Nissan Titan. Manual — part 235
P0171, P0174 FUEL INJECTION SYSTEM FUNCTION
EC-241
< DTC/CIRCUIT DIAGNOSIS >
[VK56DE]
C
D
E
F
G
H
I
J
K
L
M
A
EC
N
P
O
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
engine does not start, check exhaust and intake air leak visually.
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 harness connector.
4. Restart engine and let it idle for at least 5 seconds.
5. Stop engine and reconnect mass air flow sensor harness con-
nector.
6. Select Service $03 with GST. Make sure DTC P0102 is
detected.
7. Select Service $04 with GST and erase the DTC P0102.
8. Start engine again and let it idle for at least 10 minutes.
9. Select Service $07 with GST. The 1st trip DTC P0171 or P0174
should be detected at this stage, if a malfunction exists. If so, go
.
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 10 min-
utes. 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.
10. If it is difficult to start engine at step 8, the fuel injection system has a malfunction.
11. Crank engine while depressing accelerator pedal. If engine starts, go to
If engine does not start, check exhaust and intake air leak visually.
Diagnosis Procedure
INFOID:0000000009886651
1.
CHECK EXHAUST GAS LEAK
1. Start engine and run it at idle.
Engine coolant temperature (T)
condition
When 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).
BBIA0368E
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)
condition
When 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).
EC-242
< DTC/CIRCUIT DIAGNOSIS >
[VK56DE]
P0171, P0174 FUEL INJECTION SYSTEM FUNCTION
2. Listen for an exhaust gas leak before three way catalyst (manifold).
OK or NG
OK
>> GO TO 2.
NG
>> Repair or replace.
2.
CHECK FOR INTAKE AIR LEAK
1. Listen for an intake air leak after the mass air flow sensor.
2. Check PCV hose connection.
OK or NG
OK
>> GO TO 3.
NG
>> Repair or replace.
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.
PBIB1216E
A/F sensor 1 terminal
ECM terminal
Bank 1
1
35
2
56
Bank 2
1
16
2
75
Continuity should exist.
Bank 1
Bank 2
A/F sensor 1 terminal
ECM terminal
A/F sensor 1 terminal
ECM terminal
1
35
1
16
2
56
2
75
Continuity should not exist.
BBIA0376E
P0171, P0174 FUEL INJECTION SYSTEM FUNCTION
EC-243
< DTC/CIRCUIT DIAGNOSIS >
[VK56DE]
C
D
E
F
G
H
I
J
K
L
M
A
EC
N
P
O
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
2. Install fuel pressure gauge kit [SST (J-44321)] and check fuel pressure. Refer to
.
OK or NG
OK
>> GO TO 6.
NG
>> GO TO 5.
5.
DETECT MALFUNCTIONING PART
Check the following.
• Fuel pump and circuit (Refer to
.)
• <Flexible Fuel Vehicle>
FPCM and circuit (Refer to
.)
• Fuel pressure regulator (Refer to
• Fuel lines
• Fuel filter for clogging
>> Repair or replace.
6.
CHECK MASS AIR FLOW SENSOR
With CONSULT
1. Install all removed parts.
2. Check “MASS AIR FLOW” in “DATA MONITOR” mode with CONSULT.
With GST
1. Install all removed parts.
2. 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
grounds. Refer to
.
7.
CHECK FUNCTION OF FUEL INJECTOR
With CONSULT
1. Start engine.
2. Perform “POWER BALANCE” in “ACTIVE TEST” mode with CONSULT.
3. Make sure that each circuit produces a momentary engine speed drop.
Without CONSULT
1. Start engine.
At idling: Approximately 350 kPa (3.57 kg/cm
2
, 51 psi)
3.0 - 9.0 g/s
: at idling
9.0 - 28.0 g/s
: at 2,500 rpm
3.0 - 9.0 g/s
: at idling
97.0 - 28.0 g/s
: at 2,500 rpm
EC-244
< DTC/CIRCUIT DIAGNOSIS >
[VK56DE]
P0171, P0174 FUEL INJECTION SYSTEM FUNCTION
2. Listen to each fuel injector operating sound.
OK or NG
OK
>> GO TO 8.
NG
>> Perform trouble diagnosis for FUEL INJECTOR, refer to
.
8.
CHECK FUEL INJECTOR
1. Confirm that the engine is cooled down and there are no fire hazards near the vehicle.
2. Turn ignition switch OFF.
3. Disconnect all fuel injector harness connectors.
4. Remove fuel injector gallery assembly. Refer to
EM-43, "Removal and Installation"
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
GI-39, "How to Check Terminal"
and
GI-42, "Intermittent Incident"
>> INSPECTION END
Clicking noise should be heard.
PBIB1986E
Fuel should be sprayed evenly for each fuel injector.
PBIB1726E
Нет комментариевНе стесняйтесь поделиться с нами вашим ценным мнением.
Текст