2005 INFINITI QX4 ignition

ASCD BRAKE SWITCH
EC-657
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Revision: October 20052005 QX56
ASCD BRAKE SWITCHPFP:25320
Component DescriptionUBS00HDO
When the brake pedal is depressed, ASCD brake switch is turned
OFF and stop lamp switch is turned ON. ECM detects the state of
the brake pedal by this input of two kinds (ON/OFF signal).
Refer to EC-29, "
AUTOMATIC SPEED CONTROL DEVICE (ASCD)"
for the ASCD function.
CONSULT-II Reference Value in Data Monitor ModeUBS00HDP
Specification data are reference values.
BBIA0373E
MONITOR ITEM CONDITION SPECIFICATION
BRAKE SW 1
(ASCD brake switch)

Ignition switch: ON
Brake pedal: Fully released ON

Brake pedal: Slightly depressed OFF
BRAKE SW 2
(Stop lamp switch)

Ignition switch: ON
Brake pedal: Fully released OFF

Brake pedal: Slightly depressed ON

ASCD BRAKE SWITCH
EC-659
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Revision: October 20052005 QX56
Specification data are reference values and are measured between each terminal and ground.
CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.
Diagnostic ProcedureUBS00HDR
1. CHECK OVERALL FUNCTION-I
With CONSULT-II
1. Turn ignition switch ON.
2. Select “BRAKE SW1” in “DATA MONITOR” mode with CONSULT-II.
3. Check “BRAKE SW1” indication under the following conditions.
Without CONSULT-II
1. Turn ignition switch ON.
2. Check voltage between ECM terminal 108 and ground under the
following conditions.
OK or NG
OK >> GO TO 2.
NG >> GO TO 3.
TER-
MINAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
101 R/W Stop lamp switch[Ignition switch: OFF]

Brake pedal: Fully releasedApproximately 0V
[Ignition switch: OFF]

Brake pedal: Slightly depressedBATTERY VOLTAGE
(11 - 14V)
108 BR/W ASCD brake switch[Ignition switch: ON]

Brake pedal: Slightly depressedApproximately 0V
[Ignition switch: ON]

Brake pedal: Fully releasedBATTERY VOLTAGE
(11 - 14V)
CONDITION INDICATION
Brake pedal: Slightly depressed OFF
Brake pedal: Fully released ON
SEC0 11D
CONDITION VOLTAGE
Brake pedal: Slightly depressed Approximately 0V
Brake pedal: Fully released Battery voltage
MBIB0061E

ASCD BRAKE SWITCH
EC-661
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Revision: October 20052005 QX56
3. CHECK ASCD BRAKE SWITCH POWER SUPPLY CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect ASCD brake switch harness connector.
3. Turn ignition switch ON.
4. Check voltage between ASCD brake switch terminal 1 and
ground with CONSULT-II or tester.
OK or NG
OK >> GO TO 5.
NG >> GO TO 4.
4. DETECT MALFUNCTIONING PART
Check the following.

Harness connectors M31, E152

Fuse block (J/B) connector M4

10A fuse

Harness for open or short between ASCD brake switch and fuse
>> Repair open circuit or short to ground or short to power in harness or connectors.
5. CHECK ASCD BRAKE SWITCH INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check harness continuity between ECM terminal 108 and ASCD brake switch terminal 2.
Refer to Wiring Diagram.
4. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 6.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
6. CHECK ASCD BRAKE SWITCH
Refer to EC-663, "
Component Inspection" .
OK or NG
OK >> GO TO 11.
NG >> Replace ASCD brake switch.
BBIA0373E
Voltage: Battery voltage
PBIB0857E
Continuity should exist.

EC-662Revision: October 2005
ASCD BRAKE SWITCH
2005 QX56
7. CHECK STOP LAMP SWITCH POWER SUPPLY CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect stop lamp switch harness connector.
3. Check voltage between stop lamp switch terminal 3 and ground
with CONSULT -II or tester.
OK or NG
OK >> GO TO 9.
NG >> GO TO 8.
8. DETECT MALFUNCTIONING PART
Check the following.

Harness connectors M31, E152

Fuse block (J/B) connector M60

10A fuse

Harness for open or short between stop lamp switch and battery
>> Repair open circuit or short to ground or short to power in harness or connectors.
9. CHECK STOP LAMP SWITCH INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Disconnect ECM harness connector.
2. Check harness continuity between ECM terminal 101 and stop lamp switch terminal 4.
Refer to Wiring Diagram.
3. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 10.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
10. CHECK STOP LAMP SWITCH
Refer to EC-663, "
Component Inspection" .
OK or NG
OK >> GO TO 11.
NG >> Replace stop lamp switch.
BBIA0373E
Voltage: Battery voltage
PBIB2102E
Continuity should exist.

ASCD BRAKE SWITCH
EC-663
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Revision: October 20052005 QX56
11 . CHECK INTERMITTENT INCIDENT
Refer to EC-156, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>>INSPECTION END
Component InspectionUBS00HDS
ASCD BRAKE SWITCH
1. Turn ignition switch OFF.
2. Disconnect ASCD brake switch harness connector.
3. Check harness continuity between ASCD brake switch terminals
1 and 2 under the following conditions.
If NG, adjust ASCD brake switch installation, refer to BR-6,
"BRAKE PEDAL" , and perform step 3 again.
STOP LAMP SWITCH
1. Turn ignition switch OFF.
2. Disconnect stop lamp switch harness connector.
3. Check harness continuity between stop lamp switch terminals 3
and 4 under the following conditions.
If NG, adjust stop lamp switch installation, refer to BR-6,
"BRAKE PEDAL" , and perform step 3 again.
Condition Continuity
Brake pedal: Fully released Should exist.
Brake pedal: Slightly depressed Should not exist.
PBIB1536E
Condition Continuity
Brake pedal: Fully released Should not exist.
Brake pedal: Slightly depressed Should exist.
PBIB2103E

EC-664Revision: October 2005
ASCD INDICATOR
2005 QX56
ASCD INDICATORPFP:24814
Component DescriptionUBS00HDT
ASCD indicator lamp illuminates to indicate ASCD operation status. Lamp has two indicators, CRUISE and
SET, and is integrated in combination meter.
CRUISE indicator illuminates when MAIN switch on ASCD steering switch is turned ON to indicate that ASCD
system is ready for operation.
SET indicator illuminates when following conditions are met.

CRUISE indicator is illuminated.

SET/COAST switch on ASCD steering switch is turned ON while vehicle speed is within the range of
ASCD setting.
SET indicator remains lit during ASCD control.
Refer to EC-29, "
AUTOMATIC SPEED CONTROL DEVICE (ASCD)" for the ASCD function.
CONSULT-II Reference Value in Data Monitor ModeUBS00HDU
Specification data are reference value.
MONITOR ITEM CONDITION SPECIFICATION
CRUISE LAMP

Ignition switch: ON
MAIN switch: Pressed at the 1st
time → at the 2nd timeON → OFF
SET LAMP

MAIN switch: ON

When vehicle speed is
between 40 km/h (25 MPH)
and 144 km/h (89 MPH)

ASCD: Operating ON

ASCD: Not operating OFF

EC-666Revision: October 2005
ASCD INDICATOR
2005 QX56
Diagnostic ProcedureUBS00HDW
1. CHECK OVERALL FUNCTION
Check ASCD indicator under the following conditions.
OK or NG
OK >>INSPECTION END
NG >> GO TO 2.
2. CHECK DTC
Check that DTC U1000 or U1001 is not displayed.
OK or NG
OK >> GO TO 3.
NG >> Perform trouble diagnosis for DTC U1000, U1001. Refer to EC-163, "
DTC U1000, U1001 CAN
COMMUNICATION LINE" .
3. CHECK COMBINATION METER FUNCTION
Refer to DI-5, "
COMBINATION METERS" .
OK or NG
OK >> GO TO 4.
NG >> Go to DI-5, "
COMBINATION METERS" .
4. CHECK INTERMITTENT INCIDENT
Refer to EC-156, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>>INSPECTION END
ASCD INDICATOR CONDITION SPECIFICATION
CRUISE LAMP

Ignition switch: ON
MAIN switch: Pressed at the 1st
time → at the 2nd timeON → OFF
SET LAMP

MAIN switch: ON

When vehicle speed is between
40 km/h (25 MPH) and 144 km/h
(89 MPH)

ASCD: Operating ON

ASCD: Not operating OFF

SERVICE DATA AND SPECIFICATIONS (SDS)
EC-669
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Revision: October 20052005 QX56
SERVICE DATA AND SPECIFICATIONS (SDS)PFP:00030
Fuel PressureUBS00HE9
Idle Speed and Ignition TimingUBS00HEA
*: Under the following conditions:

Air conditioner switch: OFF

Electric load: OFF (Lights and heater fan)

Steering wheel: Kept in straight-ahead position
Calculated Load ValueUBS00HEB
Mass Air Flow SensorUBS00HEC
*: Engine is warmed up to normal operating temperature and running under no load.
Intake Air Temperature SensorUBS00HED
Engine Coolant Temperature SensorUBS00HEE
A/F Sensor 1 HeaterUBS00HEF
Heated Oxygen sensor 2 HeaterUBS00HEG
Crankshaft Position Sensor (POS)UBS00HEH
Refer to EC-290, "Component Inspection" .
Camshaft Position Sensor (PHASE)UBS00HEI
Refer to EC-297, "Component Inspection" .
Throttle Control MotorUBS00HEJ
Fuel pressure at idling kPa (kg/cm2 , psi)Approximately 350 (3.57, 51)
Target idle speed
No-load* (in P or N position)650±50 rpm
Air conditioner: ON In P or N position 700 rpm or more
Ignition timing In P or N position 15° ± 5° BTDC
Condition Calculated load value % (Using CONSULT-II or GST)
At idle14.0 - 33.0
At 2,500 rpm12.0 - 25.0
Supply voltage Battery voltage (11 - 14V)
Output voltage at idle1.0 - 1.3V*
Mass air flow (Using CONSULT-II or GST)3.0 - 9.0 g·m/sec at idle*
9.0 - 28.0 g·m/sec at 2,500 rpm*
Temperature °C (°F) Resistance kΩ
25 (77)1.94 - 2.06
80 (176)0.295 - 0.349
Temperature °C (°F) Resistance kΩ
20 (68)2.1 - 2.9
50 (122)0.68 - 1.00
90 (194)0.236 - 0.260
Resistance [at 25°C (77°F)] 2.3 - 4.3Ω
Resistance [at 25°C (77°F)] 5.0 - 7.0Ω
Resistance [at 25°C (77°F)] Approximately 1 - 15Ω