ITB19-007

Classification:
Reference:
Date:
EC19-016
ITB19-007
March 5, 2019
INFINITI; P0171 AND P0174 SERVICE INFORMATION
APPLIED VEHICLES:
2017-2019 Q50 (V37)
2017-2019 Q60 (V37)
2017-2019 QX60 (L50)
2017-2019 QX80 (Z62)
SERVICE INFORMATION
Diagnosis for DTCs P0171 (FUEL SYS LEAN B1) and P0174 (FUEL SYS LEAN B2) have been revised for
the APPLIED VEHICLES listed above. When performing diagnosis for either of these DTCs, start by using the
SERVICE PROCEDURE section of this bulletin.
NOTE: The related Electronic Service Manuals (ESM) will be revised in the future to include these diagnostic
steps.
Infiniti Bulletins are intended for use by qualified technicians, not 'do-it-yourselfers'. Qualified technicians are properly trained
individuals who have the equipment, tools, safety instruction, and know-how to do a job properly and safely. NOTE: If you
believe that a described condition may apply to a particular vehicle, DO NOT assume that it does. See your Infiniti retailer to
determine if this applies to your vehicle.
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SERVICE PROCEDURE
FLOW CHART
DTC P0171 and/or
P0174 detected
Check A/F sensor function according to
DTC Confirmation for P2096/P2097/P2098/P2099
Go to the next page,
perform DTC Confirmation Procedure,
and then go to the box below
Yes
Is DTC P2096, P2097, P2098, or P2099 detected?
No
Do NOT replace
the A/F sensor
Replace the A/F sensor
END
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Continue diagnosis
in the ESM
for P0171 / P0174
excluding A/F sensor
ITB19-007
DTC Confirmation
Preconditioning
If DTC Confirmation has been previously conducted, always perform the following before conducting the next
test:
1. Turn the ignition switch OFF and wait at least 10 seconds.
2. Turn the ignition switch ON.
3. Turn the ignition switch OFF and wait at least 10 seconds.
Testing Condition
Confirm battery voltage is 11 volts or more at idle before performing DTC Confirmation.
Perform DTC Confirmation
4. Clear the mixture ratio self-learning value:
a. Connect the CONSULT PC and plus VI to the vehicle.
b. Open CONSULT-III plus (C-III plus).
c. Start the engine and warm it up to normal operating temperature.
d. Go to WORK SUPPORT, and then select SELF-LEARNING CONT.
e. Clear mixture ratio self-learning value by selecting CLEAR.
5.
6.
7.
8.
Turn the ignition switch OFF and wait at least 10 seconds.
Turn the ignition switch ON.
Turn the ignition switch OFF and wait at least 10 seconds.
Start the engine and keep the engine speed between 3,500 and 4,000 RPM for one (1) minute under
no load.
9. Let the engine idle for 1 minute.
10. Keep the engine speed between 2,500 and 3,000 RPM for 20 minutes.
11. Check for 1st trip DTC:

If DTC P2096, P2097, P2098, or P2099 is stored, replace the corresponding A/F sensor.

If no DTCs are stored, continue with the diagnosis in the ESM for P0171 / P0174 excluding A/F
sensor.
AMENDMENT HISTORY
PUBLISHED DATE
March 5, 2019
REFERENCE
ITB19-007
DESCRIPTION
Original bulletin published
3/3
ITB19-007