NISSAN 350Z 2007 Z33 Engine Control Workshop Manual

DTC P0171, P0174 FUEL INJECTION SYSTEM FUNCTION
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Revision: 2006 November2007 350Z
3. CHECK A/F SENSOR 1 INPUT SIGNAL CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect corresponding A/F sensor 1 harness connector.
3. Disconnect ECM harness connector.
4. Check harness continuity between the following terminals.
Refer to Wiring Diagram.
5. Check harness continuity between the following terminals and ground.
Refer to Wiring Diagram.
6. Also check harness for short to power.
OK or NG
OK >> GO TO 4.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
4. CHECK FUEL PRESSURE
1. Release fuel pressure to zero. Refer to EC-79, "
FUEL PRESSURE RELEASE" .
2. Install fuel pressure gauge and check fuel pressure. Refer to EC-80, "
FUEL PRESSURE CHECK" .
OK or NG
OK >> GO TO 6.
NG >> GO TO 5.
1. A/F sensor 1 harness connector
(bank 1)2. A/Fsensor 1 harness connector
(bank 2)
:Vehicle front
A/F sensor 1 terminal ECM terminal
Bank 1157
261
Bank 2165
266
Continuity should exist.
Bank 1 Bank 2
A/F sensor 1 terminal ECM terminal A/F sensor 1 terminal ECM terminal
157165
261266
Continuity should not exist.
PBIB3516E
At idling: Approximately 350 kPa (3.57 kg/cm2 , 51 psi)

EC-332
DTC P0171, P0174 FUEL INJECTION SYSTEM FUNCTION
Revision: 2006 November2007 350Z
5. DETECT MALFUNCTIONING PART
Check the following.

Fuel pump and circuit (Refer to EC-691, "FUEL PUMP" .)

Fuel pressure regulator (Refer to EC-80, "FUEL PRESSURE CHECK" )

Fuel lines (Refer to FL-3, "Checking Fuel Lines" .)

Fuel filter for clogging
>> Repair or replace.
6. CHECK MASS AIR FLOW SENSOR
With CONSULT-III
1. Install all removed parts.
2. Start engine and warm it up normal temperature.
3. Check “MASS AIR FLOW” in “DATA MONITOR” mode with CONSULT-III.
With GST
1. Install all removed parts.
2. Start engine and warm it up normal temperature.
3. Check mass air flow sensor signal in Service $01 with GST.
OK or NG
OK >> GO TO 7.
NG >> Check connectors for rusted terminals or loose connections in the mass air flow sensor circuit or
ground. Refer to EC-197, "
DTC P0101, P010B MAF SENSOR" .
7. CHECK FUNCTION OF FUEL INJECTOR
With CONSULT-III
1. Start engine.
2. Perform “POWER BALANCE” in “ACTIVE TEST” mode with CONSULT-III.
3. Make sure that each circuit produces a momentary engine speed drop.
Without CONSULT-III
1. Start engine and let it idle.
2. Listen to each fuel injector operating sound.
OK or NG
OK >> GO TO 8.
NG >> Perform trouble diagnosis for FUEL INJECTOR, refer to
EC-686, "
FUEL INJECTOR" . 2.0 - 6.0 g·m/sec: at idling
7.0 - 20.0 g·m/sec: at 2,500 rpm
2.0 - 6.0 g·m/sec: at idling
7.0 - 20.0 g·m/sec: at 2,500 rpm
Clickng sound should be heard.
PBIB3332E

DTC P0171, P0174 FUEL INJECTION SYSTEM FUNCTION
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Revision: 2006 November2007 350Z
8. CHECK FUEL INJECTOR
1. Turn ignition switch OFF.
2. Confirm that the engine is cooled down and there are no fire hazards near the vehicle.
3. Disconnect all fuel injector harness connectors.
4. Remove fuel injector gallery assembly. Refer to EM-34, "
FUEL INJECTOR AND FUEL TUBE" .
Keep fuel hose and all fuel injectors connected to fuel injector gallery.
5. For DTC P0171, reconnect fuel injector harness connectors on bank 1.
For DTC P0174, reconnect fuel injector harness connectors on bank 2.
6. Disconnect all ignition coil harness connectors.
7. Prepare pans or saucers under each fuel injector.
8. Crank engine for about 3 seconds.
For DTC P0171, make sure that fuel sprays out from fuel injec-
tors on bank 1.
For DTC P0174, make sure that fuel sprays out from fuel injec-
tors on bank 2.
OK or NG
OK >> GO TO 9.
NG >> Replace fuel injectors from which fuel does not spray
out. Always replace O-ring with new ones.
9. CHECK INTERMITTENT INCIDENT
Refer to EC-141, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>>INSPECTION END Fuel should be sprayed evenly for each fuel injector.
PBIB1726E

EC-334
DTC P0172, P0175 FUEL INJECTION SYSTEM FUNCTION
Revision: 2006 November2007 350Z
DTC P0172, P0175 FUEL INJECTION SYSTEM FUNCTIONPFP:16600
On Board Diagnosis LogicNBS00074
With the Air/Fuel Mixture Ratio Self-Learning Control, the actual mixture ratio can be brought closely to the
theoretical mixture ratio based on the mixture ratio feedback signal from the air fuel ratio (A/F) sensors 1. The
ECM calculates the necessary compensation to correct the offset between the actual and the theoretical
ratios.
In case the amount of the compensation value is extremely large (The actual mixture ratio is too rich.), the
ECM judges the condition as the fuel injection system malfunction and lights up the MIL (2 trip detection logic).
DTC Confirmation ProcedureNBS00075
NOTE:
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
WITH CONSULT-III
1. Start engine and warm it up to normal operating temperature.
2. Turn ignition switch OFF and wait at least 10 seconds.
3. Turn ignition switch ON and select “SELF-LEARNING CONT” in “WORK SUPPORT” mode with CON-
SULT-III.
4. Clear the self-learning control coefficient by touching “CLEAR”.
5. Start engine again and let it idle for at least 10 minutes.
6. Check 1st trip DTC.
The 1st trip DTC P0172, P0175 should be detected at this stage, if a malfunction exists.
If so, go to EC-340, "
Diagnostic Procedure" .
NOTE:
If 1st trip DTC is not detected during above procedure, performing the following procedure is advised.
a. Turn ignition switch OFF and wait at least 10 seconds.
b. Start engine and select “DATA MONITOR” mode with CONSULT-III.
c. Drive the vehicle under the similar conditions to (1st trip) Freeze Frame Data for a certain time.
Refer to the table below.
Hold the accelerator pedal as steady as possible.
The similar conditions to (1st trip) Freeze Frame Data means the vehicle operation that the following con-
ditions should be satisfied at the same time.
7. If it is difficult to start engine at step 6, the fuel injection system has a malfunction, too.
8. Crank engine while depressing accelerator pedal.
If engine starts, go to EC-340, "
Diagnostic Procedure" . If engine does not start, remove ignition plugs and
check for fouling, etc.
Sensor Input signal to ECM ECM function Actuator
Air fuel ratio (A/F) sensor 1Density of oxygen in exhaust gas
(Mixture ratio feedback signal)Fuel injection control Fuel injector
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0172
0172
(Bank 1)
Fuel injection system too
rich

Fuel injection system does not operate properly.

The amount of mixture ratio compensation is too
large. (The mixture ratio is too rich.)

Air fuel ratio (A/F) sensor 1

Fuel injector

Exhaust gas leaks

Incorrect fuel pressure

Mass air flow sensor P0175
0175
(Bank 2)
Engine speed Engine speed in the freeze frame data ± 400 rpm
Vehicle speed Vehicle speed in the freeze frame data ± 10 km/h (6 MPH)
Engine coolant temperature
(T) conditionWhen the freeze frame data shows lower than 70 °C (158 °F),
T should be lower than 70 °C (158 °F).
When the freeze frame data shows higher than or equal to 70 °C (158 °F),
T should be higher than or equal to 70 °C (158 °F).

DTC P0172, P0175 FUEL INJECTION SYSTEM FUNCTION
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Revision: 2006 November2007 350Z
WITH GST
1. Start engine and warm it up to normal operating temperature.
2. Turn ignition switch OFF and wait at least 10 seconds.
3. Disconnect mass air flow sensor (bank 1) harness connector. Then restart and run engine for at least 5
seconds at idle speed.
4. Stop engine and reconnect mass air flow sensor (bank 1) harness connector.
5. Select Service $03 with GST. Make sure DTC P0102 is detected.
6. Select Service $04 with GST and erase the DTC P0102.
7. Start engine again and let it idle for at least 10 minutes.
8. Select Service $07 with GST. The 1st trip DTC P0172 or P0175 should be detected at this stage, if a mal-
function exists. If so, go to EC-340, "
Diagnostic Procedure" .
NOTE:
If 1st trip DTC is not detected during above procedure, performing the following procedure is advised.
a. Turn ignition switch OFF and wait at least 10 seconds.
b. Start engine and drive the vehicle under the similar conditions to (1st trip) Freeze Frame Data for a certain
time. Refer to the table below.
Hold the accelerator pedal as steady as possible.
The similar conditions to (1st trip) Freeze Frame Data means the vehicle operation that the following con-
ditions should be satisfied at the same time.
9. If it is difficult to start engine at step 7, the fuel injection system has a malfunction.
10. Crank engine while depressing accelerator pedal.
If engine starts, go to EC-340, "
Diagnostic Procedure" . If engine does not start, remove ignition plugs and
check for fouling, etc.
1. Mass air flow sensor (with intake air
temperature sensor) (bank 1)2. Mass air flow sensor (with intake air
temperature sensor) (bank 2)
Engine speed Engine speed in the freeze frame data ± 400 rpm
Vehicle speed Vehicle speed in the freeze frame data ± 10 km/h (6 MPH)
Engine coolant temperature
(T) conditionWhen the freeze frame data shows lower than 70 °C (158 °F),
T should be lower than 70 °C (158 °F).
When the freeze frame data shows higher than or equal to 70 °C (158 °F),
T should be higher than or equal to 70 °C (158 °F).
PBIB3501E

EC-336
DTC P0172, P0175 FUEL INJECTION SYSTEM FUNCTION
Revision: 2006 November2007 350Z
Wiring DiagramNBS006UY
BANK 1
TBWT1636E

DTC P0172, P0175 FUEL INJECTION SYSTEM FUNCTION
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Specification data are reference values and are measured between each terminal and ground.
Pulse signal is measured by CONSULT-III.
CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.
TER-
MINAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
1W/RA/F sensor 1 heater
(bank 1)[Engine is running]

Warm-up condition

Idle speed
(More than 140 seconds after starting
engine)2.9 - 8.8V
57 L A/F sensor 1 (bank 1)[Ignition switch: ON]2.2V
61 R A/F sensor 1 (bank 1)[Ignition switch: ON]

Warm-up condition

Engine speed: 2,000 rpm1.8V
Output voltage varies with air
fuel ratio.
81
86
89R/B
W/B
G/YFuel injector No. 3
Fuel injector No. 5
Fuel injector No. 1 [Engine is running]

Warm-up condition

Idle speed
NOTE:
The pulse cycle changes depending on rpm at
idle.BATTERY VOLTAGE
(11 - 14V)
[Engine is running]

Warm-up condition

Engine speed: 2,000 rpmBATTERY VOLTAGE
(11 - 14V)
PBIB3538E
PBIB3555E
PBIB3556E

EC-338
DTC P0172, P0175 FUEL INJECTION SYSTEM FUNCTION
Revision: 2006 November2007 350Z
BANK 2
TBWT1638E

DTC P0172, P0175 FUEL INJECTION SYSTEM FUNCTION
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Revision: 2006 November2007 350Z
Specification data are reference values and are measured between each terminal and ground.
Pulse signal is measured by CONSULT-III.
CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.
TER-
MINAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
5GY/LA/F sensor 1 heater
(bank 2)[Engine is running]

Warm-up condition

Idle speed
(More than 140 seconds after starting
engine)2.9 - 8.8
65 PU A/F sensor 1 (bank 2)[Ignition switch: ON]2.2V
66 LG A/F sensor 1 (bank 2)[Ignition switch: ON]

Warm-up condition

Engine speed: 2,000 rpm1.8V
Output voltage varies with air
fuel ratio.
82
85
90L/R
BR
Y/RFuel injector No. 6
Fuel injector No. 2
Fuel injector No. 4[Engine is running]

Warm-up condition

Idle speed
NOTE:
The pulse cycle changes depending on rpm at
idle.BATTERY VOLTAGE
(11 - 14V)
[Engine is running]

Warm-up condition

Engine speed: 2,000 rpmBATTERY VOLTAGE
(11 - 14V)
PBIB3538E
PBIB3555E
PBIB3556E

EC-340
DTC P0172, P0175 FUEL INJECTION SYSTEM FUNCTION
Revision: 2006 November2007 350Z
Diagnostic ProcedureNBS00077
1. CHECK EXHAUST GAS LEAK
1. Start engine and run it at idle.
2. Listen for an exhaust gas leak before three way catalyst 1.
OK or NG
OK >> GO TO 2.
NG >> Repair or replace.
2. CHECK FOR INTAKE AIR LEAK
Listen for an intake air leak after the mass air flow sensor.
OK or NG
OK >> GO TO 3.
NG >> Repair or replace.
PBIB1922E