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Infiniti Q45 (FY33). Manual - part 129

SEF957D

SEC042C

SEF217U

Set on board diagnostic system of ECM to Diagnostic Test Mode II
(Heated oxygen sensor 1 monitor).*

Check heated oxygen sensor 1 (front) (B1) signal.

1) See “HO2S1 MNTR (B1) and (B2) (left

and right sides)” in “Data monitor” mode.

2) Maintaining engine at 2,000 rpm under

no-load (engine is warmed up
sufficiently.), check that the monitor fluc-
tuates between “LEAN” and “RICH”
more than 5 times during 10 seconds.
1 cycle: RICH

→

LEAN

→

RICH

2 cycles: RICH

→

LEAN

→

RICH

→

LEAN

→

RICH

Make sure that malfunction indicator lamp
goes on and off more than 5 times during
10 seconds at 2,000 rpm.

Monitor does not fluc-
tuate. Malfunction
indicator lamp does
not blink.

Less than 5 times

Replace heated oxygen sensor 1 (front) (B1).

Check heated oxygen sensor 1 (front) (B1) signal.

1) See “HO2S1 MNTR (B1) and (B2) (right

and left sides)” in “Data monitor” mode.

2) Maintaining engine at 2,000 rpm under

no-load (engine is warmed up
sufficiently.), check that the monitor fluc-
tuates between “LEAN” and “RICH”
more than 5 times during 10 seconds.
1 cycle: RICH

→

LEAN

→

RICH

2 cycles: RICH

→

LEAN

→

RICH

→

LEAN

→

RICH

Make sure that malfunction indicator lamp
goes on and off more than 5 times during
10 seconds at 2,000 rpm.

*: If the battery is weak, heated oxygen sensor 1 monitor may not function

properly. Use this function after fully charging battery.

IDX

BASIC SERVICE PROCEDURE

Idle Speed/Ignition Timing/Idle Mixture Ratio
Adjustment (Cont’d)

EC-45

SEC042C

SEF217U

Check heated oxygen sensor 1 (front) (B1) signal.

1) See “HO2S1 MNTR (B1) and (B2) (left

and right sides)” in “Data monitor” mode.

2) Maintaining engine at 2,000 rpm under

no-load (engine is warmed up
sufficiently.), check that the monitor fluc-
tuates between “LEAN” and “RICH”
more than 5 times during 10 seconds.
1 cycle: RICH

→

LEAN

→

RICH

2 cycles: RICH

→

LEAN

→

RICH

→

LEAN

→

RICH

Make sure that malfunction indicator lamp
goes on and off more than 5 times during
10 seconds at 2,000 rpm.

Monitor does not fluc-
tuate.
Malfunction indicator
lamp does not blink.

Less than 5 times

END

Replace heated oxygen sensor 1 (front) (B2).

Check heated oxygen sensor 1 (front) (B2) signal.

1) See “HO2S1 MNTR (B1) and (B2) (left

and right sides)” in “Data monitor” mode.

2) Maintaining engine at 2,000 rpm under

no-load (engine is warmed up
sufficiently.), check that the monitor fluc-
tuates between “LEAN” and “RICH”
more than 5 times during 10 seconds.
1 cycle: RICH

→

LEAN

→

RICH

2 cycles: RICH

→

LEAN

→

RICH

→

LEAN

→

RICH

Make sure that malfunction indicator lamp
goes on and off more than 5 times during
10 seconds at 2,000 rpm.

END

BASIC SERVICE PROCEDURE

Idle Speed/Ignition Timing/Idle Mixture Ratio
Adjustment (Cont’d)

EC-46

SEF213UA

SEF214UA

Check heated oxygen sensor 1 (front) (B2) harness:
1) Turn off engine and disconnect battery ground cable
2) Disconnect ECM harness connector from ECM.
3) Disconnect heated oxygen sensor 1 (front) (B2) harness connec-

tor.

4) Check for continuity between terminal No. 82 of ECM harness

connector and harness connector for heated oxygen sensor 1
(front).

-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

Continuity exists. ........................................................................OK
Continuity does not exist. ..........................................................NG

Repair or replace ECM harness.

Connect ECM harness connector to ECM.

Check heated oxygen sensor 1 (front) (B1) harness:
1) Turn off engine and disconnect battery ground cable
2) Disconnect ECM harness connector from ECM.
3) Disconnect heated oxygen sensor 1 (front) (B1) harness connec-

tor.

4) Check for continuity between terminal No. 83 of ECM harness

connector and harness connector for heated oxygen sensor 1
(front).

Continuity exists. ........................................................................OK
Continuity does not exist. ..........................................................NG

Repair or replace ECM harness.

Connect ECM harness connector to ECM.

IDX

BASIC SERVICE PROCEDURE

Idle Speed/Ignition Timing/Idle Mixture Ratio
Adjustment (Cont’d)

EC-47

SEF760X

SEF858QA

SEF246F

SEF248F

1) Select “ENG COOLANT TEMP” in “ACTIVE TEST” mode.
2) Set “COOLANT TEMP” to 5°C (41°F) by touching “DWN”

and “Qd”.

-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- OR --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

1) Disconnect engine coolant temperature sensor harness

connector.

2) Connect a resistor (4.4 k

Ω

) between terminals of engine

coolant temperature sensor harness connector.

Start engine and warm it up until engine coolant temperature indica-
tor points to the middle of gauge.

Race engine two or three times under no-load, then run engine at
idle speed.

Check “CO” %.

Idle CO: 0.4 - 9.4% with engine running smoothly

After checking CO%,
1) Disconnect the resistor from terminals of engine coolant tempera-

ture sensor.

2) Connect engine coolant temperature sensor harness connector to

engine coolant temperature sensor.

Connect heated oxygen sensor 1 (front) harness connectors to
heated oxygen sensors 1 (front).

Check fuel pressure regulator.

Check mass air flow sensor.

Check injector.
Clean or replace if necessary.

Check engine coolant temperature sensor.

Check ECM function* by substituting another known-good ECM.

*: ECM may be the cause of a problem, but this is rarely the case.

Note: If a vehicle contains a part which is operating outside of design specifications with no MIL

illumination, the part shall not be replaced prior to emission testing unless it is determined that
the part has been tampered with or abused in such a way that the diagnostic system cannot
reasonably be expected to detect the resulting malfunction.

BASIC SERVICE PROCEDURE

Idle Speed/Ignition Timing/Idle Mixture Ratio
Adjustment (Cont’d)

EC-48

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