2001 INFINITI QX4 high beam

4 CHECK REAR WINDOW DEFOGGER INPUT SIGNAL CIRCUIT FOR OPEN OR SHORT
1. Stop engine.
2. Disconnect ECM harness connector.
3. Disconnect rear window defogger relay.
4. Check harness continuity between ECM terminal 52 and rear window defogger relay terminals 7.
SEF031Z
5. Also check harness for short to ground and short to power.
OK or NG
OK©GO TO 6.
NG©GO TO 5.
5 DETECT MALFUNCTIONING PART
Check the following.
IHarness connectors E1, M1
IHarness connectors M33, F22
IDiode M37
IHarness for open and short between ECM and rear window defigger relay
©Repair open circuit or short to ground or short to power in harness or connectors.
6 CHECK INTERMITTENT INCIDENT
Perform ªTROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENTº, EC-140.
©INSPECTION END
7 CHECK HEADLAMP FUNCTION
1. Start engine.
2. Turn the lighting switch ªONº at 1st position with high beam.
3. Check that headlamps are illuminated.
OK or NG
OK©GO TO 8.
NG©Refer to EL-60, ªHEADLAMP (FOR USA)º or EL-123, ªHEADLAMP (FOR CANADA) Ð
DAYTIME LIGHT SYSTEMº.
ELECTRICAL LOAD SIGNAL
Diagnostic Procedure (Cont'd)
EC-646

When the ignition switch is in the ACC or ON position, power is supplied
Ito auto light control unit terminal 2
Ithrough 10A fuse [No. 9, located in the fuse block (J/B)]
Ground is supplied
Ito headlamp battery saver control unit terminals 4 and 11
Ithrough body grounds M77 and M111, and M4,M66 and M147
Ito auto light control unit terminal 5
Ithrough body grounds M4, M66 and M147.
Power Supply to Low Beam and High BeamNBEL0188S0101When lighting switch is in 2ND or PASS position, ground is supplied
Ito headlamp relay (LH and RH) terminal 2 from headlamp battery saver control unit terminals 2 and 8
Ithrough headlamp battery saver control unit terminals 3 and 9,
Ifrom lighting switch terminal 12.
Headlamp relays (LH and RH) are energized and then power is supplied to headlamps (LH and RH).
LOW BEAM OPERATIONNBEL0188S02When the lighting switch is turned to the 2ND position and placed in LOW (ªBº) position, power is supplied
Ifrom terminal 7 of each headlamp relay
Ito terminal 3 of each headlamp
Ground is supplied
Ito terminal 4 of each headlamp
Ithrough body grounds E13 and E41.
With power and ground supplied, the headlamp(s) will illuminate.
HIGH BEAM OPERATION/FLASH-TO-PASS OPERATIONNBEL0188S03When the lighting switch is turned to the 2ND position and placed in HIGH (ªAº) position or PASS (ªCº) position,
power is supplied
Ifrom terminal 5 of headlamp LH relay
Ito terminal 1 of headlamp LH, and
Ito combination meter terminal 26 for the HIGH BEAM indicator
Ifrom terminal 5 of headlamp RH relay
Ito terminal 1 of headlamp RH.
Ground is supplied
Ito headlamp LH terminal 2
Ito combination meter terminal 27 for the HIGH BEAM indicator
Ithrough lighting switch terminals 6 and 5
Ithrough body grounds E13 and E41, and
Ito headlamp RH terminal 2
Ithrough lighting switch terminals 9 and 8
Ithrough body grounds E13 and E41.
With power and ground supplied, the high beams and the high beam indicator illuminate.
BATTERY SAVER CONTROLNBEL0188S04When the ignition switch is turned from ON (or START) to OFF (or ACC) positions while headlamps illuminate,
the RAP signal is supplied to terminal 10 of the headlamp battery saver control unit from smart entrance con-
trol unit terminal 5.
After counting 45 seconds by the RAP signal from the smart entrance control unit to headlamp battery saver
control unit, the ground supply to terminal 2 of the headlamp LH and RH relay from headlamp battery saver
control unit terminals 2 and 8 is terminated.
Then the headlamps are turned off.
The headlamps are turned off when driver or passenger side door is opened even if 45 seconds have not
passed after ignition switch is turned from ON (or START) to OFF (or ACC) positions while headlamps are
illuminated.
When the lighting switch is turned from OFF to 2ND after headlamps are turned to off by the battery saver
control, ground is supplied
HEADLAMP (FOR USA) Ð XENON TYPE Ð
System Description (Cont'd)
EL-32

Ito headlamp battery saver control unit terminals 5 and 13 from lighting switch terminal 11, and
Ito headlamp LH and RH relays terminal 2 from headlamp battery saver control unit terminals 2 and 8
Ithrough headlamp battery saver control unit terminals 3 and 9, and
Ithrough lighting switch terminal 12.
Then headlamps illuminate again.
AUTO LIGHT OPERATIONNBEL0188S05When lighting switch is in ªAUTOº position, ground is supplied
Ito auto light control unit terminal 10
Ifrom lighting switch terminal 42.
When ignition switch is turn to ªONº or ªSTARTº position and outside brightness is darker than prescribed level.
Ground is supplied
Ito headlamp relay LH and RH terminals 2
Ithrough battery saver control unit
Ifrom auto light control unit terminal 6, and
Ito tail lamp relay terminal 1
Ithrough battery saver control unit
Ifrom auto light control unit terminal 7.
Then both headlamp relays and tail lamp relay are energized, headlamps (low or high) and tail lamps are illu-
minate according to switch position.
Auto light operation allows headlamps and tail lamps to go off when
IIgnition switch is turned to ªOFFº position or
IOutside brightness is brighter than prescribed level.
NOTE:
The delay time is varies up to maximum of 20 seconds as the outside brightness changes.
For parking, license and tail lamp auto operation, refer to ªPARKING, LICENSE AND TAIL LAMPSº.
THEFT WARNING SYSTEMNBEL0188S06The theft warning system will flash the low beams if the system is triggered. Refer to ªTHEFT WARNING
SYSTEMº (EL-296).
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HEADLAMP (FOR USA) Ð XENON TYPE Ð
System Description (Cont'd)
EL-33

XENON HEADLAMP=NBEL0188S07Xenon type headlamp is adopted to the low beam headlamps. Xenon bulbs do not use a filament. Instead,
they produce light when a high voltage current is passed between two tungsten electrodes through a mixture
of xenon (an inert gas) and certain other metal halides. In addition to added lighting power, electronic control
of the power supply gives the headlamps stable quality and tone color.
Following are some of the many advantage of the xenon type headlamp.
IThe light produced by the headlamps is white color approximating sunlight that is easy on the eyes.
ILight output is nearly double that of halogen headlamps, affording increased area of illumination.
IThe light features a high relative spectral distribution at wavelengths to the human eye is most sensitive,
which means that even in the rain, more light is reflected back from the road surface toward the vehicle,
for added visibility.
IPower consumption is approximately 25 percent less than halogen headlamps, reducing battery load.
SEL571X
HEADLAMP (FOR USA) Ð XENON TYPE Ð
System Description (Cont'd)
EL-34

Trouble DiagnosesNBEL0189WARNING:
IThe xenon headlamp has a high-tension current generating area. Be extremely careful when remov-
ing and installing. Be certain to disconnect the battery negative cable prior to removing or install-
ing.
IWhen the xenon headlamp is lit, do not touch the harness (covered with red or amber insulation),
bulb itself or the bulb socket with your bare hands.
INever service a xenon headlamp with wet hands.
IWhen checking body side harness with a circuit tester, be certain to disconnect the harness con-
nector from the xenon headlamp.
IWhen the xenon headlamp is lit, the xenon bulb must be installed in the headlamp housing. (Never
turn on xenon headlamp, if the bulb is out of the headlamp housing.)
CAUTION:
Make sure to install the bulb securely; if the xenon bulb is improperly installed in its socket, high-ten-
sion current leaks occur. This may lead to a melted bulb and/or bulb socket.
Symptom Possible cause Repair order
Neither headlamp operates. 1. 7.5A fuse
2. Headlamp relay circuit
3. Lighting switch
4. Lighting switch ground circuit
5. Headlamp battery saver control
unit1. Check 7.5A fuse [No. 24, located in fuse block
(J/B)].
Verify battery positive voltage is present at terminal
7 of headlamp battery saver control unit.
2. Check between battery saver control unit and head-
lamp relays (LH and RH).
3. Check Lighting switch.
4. Check harness between lighting switch terminal 8
and ground.
5. Check headlamp battery saver control unit.
Headlamp LH (low and high beam)
does not operate, but headlamp
RH (low and high beam) does
operate.1. 15A fuse
2. Headlamp LH relay
3. Headlamp LH relay circuit1. Check 15A fuse (No. 60, located in fusible link and
fuse box). Verify battery positive voltage is present
at terminals 1 and 3 of headlamp LH relay.
2. Check headlamp LH relay.
3. Check harness between headlamp LH relay and
headlamp battery saver control unit.
Headlamp RH (low and high beam)
does not operate, but headlamp LH
(low and high beam) does operate.1. 15A fuse
2. Headlamp RH relay
3. Headlamp RH relay circuit1. Check 15A fuse (No. 59, located in fusible link and
fuse box). Verify battery positive voltage is present
at terminals 1 and 3 of headlamp RH relay.
2. Check headlamp RH relay.
3. Check harness between headlamp RH relay and
headlamp battery saver control unit.
LH high beam does not operate,
but LH low beam operates.1. Bulb
2. Headlamp LH relay
3. Open in the LH high beams cir-
cuit
4. Lighting switch
5. Lighting switch ground circuit1. Check bulb.
2. Check headlamp LH relay.
3. Check the following.
a. Harness between headlamp LH relay terminal 5 and
headlamp LH for open circuit.
b. Harness between headlamp LH and lighting switch
for open circuit.
4. Check lighting switch.
5. Check harness between lighting switch and ground.
HEADLAMP (FOR USA) Ð XENON TYPE Ð
Trouble Diagnoses
EL-40

Symptom Possible cause Repair order
LH low beam does not operate, but
LH high beam operates.1. 20A fuse
2. Headlamp LH relay
3. Open in the LH low beam circuit
4. LH low beam ground circuit
5. Xenon bulb
6. HID control unit
7. Booster1. Check 20A fuse (No. 32, located in fusible link and
fuse box). Verify battery positive voltage is present
at terminal 6 of headlamp LH relay.
2. Check headlamp LH relay
3. Check harness between headlamp LH relay terminal
7 and headlamp LH for open circuit.
4. Check harness between headlamp LH and ground.
5. Replace the xenon bulb with other side bulb or new
one. (If headlamps illuminate correctly, replace the
bulb.)
6. Replace the HID control unit with other side control
unit or new one. (If headlamps illuminate correctly,
replace the control unit.)
7. Replace booster as a headlamp assembly.
RH high beam does not operate,
but RH low beam operates.1. Bulb
2. Headlamp RH relay
3. Open in the RH high beams
circuit
4. Lighting switch1. Check bulb.
2. Check headlamp RH relay.
3. Check the following.
a. Harness between headlamp RH relay terminal 5 and
headlamp RH for open circuit
b. Harness between headlamp RH and lighting switch
for open circuit
4. Check lighting switch.
RH low beam does not operate,
but RH high beam operates.1. 20A fuse
2. Headlamp RH relay
3. Open in the RH low beam cir-
cuit
4. RH low beam ground circuit
5. Xenon bulb
6. HID control unit
7. Booster1. Check 20A fuse (No. 31 located in fusible link and
fuse box). Verify battery positive voltage is present
at terminal 6 of headlamp RH relay.
2. Check headlamp RH relay
3. Check harness between headlamp RH relay termi-
nal 7 and headlamp RH for open circuit.
4. Check harness between headlamp RH and ground.
5. Replace the xenon bulb with other side bulb or new
one. (If headlamps illuminate correctly, replace the
bulb.)
6. Replace the HID control unit with other side control
unit or new one. (If headlamps illuminate correctly,
replace the control unit.)
7. Replace booster as a headlamp assembly.
High beam indicator does not work. 1. Bulb
2. Open in high beam circuit1. Check bulb in combination meter.
2. Check the following.
a. Harness between headlamp LH relay and combina-
tion meter for an open circuit
b. Harness between high beam indicator and lighting
switch
Battery saver control does not
operate properly.1. RAP signal circuit
2. Door switch LH or RH circuit
3. Lighting switch circuit
4. Headlamp battery saver control
unit
5. Smart entrance control unit1. Check harness between headlamp battery saver
control unit terminal 10 and smart entrance control
unit terminal 5 for open or short circuit.
2. Check the following.
a. Harness between smart entrance control unit and
LH or RH door switch for open or short circuit.
b. LH or RH door switch ground circuit.
c. LH or RH door switch.
3. Check the following.
a. Harness between headlamp battery saver control
unit terminals 5 or 13 and lighting switch terminal 11
for open or short circuit.
b. Harness between lighting switch terminal 5 and
ground.
c. Lighting switch.
4. Check headlamp battery saver control unit.
5. Check smart entrance control unit. (EL-324)
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HEADLAMP (FOR USA) Ð XENON TYPE Ð
Trouble Diagnoses (Cont'd)
EL-41

SEL461X
2. Turn bulb socket counterclockwise with keep pushing, then
remove it.
SEL462X
3. Release retaining pin.
4. Remove the xenon bulb.
5. Install in the reverse order of removal.
CAUTION:
IWhen disposing of the xenon bulb, do not break it; always
dispose of it as is.
IMake sure to install the bulb securely; if the xenon bulb is
improperly installed in its socket, high-tension current
leaks occur. This may lead to a melted bulb and/or bulb
socket.
SEL463X
HIGH BEAMNBEL0190S021. Turn the bulb counterclockwise (LH high beam) or clockwise
(RH high beam).
2. Remove the bulb.
3. Install in the reverse order of removal.
SEL464X
Aiming AdjustmentNBEL0191LOW BEAMNBEL0191S011. Turn headlamp low beam on.
2. Use adjusting screws to perform aiming adjustment.
IFirst tighten the adjusting screw all the way and then
make adjustment by loosening the screw.
HEADLAMP (FOR USA) Ð XENON TYPE Ð
Bulb Replacement/Xenon Type (Cont'd)
EL-44

Component Parts and Harness Connector
Location
NBEL0161
SEL460X
System DescriptionNBEL0192The headlamp system for Canada vehicles contains a daytime light control unit that activates the high beam
headlamps at approximately half illumination whenever the engine is running. If the parking brake is applied
before the engine is started the daytime lights will not be illuminated. The daytime lights will illuminate once
the parking brake is released. Thereafter, the daytime lights will continue to operate when the parking brake
is applied.
And battery saver system is controlled by the headlamp battery saver control unit and smart entrance control
unit.
Power is supplied at all times
Ito headlamp LH relay terminals 1 and 3
Ithrough 15A fuse (No. 60, located in the fuse and fusible link box), and
Ito headlamp LH relay terminal 6
Ithrough 20A fuse (No. 32, located in the fuse and fusible link box), and
Ito headlamp RH relay terminals 1 and 3
Ithrough 15A fuse (No. 59, located in the fuse and fusible link box), and
Ito headlamp RH relay terminal 6
Ithrough 20A fuse (No. 31, located in the fuse and fusible link box), and
Ito headlamp battery saver control unit terminal 7, and
Ito smart entrance control unit terminal 10
Ithrough 7.5A fuse [No. 24, located in the fuse block (J/B)].
Ground is supplied
Ito daytime light control unit terminal 16,
Ito auto light control unit terminal 5 and
Ito headlamp battery saver control unit terminals 4 and 11.
When the ignition switch is in the ON or START position, power is also supplied
HEADLAMP (FOR CANADA) Ð DAYTIME LIGHT SYSTEM Ð
Component Parts and Harness Connector Location
EL-46