DTC Logic
DTC DETECTION LOGIC
The ECM monitors the switching frequency ratio of air fuel ratio (A/F) sensor 1 and heated oxygen sensor 2.
A three way catalyst (manifold) with high oxygen storage capacity will indicate a low switching frequency of heated oxygen sensor 2.
As oxygen storage capacity decreases, the heated oxygen sensor 2 switching frequency will increase.
When the frequency ratio of air fuel ratio (A/F) sensor 1 and heated oxygen sensor 2 approaches a specified limit value, the three way catalyst (manifold) malfunction is diagnosed.
DTC No. | CONSULT screen terms (Trouble diagnosis content) | DTC detecting condition | Possible cause |
P0420 | TW CATALYST SYS-B1 (Catalyst system efficiency below threshold bank 1) |
|
|
DTC CONFIRMATION PROCEDURE
1.PRECONDITIONING
If DTC Confirmation Procedure has been previously conducted, always perform the following procedure before conducting the next test.
Will CONSULT be used? YES >> GO TO 2.
NO >> GO TO 6.
2.PERFORM DTC CONFIRMATION PROCEDURE-1
With CONSULT
TESTING CONDITION:
Do not hold engine speed for more than the specified minutes below.
If not, warm up engine and go to next step when “COOLANT TEMP/S” indication reaches to 70°C (158°F).
Which is displayed on CONSULT screen? CMPLT>> GO TO 5.
INCMP >> GO TO 3.
3.PERFORM DTC CONFIRMATION PROCEDURE-2
Does the indication change to “CMPLT”? YES >> GO TO 5.
NO >> GO TO 4.
4.PERFORM DTC CONFIRMATION PROCEDURE AGAIN
>> GO TO 2.
5.PERFORM DTC CONFIRMATION PROCEDURE-3
Check 1st trip DTC.
Is 1st trip DTC detected? YES >> Proceed to EC-285, "Diagnosis Procedure".
NO >> INSPECTION END
6.PERFORM COMPONENT FUNCTION CHECK
Perform component function check. Refer to EC-284, "Component Function Check".
NOTE:
Use component function check to check the overall function of the three way catalyst (manifold). During this check, a 1st trip DTC might not be confirmed.
Is the inspection result normal? YES >> INSPECTION END
NO >> Proceed to EC-285, "Diagnosis Procedure".
Component Function Check
1.PERFORM COMPONENT FUNCTION CHECK
Without CONSULT
Is the inspection result normal?
YES >> INSPECTION END
NO >> Proceed to EC-285, "Diagnosis Procedure".
Diagnosis Procedure
1.CHECK EXHAUST SYSTEM
Visually check exhaust tubes and muffler for dent.
Is the inspection result normal? YES >> GO TO 2.
NO >> Repair or replace error-detected parts.
2.CHECK EXHAUST GAS LEAK
Is exhaust gas leak detected? YES >> Repair or replace error-detected parts.
NO >> GO TO 3.
3.CHECK INTAKE AIR LEAK
Listen for an intake air leak after the mass air flow sensor.
Is intake air leak detected? YES >> Repair or replace error-detected parts.
NO >> GO TO 4.
4.CHECK IGNITION TIMING AND IDLE SPEED
Check the following items.
Is the inspection result normal? YES >> GO TO 5.
NO >> Perform “BASIC INSPECTION”. Refer to EC-131, "Work Procedure".
5.CHECK FUEL INJECTOR
Check the fuel injector. Refer to EC-450, "Component Function Check".
Is the inspection result normal? YES >> GO TO 6.
NO >> Perform EC-450, "Diagnosis Procedure".
6.CHECK FUNCTION OF IGNITION COIL-1
CAUTION:
Do the following procedure in the place where ventilation is good without the combustible.
NOTE:
Do not use CONSULT to release fuel pressure, or fuel pressure applies again during the following procedure.
Spark should be generated.
CAUTION:
NOTE:
When the gap is less than 13 mm (0.52 in), the spark might be generated even if the coil is malfunctioning.
Is the inspection result normal? YES >> GO TO 10.
NO >> GO TO 7.
7.CHECK FUNCTION OF IGNITION COIL-2
Spark should be generated
Is the inspection result normal? YES >> GO TO 8.
NO >> Check ignition coil, power transistor and their circuits. Refer to EC-456, "Diagnosis Procedure".
8.CHECK SPARK PLUG
Check the initial spark plug for fouling, etc. Refer to EM-13, "Inspection".
Is the inspection result normal? YES >> Replace spark plug(s) with standard type one(s). For spark plug type, refer to EM-118, "Spark Plug".
NO >> 1. Repair or clean spark plug. Refer to EM-45, "Removal and Installation".
2. GO TO 9.
9.CHECK FUNCTION OF IGNITION COIL-3
Spark should be generated.
Is the inspection result normal? YES >> INSPECTION END
NO >> Replace spark plug(s) with standard type one(s). For spark plug type, refer to EM-118, "Spark Plug".
10.CHECK FUEL INJECTOR
Keep fuel hose and all fuel injectors connected to fuel tube.
Does fuel drip from fuel injector? YES >> GO TO 11.
NO >> Replace the fuel injector(s) from which fuel is dripping. Refer to EM-40, "Removal and Installation".
11.CHECK INTERMITTENT INCIDENT
Check intermittent incident. Refer to GI-39, "Intermittent Incident".
Is the trouble fixed? YES >> INSPECTION END
NO >> Replace three way catalyst assembly. Refer to EX-5, "Exploded View".
Service Notice and Precautions for Road Wheel
Genuine NISSAN aluminum wheel is designed for each type of vehicle. Use
it on the specified vehicle only.
Use Genuine NISSAN parts for the road wheels, valve caps and wheel nuts.
Always use them after adjusting the wheel balance. For the balance
weights, use Genuine NISSAN aluminum
wh ...
NISSAN Intelligent Key® battery discharge
If the battery of the NISSAN Intelligent Key® is
discharged, or environmental conditions interfere
with the Intelligent Key operation, start the engine
according to the following procedure:
Place the shift lever in the P (Park) position.
Firmly apply the foot brake.
Touch the ignitio ...
Front fog lamp
Removal and Installation
FOG LAMP
Removal
Position the fender protector aside. Refer to EXT-28, "FENDER PROTECTOR
: Removal and Installation
- Front Fender Protector".
Disconnect the harness connector from the front fog lamp.
Remove the screws and the front fog lamp.
Inst ...