor (bank 1 sensor 1) circuit Air fuel ratio sensor (bank 1 sensor 1) PCV valve and hose PCV hose connections Wire harness or connector ECM	Comes on (Euro-OBD) / - (Except Euro-OBD)	DTC stored (Euro-OBD) / - (Except Euro-OBD)
P0172	System Too Rich (Bank 1)	With a warm engine and stable air fuel ratio feedback, the fuel trim is considerably in error to the rich side (2 trip detection logic).	Fuel injector assembly (for port injection) Fuel injector assembly (for direct injection) Mass air flow meter sub-assembly Engine coolant temperature sensor Ignition system Fuel pressure Fuel delivery pipe sub-assembly (fuel pressure sensor) Injector driver (EDU) Gas leak from exhaust system Open or short in air fuel ratio sensor (bank 1 sensor 1) circuit Air fuel ratio sensor (bank 1 sensor 1) Wire harness or connector ECM	Comes on (Euro-OBD) / - (Except Euro-OBD)	DTC stored (Euro-OBD) / - (Except Euro-OBD)
P0174	System Too Lean (Bank 2)	With a warm engine and stable air fuel ratio feedback, the fuel trim is considerably in error to the lean side (2 trip detection logic).	Intake system Fuel injector assembly (for port injection) Fuel injector assembly (for direct injection) Mass air flow meter sub-assembly Engine coolant temperature sensor Fuel pressure Fuel delivery pipe sub-assembly (fuel pressure sensor) Injector driver (EDU) Gas leak from exhaust system Open or short in air fuel ratio sensor (bank 2 sensor 1) circuit Air fuel ratio sensor (bank 2 sensor 1) PCV valve and hose PCV hose connections Wire harness or connector ECM	Comes on (Euro-OBD) / - (Except Euro-OBD)	DTC stored (Euro-OBD) / - (Except Euro-OBD)
P0175	System Too Rich (Bank 2)	With a warm engine and stable air fuel ratio feedback, the fuel trim is considerably in error to the rich side (2 trip detection logic).	Fuel injector assembly (for port injection) Fuel injector assembly (for direct injection) Mass air flow meter sub-assembly Engine coolant temperature sensor Ignition system Fuel pressure Fuel delivery pipe sub-assembly (fuel pressure sensor) Injector driver (EDU) Gas leak from exhaust system Open or short in air fuel ratio sensor (bank 2 sensor 1) circuit Air fuel ratio sensor (bank 2 sensor 1) Wire harness or connector ECM	Comes on (Euro-OBD) / - (Except Euro-OBD)	DTC stored (Euro-OBD) / - (Except Euro-OBD)
P1170	Fuel Performance / Port Injector	Although a DTC is stored for a rich or lean condition, the amount of fuel trim during direct injection is normal (1 trip detection logic)	Fuel injector assembly (for port injection) Fuel injector assembly (for direct injection) Fuel pressure ECM	Does not come on (Euro-OBD) / - (Except Euro-OBD)	DTC stored (Euro-OBD) / - (Except Euro-OBD)
P117B	Fuel Performance / Direct Injector	Although a DTC is stored for a rich or lean condition, the amount of fuel trim during port injection is normal (1 trip detection logic)	Fuel injector assembly (for port injection) Fuel injector assembly (for direct injection) Fuel pressure ECM	Does not come on (Euro-OBD) / - (Except Euro-OBD)	DTC stored (Euro-OBD) / - (Except Euro-OBD)

Tech Tips

When DTC P0171 or P0174 is stored, the actual air fuel ratio is on the lean side. When DTC P0172 or P0175 is stored, the actual air fuel ratio is on the rich side.
If the vehicle runs out of fuel, the air fuel ratio is lean and DTC P0171 or P0174 may be stored. The MIL is then illuminated.
When DTC P1170 or P117B is output, it may not be possible to precisely determine whether the port injection or the direct injection is malfunctioning, depending on the conditions. In this case, perform an Active Test (Control the Injection Way) to determine which injection system is malfunctioning.

MONITOR DESCRIPTION

Under closed loop fuel control, fuel injection volumes that deviate from those estimated by the ECM cause changes in the long-term fuel trim compensation value. The long-term fuel trim is adjusted when there are persistent deviations in the short-term fuel trim values. Deviations from the fuel injection volumes estimated by the ECM also affect the average fuel trim learned value, which is a combination of the average short-term fuel trim (fuel feedback compensation value) and the average long-term fuel trim (learned value of the air fuel ratio). If the average fuel trim learned value exceeds the malfunction thresholds, the ECM interprets this as a fault in the fuel system and stores a DTC.

Example:

The average fuel trim learned value is +42% or higher, or -35% or less, the ECM interprets this as a fuel system malfunction.

MONITOR STRATEGY

Required Sensors/Components (Main)

Fuel system

Required Sensors/Components (Related)

Air fuel ratio sensor

Mass air flow meter sub-assembly

Crankshaft position sensor

Frequency of Operation

Continuous

TYPICAL ENABLING CONDITIONS

Fuel system status	Closed loop
Battery voltage	11 V or higher
Either of the following conditions is met	1 or 2
1. Engine speed	Less than 1100 rpm
2. Engine load	10% or higher

TYPICAL MALFUNCTION THRESHOLDS

P0171, P0172, P0174 and P0175: Fuel-Trim Lean/Rich
EVAP purge-cut	Executing
Either of the following conditions is met	1 or 2
1. Average between short-term fuel trim and long-term fuel trim	42% or higher (varies with engine coolant temperature)
2. Average between short-term fuel trim and long-term fuel trim	-35% or less (varies with engine coolant temperature)

P1170: Fuel Trim (Port Injection Fail)
DTCs of fuel system have already been set	-
EVAP purge-cut	Executing
Direct injection	100%
Both of the following conditions are met	1 and 2
1. Average between short-term fuel trim and long-term fuel trim	Less than 42% (varies with engine coolant temperature)
2. Average between short-term fuel trim and long-term fuel trim	Higher than -35% (varies with engine coolant temperature)

P117B: Fuel Trim (Direct Injection Fail)
DTCs of fuel system have already been set	-
EVAP purge-cut	Executing
Port injection	100%
Both of the following conditions are met	1 and 2
1. Average between short-term fuel trim and long-term fuel trim	Less than 42% (varies with engine coolant temperature)
2. Average between short-term fuel trim and long-term fuel trim	Higher than -35% (varies with engine coolant temperature)

CONFIRMATION DRIVING PATTERN

Connect the GTS to the DLC3.
Turn the engine switch on (IG) and turn the GTS on.
Clear the DTCs (even if no DTCs are stored, perform the clear DTC procedure).
Turn the engine switch off.
Tech Tips
- Let the engine cool down.
- Touch a radiator hose to check that the engine coolant temperature has dropped.
Turn the engine switch on (IG) and turn the GTS on [A].
Start the engine and warm it up until the engine coolant temperature is 75°C (167°F) or higher with all the accessories switched off [B].
Enter the following menus: Powertrain / Engine / Trouble Codes / Pending.
Read the pending DTCs [C].
Tech Tips
- If a pending DTC is output, the system is malfunctioning.
- If a pending DTC is not output, perform the following procedure.
Drive the vehicle at between 60 and 120 km/h (37 and 75 mph) and at an engine speed of between 1400 rpm and 3200 rpm for 5 minutes or more [D].

CAUTION:

When performing the confirmation driving pattern, obey all speed limits and traffic laws.
Enter the following menus: Powertrain / Engine / Trouble Codes / Pending.
Read the pending DTCs [E].
Tech Tips
- If a pending DTC is output, the system is malfunctioning.
- If a pending DTC is not output, the system is normal.

WIRING DIAGRAM

Refer to DTC P0102 for the mass air flow meter sub-assembly circuit.

Click here

Refer to DTC P2195 for the air fuel ratio sensor circuit.

Click here

CAUTION / NOTICE / HINT

Note

Inspect the fuses for circuits related to this system before performing the following procedure.

Tech Tips

Bank 1 refers to the bank that includes the No. 1 cylinder*.

*: The No. 1 cylinder is the cylinder which is farthest from the transmission.
Bank 2 refers to the bank that does not include the No. 1 cylinder.
Sensor 1 refers to the sensor closest to the engine assembly.
Sensor 2 refers to the sensor farthest away from the engine assembly.
A low air fuel ratio sensor voltage could be caused by a rich air fuel mixture. Check for conditions that would cause the engine to run rich.
A high air fuel ratio sensor voltage could be caused by a lean air fuel mixture. Check for conditions that would cause the engine to run lean.
Read freeze frame data using the GTS. The ECM records vehicle and driving condition information as freeze frame data the moment a DTC is stored. When troubleshooting, freeze frame data can help determine if the vehicle was moving or stationary, if the engine was warmed up or not, if the air fuel ratio was lean or rich, and other data from the time the malfunction occurred.

PROCEDURE

CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO DTC P0171, P0172, P0174, P0175, P1170 OR P117B)

Connect the GTS to the DLC3
Turn the engine switch on (IG).
Turn the GTS on.
Enter the following menus: Powertrain / Engine / Trouble Codes.

Read the DTCs.

Powertrain > Engine > Trouble Codes

Result

Result	Proceed to
DTC P0171, P0172, P0174, P0175, P1170 or P117B is output	A
DTC P0171, P0172, P0174, P0175, P1170 and/or P117B and other DTCs are output	B

Tech Tips

If any DTCs other than P0171, P0172, P0174, P0175, P1170 or P117B are output, troubleshoot those DTCs first.

GO TO DTC CHART Click here

PERFORM ACTIVE TEST USING GTS (CONTROL THE INJECTION WAY)

Connect the GTS to the DLC3.
Turn the engine switch on (IG).
Turn the GTS on.
Start the engine and warm it up.

Enter the following menus: Powertrain / Engine / Active Test / Control the Injection Way / Port / Injection Way, Short FT #1 and Long FT #1 and/or Short FT #2 and Long FT #2.

Powertrain > Engine > Active Test

Active Test Display
Control the Injection Way

Data List Display
Injection Way
Short FT #1
Long FT #1
Short FT #2
Long FT #2

Read the values displayed on the GTS.

OK

Short FT #1 (#2) + Long FT #1 (#2) = Between -19% and +19% (Port injection)

OK
Short FT #1 (#2) + Long FT #1 (#2) = Between -19% and +19% (Port injection)

Enter the following menus: Powertrain / Engine / Active Test / Control the Injection Way / Direct / Injection Way, Short FT #1 and Long FT #1 and/or Short FT #2 and Long FT #2.

Powertrain > Engine > Active Test

Active Test Display
Control the Injection Way

Data List Display
Injection Way
Short FT #1
Long FT #1
Short FT #2
Long FT #2

Read the values displayed on the GTS.

OK
Short FT #1 (#2) + Long FT #1 (#2) = Between -19% and +19% (Direct injection)

Result

Item		Proceed to
Port	Direct	Proceed to
OK	OK	A
OK	NG	B
NG	OK	C
NG	NG	D

READ VALUE USING GTS (FUEL PRESS) Click here

INSPECT FUEL INJECTOR ASSEMBLY (FOR PORT INJECTION) Click here

CHECK PCV HOSE CONNECTIONS Click here

CHECK IF VEHICLE HAS RUN OUT OF FUEL IN PAST

Has the vehicle run out of fuel in the past?

Result

Proceed to
YES
NO

YES

DTC CAUSED BY RUNNING OUT OF FUEL

CHECK FOR INTERMITTENT PROBLEMS Click here

READ VALUE USING GTS (FUEL PRESS)

Connect the GTS to the DLC3.
Start the engine.
Turn the GTS on.
Enter the following menus: Powertrain / Engine / Data List / All Data / Fuel Press.

Powertrain > Engine > Data List

Tester Display

Fuel Press

Tester Display
Fuel Press

Read the values.

Standard
Idling
3500 to 4500 kPag.
2000 rpm
7000 to 9000 kPag.
3000 rpm
7000 to 9000 kPag.

Tech Tips

The A/C switch and all accessory switches should be off, and the shift lever should be in the P position, and the engine should be fully warmed up.

Result

Proceed to
OK
NG

CHECK MISFIRE COUNT OF DIRECT INJECTION Click here

PERFORM ACTIVE TEST USING GTS (CONTROL THE INJECTION WAY (DIRECT))

Connect the GTS to the DLC3.
Start the engine and warm it up.
Turn the GTS on.

Enter the following menus: Powertrain / Engine / Active Test / Control the Injection Way / Direct / Injection Way, Short FT #1, Long FT #1, Short FT #2, Long FT #2 and Fuel Pump Duty (D4).

Powertrain > Engine > Active Test

Active Test Display
Control the Injection Way

Data List Display
Fuel Pump Duty (D4)
Injection Way
Short FT #1
Long FT #1
Short FT #2
Long FT #2

Read the values displayed on the GTS.

Tech Tips

The A/C switch and all accessory switches should be off, and the shift lever should be in the P position, and the engine should be fully warmed up.

Result

Item			Proceed to
Fuel Pump Duty (D4)	Short FT #1 + Long FT #1	Short FT #2 + Long FT #2	Proceed to
10% to 40%	-	-	A
40% or higher	-20% or less	-20% or less	B
10% or less	+20% or higher	+20% or higher	B
40% or higher	+20% or higher	+20% or higher	C
10% or less	-20% or less	-20% or less	D

REPLACE FUEL DELIVERY PIPE SUB-ASSEMBLY (FUEL PRESSURE SENSOR) Click here

GO TO STEP 9 Click here

REPLACE ECM Click here

PERFORM ACTIVE TEST USING GTS (CONTROL THE INJECTION WAY (DIRECT))

Connect the GTS to the DLC3.
Start the engine and warm it up.
Turn the GTS on.

Enter the following menus: Powertrain / Engine / Active Test / Control the Injection Way / Direct / Injection Way, Short FT #1, Long FT #1, Short FT #2, Long FT #2 and Fuel Pump Duty (D4).

Powertrain > Engine > Active Test

Active Test Display
Control the Injection Way

Data List Display
Fuel Pump Duty (D4)
Injection Way
Short FT #1
Long FT #1
Short FT #2
Long FT #2

Read the values displayed on the GTS

Tech Tips

The A/C switch and all accessory switches should be off, and the shift lever should be in the P position, and the engine should be fully warmed up.

Result

Item			Proceed to
Fuel Pump Duty (D4)	Short FT #1 + Long FT #1	Short FT #2 + Long FT #2	Proceed to
10% to 40%	-25% or less	-25% or less	A
10% to 40%	-25% or less	-25% to +25%	B
10% to 40%	-25% to +25%	-25% or less	C
10% to 40%	+30% or higher	+30% or higher	A
10% to 40%	+25% or higher	-25% to +25%	B
10% to 40%	-25% to +25%	+25% or higher	C
10% to 40%	-25% to +25%	-25% to +25%	D

REPLACE FUEL INJECTOR ASSEMBLY (FOR DIRECT INJECTION (ALL CYLINDERS)) Click here

REPLACE FUEL INJECTOR ASSEMBLY (FOR DIRECT INJECTION (BANK 1)) Click here

REPLACE FUEL INJECTOR ASSEMBLY (FOR DIRECT INJECTION (BANK 2)) Click here

CHECK FOR INTERMITTENT PROBLEMS Click here

CHECK MISFIRE COUNT OF DIRECT INJECTION

Connect the GTS to the DLC3.
Turn the engine switch on (IG).
Turn the GTS on.
Start the engine and warm it up.

Enter the following menus: Powertrain / Engine / Active test / Control the Injection Way / Direct / Injection Way and Cylinder #1 Misfire Count to Cylinder #6 Misfire Count.

Powertrain > Engine > Active Test

Active Test Display
Control the Injection Way

Data List Display
Injection Way
Cylinder #1 Misfire Count
Cylinder #2 Misfire Count
Cylinder #3 Misfire Count
Cylinder #4 Misfire Count
Cylinder #5 Misfire Count
Cylinder #6 Misfire Count

Allow the engine to idle.

Monitor all of the misfire count values that are displayed on the GTS.

Result

Injection Way	Misfire Count	Proceed to
Direct	No misfire counts, or misfire counts occur randomly in all cylinders	A
Direct	Misfire counts occur in particular cylinder	B

REPLACE FUEL INJECTOR ASSEMBLY (FOR DIRECT INJECTION) Click here

INSPECT INJECTOR DRIVER (EDU)

Replace the injector driver (EDU) with known good ones from another vehicle.

Note

Do not disconnect and reconnect the connectors with the engine switch on (IG), as the injector driver (EDU) may be damaged.
Connect the GTS to the DLC3.
Turn the engine switch on (IG).
Turn the GTS on.
Clear the DTCs.

Click here

Powertrain > Engine > Clear DTCs
Turn the engine switch off and wait for at least 30 seconds.
Turn the engine switch on (IG) and turn the GTS on.
Start the engine and warm it up.
Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.
Enter the following menus: Powertrain / Engine / Trouble Codes.

Read the pending DTCs.

Powertrain > Engine > Trouble Codes

Result

Result	Proceed to
P0171, P0172, P0174, P0175, P1170 and/or P117B is output	A
DTCs are not output	B

END (INJECTOR DRIVER WAS DEFECTIVE)

READ VALUE USING GTS (FUEL PRESS)

Connect the GTS to the DLC3.
Turn the engine switch on (IG).
Turn the GTS on.
Start the engine.
Enter the following menus: Powertrain / Engine / Data List / All Data / Fuel Press.

Powertrain > Engine > Data List

Tester Display

Fuel Press
Record the Fuel Press value.
Turn the engine switch off.
Wait for 10 seconds.
Turn the engine switch on (IG) and turn the GTS on.
Enter the following menus: Powertrain / Engine / Data List / All Data / Fuel Press.

Powertrain > Engine > Data List

Tester Display

Fuel Press

Compare the Fuel Press value recorded with the engine running to the Fuel Press value currently shown on the GTS.

Result

Result	Proceed to
Fuel Press value is maintained	A
Fuel Press value drops	B

REPLACE FUEL PUMP (FOR HIGH PRESSURE SIDE) Click here

REPLACE FUEL RELIEF VALVE ASSEMBLY Click here

INSPECT FUEL INJECTOR ASSEMBLY (FOR PORT INJECTION)

Check the injection volume (whether fuel volume is high or low, and whether injection pattern is poor).

Result

Proceed to
OK
NG

REPLACE ECM Click here

REPLACE FUEL INJECTOR ASSEMBLY (FOR PORT INJECTION) Click here

CHECK PCV HOSE CONNECTIONS

Check the PCV hose connections.

Click here

OK
PCV valve and hose are connected correctly and are not damaged.

Result

Proceed to
OK
NG

REPAIR OR REPLACE PCV HOSE

CHECK INTAKE SYSTEM

Check the intake system for vacuum leaks.

Click here

OK
No leaks in intake system.

Tech Tips

If a malfunction is detected while the brake pedal is being depressed, vacuum leaks in the brake booster assembly are suspected. Inspect the brake booster assembly.

Result

Proceed to
OK
NG

REPAIR OR REPLACE INTAKE SYSTEM

PERFORM ACTIVE TEST USING GTS (CONTROL THE INJECTION VOLUME FOR A/F SENSOR)

Connect the GTS to the DLC3.
Start the engine.
Turn the GTS on.
Warm up the engine and run the engine at an engine speed of 2500 rpm for approximately 90 seconds.

Enter the following menus: Powertrain / Engine / Active Test / Control the Injection Volume for A/F Sensor / Gas AF Control / AFS Voltage B1S1 and O2S B1S2 or AFS Voltage B2S1 and O2S B2S2.

Powertrain > Engine > Active Test

Active Test Display
Control the Injection Volume for A/F Sensor

Data List Display
AFS Voltage B1S1
AFS Voltage B2S1
O2S B1S2
O2S B2S2

Perform the Control the Injection Volume for A/F Sensor operation with the engine idling (press the RIGHT or LEFT button to change the fuel injection volume).

Monitor the voltage outputs of the air fuel ratio sensor and the heated oxygen sensor (AFS Voltage B1S1 and O2S B1S2 or AFS Voltage B2S1 and O2S B2S2) displayed on the GTS.

Tech Tips

Change the injection volume operation lowers the fuel injection volume by 12.5% or increases the injection volume by 12.5%.
The air fuel ratio sensor has an output delay of a few seconds and the heated oxygen sensor has a maximum output delay of approximately 20 seconds.
If the sensor output voltage does not change (almost no reaction) while performing the Active Test, the sensor may be malfunctioning.

Standard

GTS Display (Sensor)	Injection Volume	Status	Voltage
AFS Voltage B1S1 AFS Voltage B2S1 (Air fuel ratio)	12.5%	Rich	Below 3.1 V
AFS Voltage B1S1 AFS Voltage B2S1 (Air fuel ratio)	-12.5%	Lean	Higher than 3.4 V
O2S B1S2 O2S B2S2 (Heated oxygen)	12.5%	Rich	Higher than 0.55 V
O2S B1S2 O2S B2S2 (Heated oxygen)	-12.5%	Lean	Below 0.4 V

Result

Status AFS Voltage B1S1 or AFS Voltage B2S1	Status O2S B1S2 or O2S B2S2	Air Fuel Ratio Condition and Air Fuel Ratio Sensor Condition	Suspected Trouble Area	Proceed to
Lean/Rich	Lean/Rich	Normal	-	A
Lean	Lean	Actual air fuel ratio lean	PCV valve and hose PCV hose connections Gas leak from exhaust system Intake system Fuel pressure Mass air flow meter sub-assembly Engine coolant temperature sensor
Rich	Rich	Actual air fuel ratio rich	Gas leak from exhaust system Ignition system Fuel pressure Mass air flow meter sub-assembly Engine coolant temperature sensor
Lean	Lean/Rich	Air fuel ratio sensor malfunction	Air fuel ratio sensor	B
Rich	Lean/Rich	Air fuel ratio sensor malfunction	Air fuel ratio sensor	B

Lean: During Control the Injection Volume for A/F Sensor, the air fuel ratio sensor output voltage (AFS Voltage B1S1 or AFS Voltage B2S1) is consistently higher than 3.4 V, and the heated oxygen sensor output voltage (O2S B1S2 or O2S B2S2) is consistently below 0.4 V.
Rich: During Control the Injection Volume for A/F Sensor, the AFS Voltage B1S1 or AFS Voltage B2S1 is consistently below 3.1 V, and the O2S B1S2 or O2S B2S2 is consistently higher than 0.55 V.
Lean/Rich: During Control the Injection Volume for A/F Sensor of the Active Test, the output voltage of the air fuel ratio sensor or heated oxygen sensor alternates correctly.

Tech Tips

Refer to "Data List / Active Test" [AFS Voltage B1S1, AFS Voltage B2S1, O2S B1S2 and O2S B2S2].

Click here

INSPECT AIR FUEL RATIO SENSOR (HEATER RESISTANCE) Click here

READ VALUE USING GTS (COOLANT TEMP)

Connect the GTS to the DLC3.
Turn the engine switch on (IG).
Turn the GTS on.
Enter the following menus: Powertrain / Engine / Data List / All Data / Coolant Temp.

Powertrain > Engine > Data List

Tester Display

Coolant Temp

Read the Data List twice, when the engine is both cold and warmed up.

Standard

GTS Display	Condition	Specified Condition
Coolant Temp	Cold engine	Same as ambient air temperature
Coolant Temp	Warm engine	Between 75 and 100°C (167 and 212°F)

Result

Proceed to
OK
NG

REPLACE ENGINE COOLANT TEMPERATURE SENSOR Click here

READ VALUE USING GTS (MAF)

Connect the GTS to the DLC3.
Start the engine.
Turn the GTS on.

Enter the following menus: Powertrain / Engine / Data List / All Data / MAF, Coolant Temp and Engine Speed.

Powertrain > Engine > Data List

Tester Display
Engine Speed
MAF
Coolant Temp

Allow the engine to idle until Coolant Temp reaches 75°C (167°F) or higher.

Read MAF with the engine speed at 3000 rpm.

Standard

GTS Display

Condition

Specified Condition

MAF

Shift lever position: P

A/C: Off

Engine Speed: 3000 rpm

Between 10.6 gm/sec and 15.8 gm/sec

Result

Proceed to
OK
NG

GO TO STEP 24 Click here

CHECK FOR EXHAUST GAS LEAK

Check for exhaust gas leaks.

OK
No gas leaks.

Result

Proceed to
OK
NG

REPAIR OR REPLACE EXHAUST SYSTEM

CHECK FUEL PRESSURE (FOR LOW PRESSURE SIDE)

Check the fuel pressure (for low pressure side).

Click here

Result

Proceed to
OK
NG

GO TO STEP 23 Click here

CHECK FUEL PUMP OPERATION (FOR LOW PRESSURE SIDE)

Check the fuel pump operation (for low pressure side).

Click here

Result

Proceed to
OK
NG

REPLACE FUEL PUMP (FOR LOW PRESSURE SIDE) Click here

CHECK FUEL LEAK (FOR LOW PRESSURE SIDE)

Check for fuel leaks (for low pressure side).

OK
No leaks.

Result

Proceed to
OK
NG

CHECK AND REPLACE FUEL PUMP, PRESSURE REGULATOR, FUEL LINE AND FILTER

REPAIR OR REPLACE FUEL SYSTEM (FOR LOW PRESSURE SIDE)

INSPECT AIR FUEL RATIO SENSOR (HEATER RESISTANCE)

Inspect the air fuel ratio sensor.

Click here

Result

Proceed to
OK
NG

REPLACE AIR FUEL RATIO SENSOR Click here

CHECK HARNESS AND CONNECTOR (AIR FUEL RATIO SENSOR - ECM)

Result

Proceed to
OK
NG

Disconnect the air fuel ratio sensor connector.
Disconnect the ECM connector.

Measure the resistance according to the value(s) in the table below.

Standard Resistance

Tester Connection	Condition	Specified Condition
F52-1 (HA1A) - F4-5 (HA1A)	Always	Below 1 Ω
F52-3 (A1A+) - F3-23 (A1A+)	Always	Below 1 Ω
F52-4 (A1A-) - F3-22 (A1A-)	Always	Below 1 Ω
F41-1 (HA2A) - F4-6 (HA2A)	Always	Below 1 Ω
F41-3 (A2A+) - F3-21 (A2A+)	Always	Below 1 Ω
F41-4 (A2A-) - F3-20 (A2A-)	Always	Below 1 Ω
F52-1 (HA1A) or F4-5 (HA1A) - Body ground	Always	10 kΩ or higher
F52-3 (A1A+) or F3-23 (A1A+) - Body ground	Always	10 kΩ or higher
F52-4 (A1A-) or F3-22 (A1A-) - Body ground	Always	10 kΩ or higher
F41-1 (HA2A) or F4-6 (HA2A) - Body ground	Always	10 kΩ or higher
F41-3 (A2A+) or F3-21 (A2A+) - Body ground	Always	10 kΩ or higher
F41-4 (A2A-) or F3-20 (A2A-) - Body ground	Always	10 kΩ or higher

Result

Proceed to
OK
NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

REPLACE AIR FUEL RATIO SENSOR

Replace the air fuel ratio sensor.

Click here

Result

Proceed to
NEXT

CHECK WHETHER DTC OUTPUT RECURS (DTC P0171, P0172, P0174, P0175, P1170 OR P117B)

Connect the GTS to the DLC3.
Turn the engine switch on (IG).
Turn the GTS on.
Clear the DTCs.

Click here

Powertrain > Engine > Clear DTCs
Turn the engine switch off and wait for at least 30 seconds.
Turn the engine switch on (IG).
Turn the GTS on.
Start the engine and warm it up.
Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.
Enter the following menus: Powertrain / Engine / Trouble Codes.

Read the DTCs.

Powertrain > Engine > Trouble Codes

Result

Result	Proceed to
DTC P0171, P0172, P0174, P0175, P1170 and/or P117B is output	A
DTCs are not output	B

END

CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER SUB-ASSEMBLY CONNECTOR CONNECTION)

Check the connection and terminal contact pressure of connectors and wire harnesses between the mass air flow meter sub-assembly and ECM.

Click here

Tech Tips

Repair any problems.

Result

Proceed to
NEXT

CHECK WHETHER DTC OUTPUT RECURS (DTC P0171, P0172, P0174, P0175, P1170 OR P117B)

Connect the GTS to the DLC3.
Turn the engine switch on (IG).
Turn the GTS on.
Clear the DTCs.

Click here

Powertrain > Engine > Clear DTCs
Turn the engine switch off and wait for at least 30 seconds.
Turn the engine switch on (IG).
Turn the GTS on.
Start the engine and warm it up.
Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.
Enter the following menus: Powertrain / Engine / Trouble Codes.

Read the DTCs.

Powertrain > Engine > Trouble Codes

Result

Result	Proceed to
DTC P0171, P0172, P0174, P0175, P1170 or P117B is output	A
DTCs are not output	B

END

CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER SUB-ASSEMBLY - ECM)

Result

Proceed to
OK
NG

Disconnect the mass air flow meter sub-assembly connector.
Disconnect the ECM connector.

Measure the resistance according to the value(s) in the table below.

Standard Resistance

Tester Connection	Condition	Specified Condition
F38-5 (VG) - F1-25 (VG)	Always	Below 1 Ω
F38-4 (E2G) - F1-24 (E2G)	Always	Below 1 Ω
F38-5 (VG) or F1-25 (VG) - Body ground	Always	10 kΩ or higher

Result

Proceed to
OK
NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

REPLACE MASS AIR FLOW METER SUB-ASSEMBLY

Replace the mass air flow meter sub-assembly.

Click here

Tech Tips

If the result of the inspection performed in step 15 indicated no problem, proceed to the next step without replacing the mass air flow meter sub-assembly.

Result

Proceed to
NEXT

CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED

Connect the GTS to the DLC3.
Turn the engine switch on (IG).
Turn the GTS on.
Clear the DTCs.

Click here

Powertrain > Engine > Clear DTCs
Turn the engine switch off and wait for at least 30 seconds.
Turn the engine switch on (IG).
Turn the GTS on.
Start the engine and warm it up.
Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.
Enter the following menus: Powertrain / Engine / Trouble Codes.

Read the DTCs.

Powertrain > Engine > Trouble Codes

Result

Result	Proceed to
DTCs are not output	A
DTC P0171, P0172, P0174, P0175, P1170 or P117B is output	B

END

REPLACE ECM Click here