Infiniti QX4 (R50). Manual - part 146
21
CHECK HEATED OXYGEN SENSOR 1 (FRONT) (BANK 2) SIGNAL
With CONSULT-II
1. Stop engine.
2. Replace heated oxygen sensor 1 (front) (bank 2).
3. Start engine and warm it up to normal operating temperature.
4. Run engine at approx. 2,000 rpm for approx. 2 minutes under no-load.
5. See “HO2S1 MNTR (B2)” in “DATA MONITOR” mode.
6. Running engine at 2,000 rpm under no-load (engine is warmed up to normal operating temperature.), check that the
monitor fluctuates between “LEAN” and “RICH” more than 5 times during 10 seconds.
1 time: RICH
→
LEAN
→
RICH
2 times: RICH
→
LEAN
→
RICH
→
LEAN
→
RICH
Without CONSULT-II
1. Stop engine.
2. Replace heated oxygen sensor 1 (front) (bank 2).
3. Start engine and warm it up to normal operating temperature.
4. Run engine at approx. 2,000 rpm for approx. 2 minutes under no-load.
5. Set voltmeter probe between ECM terminal 62 and ground.
6. Make sure that the voltage fluctuates between 0 - 0.3V and 0.6 - 1.0V more than 5 times during 10 seconds at 2,000
rpm.
1 time: 0 - 0.3V
→
0.6 - 1.0V
→
0 - 0.3V
2 times: 0 - 0.3V
→
0.6 - 1.0V
→
0 - 0.3V
→
0.6 - 1.0V
→
0 - 0.3V
OK or NG
OK (With CONSULT-II)
©
GO TO 23.
OK (Without CONSULT-
II)
©
GO TO 24.
NG
©
GO TO 22.
22
DETECT MALFUNCTIONING PART
Check the following.
1. Check fuel pressure regulator. Refer to EC-40.
2. Check mass air flow sensor and its circuit. Refer to EC-150.
3. Check injector and its circuit. Refer to EC-616.
Clean or replace if necessary.
4. Check engine coolant temperature sensor and its circuit. Refer to EC-187.
5. Check ECM function by substituting another known-good ECM.
(ECM may be the cause of a problem, but this is rarely the case.)
©
GO TO 3.
GI
MA
EM
LC
FE
AT
TF
PD
AX
SU
BR
ST
RS
BT
HA
SC
EL
IDX
BASIC SERVICE PROCEDURE
Idle Speed/Ignition Timing/Idle Mixture Ratio Adjustment (Cont’d)
EC-51