P0171
2UR-FSE ENGINE CONTROL SYSTEM: SFI SYSTEM: P0171, P0172, P0174, P0175, P1170, P117B: System Too Lean (Bank 1)
P117B - Direct Injector Fuel Performance
DESCRIPTION
The fuel trim is related to the feedback compensation value, not to the basic injection time. The fuel trim consists of both the short-term and the long-term fuel trim.
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 (A/F) 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 it is lean.
Factors such as individual engine differences, wear over time and changes in operating environment cause short-term fuel trim to vary from the ideal theoretical value. The long-term fuel trim controls overall fuel compensation. The long-term fuel trim compensates for long term deviations of the fuel trim from the ideal theoretical value. These long term deviations result from the corrections made by the short-term fuel trim.
If both the short-term fuel and long-term fuel trims are lean or rich beyond predetermined values, it is interpreted as a malfunction, and the ECM illuminates the MIL and sets a DTC.
HINT
- When DTC P0171 or P0174 is set, the actual air-fuel ratio is on the lean side. When DTC P0172 or P0175 is set, 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 set. 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 ECM's estimated fuel injection volumes also affect the average fuel trim learning value, which is a combination of the average short-term fuel trim (fuel feedback compensation value) and the average long-term fuel trim (learning value of the air-fuel ratio). If the average fuel trim learning value exceeds the malfunction threshold, the ECM interprets this as a fault in the fuel system and sets a DTC.
- Example:
- If the average fuel trim learning value is 35% or more or -35% or less, the ECM interprets this as a fuel system malfunction.
MONITOR STRATEGY
TYPICAL ENABLING CONDITIONS
TYPICAL MALFUNCTION THRESHOLDS
Fuel-trim Lean/Rich (P0171, P0172, P0174, P0175):
Fuel Trim (Port Injection, P1170)
Fuel Trim (Direct Injection, P117B)
CONFIRMATION DRIVING PATTERN
1. Connect the Techstream to the DLC3.
2. Turn the power switch on (IG) and turn the Techstream on.
3. Clear the DTCs (even if no DTCs are stored, perform the clear DTC procedure) Reading and Clearing Diagnostic Trouble Codes.
4. Turn the power switch off.
HINT
- Let the engine cool down.
- Touch a radiator hose to check that the coolant temperature has dropped.
5. Turn the power switch on (IG) and turn the Techstream on [A].
6. Put the engine in inspection mode Inspection Mode Procedure.
7. Start the engine and warm it up until the engine coolant temperature is 75°C (167°F) or more with all the accessories switched off [B].
8. Enter the following menus: Powertrain / Engine and ECT / Trouble Codes / Pending.
9. Read the Pending DTCs [C].
HINT
- If a pending DTC is output, the system is malfunctioning.
- If a pending DTC is not output, perform the following procedure.
10. Drive the vehicle at a speed between 37 mph and 75 mph (60 km/h and 120 km/h) and at an engine speed of between 1400 rpm and 3200 rpm for 5 minutes or more [D].
11. Enter the following menus: Powertrain / Engine and ECT / Trouble Codes / Pending.
12. Read the Pending DTCs [E].
HINT
- If a pending DTC is output, the system is malfunctioning.
- If a pending DTC is not output, perform the following procedure.
13. Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.
14. Input the DTC: P0171, P0172, P0174 or P0175, P1170 or P117B.
15. Check the DTC judgment result.
CAUTION:
When performing the confirmation driving pattern, obey all speed limits and traffic laws.
HINT
- If the judgment result shows ABNORMAL, the system has a malfunction.
- If the judgment result shows INCOMPLETE or N/A, perform steps [B] through [E] again.
16. If the test result is INCOMPLETE or N/A and no pending DTC is output, perform a universal trip and check for permanent DTCs Reading and Clearing Diagnostic Trouble Codes.
HINT
- If a permanent DTC is output, the system is malfunctioning.
- If no permanent DTC is output, the system is normal.
WIRING DIAGRAM
Refer to DTC P2195 P2195.
INSPECTION PROCEDURE
HINT
Malfunctioning areas can be identified by performing the Control the Injection Volume function provided in the Active Test. The Control the Injection Volume function can help to determine whether the Air-Fuel Ratio (A/F) sensor, Heated Oxygen (HO2) sensor and other potential trouble areas are malfunctioning.
The following instructions describe how to conduct the Control the Injection Volume operation using the Techstream.
(a) Connect the Techstream to the DLC3.
(b) Put the engine in inspection mode Inspection Mode Procedure.
(c) Turn the Techstream ON.
(d) Warm up the engine at an engine speed of 2500 rpm for approximately 90 seconds.
(e) On the Techstream, enter the following menus: Powertrain / Engine and ECT / Active Test / Control the Injection Volume.
(f) Perform the Active Test operation with the engine idling (press the RIGHT or LEFT button to change the fuel injection volume).
(g) Monitor the output voltages of the A/F and HO2 sensors (AFS Voltage B1S1 and O2S B1S2 or AFS Voltage B2S1 and O2S B2S2) displayed on the Techstream.
HINT
- The Control the Injection Volume operation lowers the fuel injection volume by 12.5% or increases the injection volume by 25%.
- Each sensor reacts in accordance with increases and decreases in the fuel injection volume.
NOTICE:
The Air-Fuel Ratio (A/F) sensor has an output delay of a few seconds and the Heated Oxygen (HO2) sensor has a maximum output delay of approximately 20 seconds.
- Following the Control the Injection Volume procedure enables technicians to check and graph the voltage outputs of both the A/F and HO2 sensors.
- To display the graph, enter the following menus: Powertrain / Engine and ECT / Active Test / Control the Injection Volume / A/F Control System / AFS Voltage B1S1 and O2S B1S2 or AFS Voltage B2S1 and O2S B2S2.
HINT
- Read freeze frame data using the Techstream. Freeze frame data records the engine condition when malfunctions are detected. 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.
- A low A/F sensor voltage could be caused by a rich air-fuel mixture. Check for conditions that would cause the engine to run rich.
- A high A/F sensor voltage could be caused by a lean air-fuel mixture. Check for conditions that would cause the engine to run lean.
- 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.
PROCEDURE
1. CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO DTC P0171, P0172, P0174, P0175, P1170 OR P117B)
(a) Connect the Techstream to the DLC3.
(b) Turn the power switch on (IG) and turn the Techstream ON.
(c) Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.
(d) Read DTCs.
Result
HINT
If any DTCs other than P0171, P0172, P0174 or P0175, P1170 or P117B are output, troubleshoot those DTCs first.
B -- GO TO DTC CHART SFI System
A -- Continue to next step.
2. READ VALUE USING TECHSTREAM
(a) Connect the Techstream to the DLC3.
(b) Put the engine in inspection mode Inspection Mode Procedure.
(c) Turn the Techstream ON.
(d) Enter the following menus: Powertrain / Engine and ECT / Active Test / Control the Injection Way / Port.
(e) Read the value.
(1) Enter the following menus: Powertrain / Engine and ECT / Data List / A/F Control System / Short FT #1 and Long FT #1 and/or Short FT #2 and Long FT #2.
OK:
Short FT #1, #2 + Long FT #1, #2 = Between -19% and +19%
(f) Enter the following menus: Powertrain / Engine and ECT / Active Test / Control the Injection Way / Direct.
(g) Read the value.
(1) Enter the following menus: Powertrain / Engine and ECT / Data List / A/F Control System / Short FT #1 and Long FT #1 and/or Short FT #2 and Long FT #2.
OK:
Short FT #1, #2 + Long FT #1, #2 = Between -19% and +19%
Result
B -- CHECK FUEL PRESSURE SENSOR
C -- CHECK FUEL INJECTOR FOR PORT INJECTION
D -- CHECK PCV HOSE
A -- Continue to next step.
3. CHECK IF VEHICLE HAS RUN OUT OF FUEL IN PAST
(a) Has the vehicle run out of fuel in the past?
NO -- CHECK FOR INTERMITTENT PROBLEMS Check for Intermittent Problems
YES -- DTC CAUSED BY RUNNING OUT OF FUEL
4. CHECK PCV HOSE
OK:
PCV hose is connected correctly and is not damaged.
NG -- REPAIR OR REPLACE PCV HOSE Removal
OK -- Continue to next step.
5. CHECK AIR INDUCTION SYSTEM
(a) Check the air induction system for vacuum leakage Intake System.
OK:
No leakage from air induction system.
NG -- REPAIR OR REPLACE AIR INDUCTION SYSTEM Removal
OK -- Continue to next step.
6. PERFORM ACTIVE TEST USING TECHSTREAM
(a) Connect the Techstream to the DLC3.
(b) Put the engine in inspection mode Inspection Mode Procedure.
(c) Turn the Techstream ON.
(d) Warm up the engine at an engine speed of 2500 rpm for approximately 90 seconds.
(e) Enter the following menus: Powertrain / Engine and ECT / Active Test / Control the Injection Volume.
(f) Perform the Active Test operation with the engine idling (press the RIGHT or LEFT button to change the fuel injection volume).
(g) Monitor the output voltages of the A/F and HO2 sensors (AFS Voltage B1S1 and O2S B1S2 or AFS Voltage B2S1 and O2S B2S2) displayed on the Techstream.
HINT
- The Control the Injection Volume operation lowers the fuel injection volume by 12.5% or increases the injection volume by 25%.
- Each sensor reacts in accordance with increases and decreases in the fuel injection volume.
- If the sensor output voltage does not change (almost no reaction) while performing the Active Test, the sensor may be malfunctioning.
Result
Lean:
During Control the Injection Volume, the A/F sensor output voltage (AFS) is consistently more than 3.4 V, and the HO2 sensor output voltage (O2S) is consistently less than 0.4 V.
Rich:
During Control the Injection Volume, the AFS is consistently less than 3.1 V, and the O2S is consistently more than 0.55 V.
B -- INSPECT AIR FUEL RATIO SENSOR (HEATER RESISTANCE)
A -- Continue to next step.
7. READ VALUE USING TECHSTREAM (COOLANT TEMP)
(a) Connect the Techstream to the DLC3.
(b) Turn the Techstream ON.
(c) Enter the following menus: Powertrain / Engine and ECT / Data List / All Data / Coolant Temp.
(d) Read the Data List twice when the engine is both cold and warmed up.
Standard:
With cold engine
Same as ambient air temperature.
With warm engine
Between 75 and 95°C (167 and 203°F)
NG -- REPLACE ENGINE COOLANT TEMPERATURE SENSOR Removal
OK -- Continue to next step.
8. READ VALUE USING TECHSTREAM (MAF SENSOR 1, MAF SENSOR 2)
(a) Connect the Techstream to the DLC3.
(b) Turn the power switch on (IG).
(c) Turn the Techstream on.
(d) Put the engine in inspection mode Inspection Mode Procedure.
(e) Enter the following menus: Powertrain / Engine and ECT / Data List / All Data / MAF Sensor 1 and MAF Sensor 2, Coolant Temp.
(f) Allow the engine to idle until Coolant Temp reaches 75°C (167°F) or higher.
(g) Read MAF Sensor 1 and MAF Sensor 2 with the engine speed at 2500 rpm.
Standard:
Between 4.0 and 17.6 g/sec. (shift lever is in P position and engine is being raced)
NG -- CHECK HARNESS AND CONNECTOR
OK -- Continue to next step.
9. CHECK FOR EXHAUST GAS LEAK
(a) Check for exhaust gas leaks.
OK:
No gas leakage.
OK -- PERFORM CONFIRMATION DRIVING PATTERN
NG -- REPAIR OR REPLACE EXHAUST SYSTEM
10. INSPECT AIR FUEL RATIO SENSOR (HEATER RESISTANCE) P0031
NG -- REPLACE AIR FUEL RATIO SENSOR Removal
OK -- Continue to next step.
11. CHECK HARNESS AND CONNECTOR (A/F SENSOR - ECM)
(a) Disconnect the E47 and E48 A/F sensor connectors.
(b) Turn the power switch on (IG).
(c) Measure the voltage according to the value(s) in the table below.
Standard voltage:
(d) Turn the power switch off.
(e) Disconnect the E3 and E4 ECM connectors.
(f) Measure the resistance according to the value(s) in the table below.
Standard resistance (Check for open):
Standard resistance (Check for short):
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
12. REPLACE AIR FUEL RATIO SENSOR
(a) Replace the air fuel ratio sensor Removal.
NEXT -- Continue to next step.
13. PERFORM CONFIRMATION DRIVING PATTERN
(a) Refer to the confirmation driving pattern for P0171, P0172, P0174, P0175, P01170 and P0117B.
NEXT -- Continue to next step.
14. CHECK WHETHER DTC OUTPUT RECURS (DTC P0171, P0172, P0174, P0175, P1170 OR P117B)
(a) Enter the following menus: Powertrain / Engine and ECT / Trouble Codes / Pending.
(b) Read the Pending DTCs.
Result
B -- END
A -- Continue to next step.
15. CHECK FUEL PRESSURE (LOW PRESSURE)
(a) Check the fuel pressure Fuel System.
OK -- CHECK HARNESS AND CONNECTOR
NG -- CHECK FUEL PUMP OPERATION
16. CHECK FUEL PUMP OPERATION
(a) Check the fuel pump operation Fuel System.
NG -- REPLACE FUEL PUMP Removal
OK -- Continue to next step.
17. CHECK FOR FUEL LEAK (LOW PRESSURE SIDE)
(a) Check for fuel leaks (low pressure side).
OK:
No leakage
NG -- REPAIR OR REPLACE FUEL SYSTEM
OK -- CHECK AND REPLACE FUEL PUMP, PRESSURE REGULATOR, FUEL PIPE LINE AND FILTER
18. CHECK FUEL PRESSURE SENSOR
(a) Connect the Techstream to the DLC3.
(b) Put the engine in inspection mode Inspection Mode Procedure.
(c) Turn the Techstream ON.
(d) Enter the following menus: Powertrain / Engine and ECT / Data List / All Data / Fuel Press.
(e) While revving the engine, check that the fuel pressure fluctuates.
Standard:
Idling
3500 to 4500 kPa
2500 rpm (No load)
7000 to 9000 kPa
HINT
The A/C switch and all accessory switches should be OFF, the shift lever should be in the N or P position, and the engine should be fully warmed up.
NG -- CHECK MISFIRE COUNT
OK -- Continue to next step.
19. READ VALUE USING TECHSTREAM
(a) Connect the Techstream to the DLC3.
(b) Put the engine in inspection mode Inspection Mode Procedure.
(c) Turn the Techstream ON.
(d) Enter the following menus: Powertrain / Engine and ECT / Active Test / Control the Injection way / Direct.
HINT
The A/C switch and all accessory switches should be OFF, the shift lever should be in the N or P position, and the engine should be fully warmed up.
(e) Read the value.
(1) Enter the following menus: Powertrain / Engine and ECT / Data List / A/F Control System / Short FT #1, Long FT #1, Short FT #2, Long FT #2 and Fuel Pump Duty (D4).
Result
A -- REPLACE FUEL PRESSURE SENSOR Removal
B -- INSPECT FUEL RELIEF VALVE
C -- REPLACE ECM Removal
D -- Continue to next step.
20. READ VALUE USING TECHSTREAM
(a) Connect the Techstream to the DLC3.
(b) Put the engine in inspection mode Inspection Mode Procedure.
(c) Turn the Techstream ON.
(d) Enter the following menus: Powertrain / Engine and ECT / Active Test / Control the Injection way / Direct.
HINT
The A/C switch and all accessory switches should be OFF, the shift lever should be in the N or P position, and the engine should be fully warmed up.
(e) Read the value.
(1) Enter the following menus: Powertrain / Engine and ECT / Data List / A/F Control System / Short FT #1, Long FT #1, Short FT #2, Long FT #2 and Fuel Pump Duty (D4).
Result
B -- REPLACE FUEL INJECTOR FOR DIRECT INJECTION (for Bank 1) Removal
C -- REPLACE FUEL INJECTOR FOR DIRECT INJECTION (for Bank 2) Removal
D -- CHECK FOR INTERMITTENT PROBLEMS Check for Intermittent Problems
A -- REPLACE FUEL INJECTOR FOR DIRECT INJECTION (ALL CYLINDERS) Removal
21. CHECK MISFIRE COUNT
(a) Connect the Techstream to the DLC3.
(b) Put the engine in inspection mode Inspection Mode Procedure.
(c) Turn the Techstream ON.
(d) Enter the following menus: Powertrain / Engine and ECT / Active Test / Control the Injection Way / Direct.
(e) Allow the engine to idle.
(f) Monitor all of the misfire rate values that are displayed on the Techstream: Powertrain / Engine and ECT / Data List / Misfire / Cylinder #1 Misfire count to Cylinder #8 Misfire count.
If no misfire counts occur for any of the cylinders, perform the following procedure:
(1) Move the shift lever to the D position.
(2) Monitor all of the misfire count values that are displayed on the Techstream.
Result
B -- REPLACE FUEL INJECTOR ASSEMBLY (FOR DIRECT INJECTION) Removal
A -- Continue to next step.
22. INSPECT INJECTOR DRIVER (NO. 1 AND NO. 2)
(a) Turn the power switch off.
(b) Replace the No. 1 and No. 2 injector drivers with normal ones from another vehicle.
NOTICE:
Do not disconnect and reconnect the connectors with the power switch on (IG), as the injector driver (EDU) may be damaged.
(c) Connect the Techstream to the DLC3.
(d) Turn the power switch on (READY).
(e) Clear the DTCs Reading and Clearing Diagnostic Trouble Codes.
(f) Perform the driving test.
(g) Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.
(h) Read the DTCs.
Result
B -- REPLACE INJECTOR DRIVER (NO. 1 AND NO. 2) Removal
A -- Continue to next step.
23. INSPECT FUEL RELIEF VALVE
(a) Put the engine in inspection mode Inspection Mode Procedure.
(b) Warm up the engine.
(c) Connect the Techstream to the DLC3.
(d) Turn the Techstream ON.
(e) Enter the following menus: Powertrain / Engine and ECT / Data List / Primary / Fuel Press and Coolant Temp and Battery Voltage.
HINT
- Coolant Temp value is 50°C (122°F) or more
- Battery Voltage value is 10 V or more
- Fuel Press value is 2 MPa or more
(f) Turn the power switch off.
(g) Wait for 10 seconds.
(h) Put the engine in inspection mode.
(i) Enter the following menus: Powertrain / Engine and ECT / Data List / Primary / Fuel Press.
(j) After starting the engine, turn the power switch off within 45 seconds.
HINT
Before turning the power switch off, write down the Fuel Press value.
(k) Wait for 10 seconds. Then turn the power switch on (IG).
(l) Enter the following menus: Powertrain / Engine and ECT / Data List / Primary / Fuel Press.
(m) Check the fuel pressure.
OK:
Fuel pressure is stable.
NG -- REPLACE FUEL RELIEF VALVE Removal
A -- REPLACE FUEL PUMP FOR HIGH PRESSURE Removal
24. CHECK FUEL INJECTOR FOR PORT INJECTION
(a) Check the injection volume (whether fuel volume is high or low, and whether injection pattern is poor) Fuel Injector (for Port Injection).
NG -- REPLACE FUEL INJECTOR FOR PORT INJECTION Removal
OK -- REPLACE ECM Removal
25. CHECK HARNESS AND CONNECTOR
(a) Check the connection and terminal contact pressure of connectors and wire harnesses between the mass air flow meter and ECM Electronic Circuit Inspection Procedure.
HINT
Repair any problems.
NEXT -- Continue to next step.
26. PERFORM CONFIRMATION DRIVING PATTERN
(a) Refer to the confirmation driving pattern for P0171, P0172, P0174, P0175, P01170 and P0117B.
NEXT -- Continue to next step.
27. CHECK WHETHER DTC OUTPUT RECURS (DTC P0171, P0172, P0174, P0175, P1170 OR P117B)
(a) Enter the following menus: Powertrain / Engine and ECT / Trouble Codes / Pending.
(b) Read the pending DTCs.
Result:
B -- END
A -- Continue to next step.
28. CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER - ECM)
(a) Disconnect the E13 or E22 MAF meter connector.
(b) Disconnect the E1 ECM connector.
(c) Measure the resistance according to the value(s) in the table below.
Standard resistance (Check for open):
Standard resistance (Check for short):
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
29. REPLACE MASS AIR FLOW METER
(a) Replace the mass air flow meter Removal.
HINT
If the result of the inspection performed in step 8 indicated no problem, proceed to the next step without replacing the mass air flow meter.
NEXT -- Continue to next step.
30. PERFORM CONFIRMATION DRIVING PATTERN
(a) Refer to the confirmation driving pattern for P0171, P0172, P0174, P0175, P01170 and P0117B.
NEXT -- Continue to next step.
31. CHECK WHETHER DTC OUTPUT RECURS (DTC P0171, P0172, P0174, P0175, P1170 OR
P117B)
(a) Connect the Techstream to the DLC3.
(b) Turn the power switch on (IG).
(c) Turn the Techstream on.
(d) Enter the following menus: Powertrain / Engine and ECT / Trouble Codes / Pending.
(e) Read the pending DTCs.
Result
B -- END
A -- REPLACE ECM Removal