2006 INFINITI QX56 ignition

DTC P1805 BRAKE SWITCHEC-523
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Revision: November 2009 2006 QX56
DTC P1805 BRAKE SWITCHPFP:25320
DescriptionUBS00HBX
Brake switch signal is applied to the ECM through the stop lamp switch when the brake pedal is depressed.
This signal is used mainly to decrease the engine speed when the vehicle is driving.
CONSULT-II Reference Value in Data Monitor ModeUBS00HBY
Specification data are reference values.
On Board Diagnosis LogicUBS00HBZ
The MIL will not light up for this diagnosis.
FAIL-SAFE MODE
When the malfunction is detected, the ECM enters fail-safe mode.
DTC Confirmation ProcedureUBS00HC0
WITH CONSULT-II
1. Turn ignition switch ON.
2. Fully depress the brake pedal for at least 5 seconds.
3. Erase the DTC with CONSULT-II.
4. Select “DATA MONITOR ” mode with CONSULT-II.
5. If 1st trip DTC is detected, go to EC-525, "
Diagnostic Procedure"
.
WITH GST
Follow the procedure “WITH CONSULT-II” above.
MONITOR ITEM CONDITION SPECIFICATION
BRAKE SW

Ignition switch: ON Brake pedal: Fully released
OFF
Brake pedal: Slightly depressed ON
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P1805
1805 Brake switch A brake switch signal is not sent to ECM for
extremely long time while the vehicle is driving.

Harness or connectors
(Stop lamp switch circuit is open or
shorted.)

Stop lamp switch
Engine operating condition in fail-safe mode
ECM controls the electric throttle control actuator by regulating the throttle opening to a small range.
Therefore, acceleration will be poor. Vehicle condition Driving condition
When engine is idling Normal When accelerating Poor acceleration
SEF058Y

DTC P1805 BRAKE SWITCHEC-525
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Revision: November 2009 2006 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 ProcedureUBS00HC2
1. CHECK STOP LAMP SWITCH CIRCUIT
1. Turn ignition switch OFF.
2. Check the stop lamp when depressing and releasing the brake pedal.
OK or NG
OK >> GO TO 4.
NG >> GO TO 2.
2. CHECK STOP LAMP SWITCH POWER SUPPLY CIRCUIT
1. Disconnect stop lamp switch harness connector.
2. Check voltage between stop lamp switch terminal 3 and ground with CONSULT-II or tester.
OK or NG
OK >> GO TO 4.
NG >> GO TO 3.
TER-
MINAL NO. WIRE
COLOR ITEM
CONDITION DATA (DC Voltage)
101 R/W Stop lamp switch [Ignition switch: OFF]

Brake pedal: Fully released
Approximately 0V
[Ignition switch: OFF]

Brake pedal: Slightly depressed BATTERY VOLTAGE
(11 - 14V)
Brake pedal
Stop lamp
Fully released Not illuminated
Slightly depressed Illuminated
BBIA0373E
Voltage: Battery voltage
PBIB2102E

EC-526Revision: November 2009
DTC P1805 BRAKE SWITCH
2006 QX56
3. DETECT MALFUNCTIONING PART
Check the following.

Harness connectors M31, E152

Fuse block (J/B) connector M60

10A fuse

Harness for open and short between stop lamp switch and battery
>> Repair open circuit or short to ground or short to power in harness or connectors.
4. CHECK STOP LAMP 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 101 and stop lamp switch terminal 4. Refer to Wiring Diagram.
4. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 5.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
5. CHECK STOP LAMP SWITCH
Refer to EC-527, "
Component Inspection" .
OK or NG
OK >> GO TO 6.
NG >> Replace stop lamp switch.
6. CHECK INTERMITTENT INCIDENT
Refer to EC-144, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>> INSPECTION END
Continuity should exist.

EC-528Revision: November 2009
DTC P2100, P2103 THROTTLE CONTROL MOTOR RELAY
2006 QX56
DTC P2100, P2103 THROTTLE CONTROL MOTOR RELAYPFP:16119
Component DescriptionUBS00N77
Power supply for the throttle control motor is provided to the ECM via throttle control motor relay. The throttle
control motor relay is ON/OFF controlled by the ECM. When the ignition switch is turned ON, the ECM sends
an ON signal to throttle control motor relay and battery voltage is provided to the ECM. When the ignition
switch is turned OFF, the ECM sends an OFF signal to throttle control motor relay and battery voltage is not
provided to the ECM.
CONSULT-II Reference Value in Data Monitor ModeUBS00N78
Specification data are reference values.
On Board Diagnosis LogicUBS00N79
These self-diagnoses have the one trip detection logic.
FAIL-SAFE MODE
When the malfunction is detected, ECM enters fail-safe mode and the MlL lights up.
DTC Confirmation ProcedureUBS00N7A
NOTE:
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
PROCEDURE FOR DTC P2100 With CONSULT-II
1. Turn ignition switch ON and wait at least 2 seconds.
2. Select “DATA MONITOR ””mode with CONSULT-II.
3. Start engine and let it idle for 5 seconds.
4. If DTC is detected, go to EC-531, "
Diagnostic Procedure" .
With GST
Follow the procedure “With CONSULT-II” above.
MONITOR ITEM CONDITIONSPECIFICATION
THRTL RELAY

Ignition switch: ON ON
DTC No. Trouble diagnosis nameDTC detecting condition Possible cause
P2100
2100 Throttle control motor
relay circuit open ECM detects a voltage of power source for
throttle control motor is excessively low.

Harness or connectors
(Throttle control motor relay circuit is
open)

Throttle control motor relay
P2103
2103 Throttle control motor
relay circuit short ECM detect the throttle control motor relay is
stuck ON.

Harness or connectors
(Throttle control motor relay circuit is
shorted)

Throttle control motor relay
Engine operating condition in fail-safe mode
ECM stops the electric throttle control actuator control, throttle valve is maintained at a fixed opening (approx. 5 degrees) b y the return
spring.
SEF058Y

DTC P2100, P2103 THROTTLE CONTROL MOTOR RELAYEC-529
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Revision: November 2009 2006 QX56
PROCEDURE FOR DTC P2103
TESTING CONDITION:
Before performing the following procedure, confirm that battery voltage is more than 8V.
With CONSULT-II
1. Turn ignition switch ON and wait at least 1 second.
2. Select “DATA MONITOR ” mode with CONSULT-II.
3. If DTC is detected, go to EC-531, "
Diagnostic Procedure" .
With GST
Follow the procedure “With CONSULT-II” above.
SEF058Y

DTC P2100, P2103 THROTTLE CONTROL MOTOR RELAYEC-531
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Revision: November 2009 2006 QX56
Specification data are reference values and are measured between each terminal and ground.
Pulse signal is measured by CONSULT-II.
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.
: Average voltage for pulse signal (Actual pulse signal can be confirmed by oscilloscope.)
Diagnostic ProcedureUBS00N7C
1. CHECK THROTTLE CONTROL MOTOR RELAY POWER SUPPLY CIRCUIT-I
1. Turn ignition switch OFF.
2. Check voltage between ECM terminal 104 and ground with CONSULT-II or tester.
OK or NG
OK >> GO TO 4.
NG >> GO TO 2.
TER-
MINAL NO. WIRE
COLOR ITEM
CONDITION DATA (DC Voltage)
3L Throttle control motor relay
power supply [Ignition switch: ON] BATTERY VOLTAGE
(11 - 14V)
4L/W Throttle control motor
(Close) [Ignition switch: ON]

Engine: Stopped

Selector lever: D

Accelerator pedal: Released 0 - 14V
5L/B Throttle control motor
(Open) [Ignition switch: ON]

Engine: Stopped

Selector lever: D

Accelerator pedal: Fully depressed 0 - 14V
104 O Throttle control motor relay [Ignition switch: OFF]BATTERY VOLTAGE
(11 - 14V)
[Ignition switch: ON] 0 - 1.0V
PBIB1104E
PBIB1105E
Voltage: Battery voltage
PBIB1171E

EC-532Revision: November 2009
DTC P2100, P2103 THROTTLE CONTROL MOTOR RELAY
2006 QX56
2. CHECK THROTTLE CONTROL MOTOR RELAY POWER SUPPLY CIRCUIT-II
1. Disconnect ECM harness connector.
2. Disconnect IPDM E/R harness connector E122.
3. Check continuity between ECM terminal 104 and IPDM E/R terminal 47. Refer to Wiring Diagram.
4. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 3.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
3. CHECK FUSE
1. Disconnect 20A fuse.
2. Check 20A fuse for blown.
OK or NG
OK >> GO TO 7.
NG >> Replace 20A fuse.
4. CHECK THROTTLE CONTROL MOTOR RELAY INPUT SIGNAL CIRCUIT-I
Check voltage between ECM terminal 3 and ground under the fol-
lowing conditions with CONSULT-II or tester.
OK or NG
OK >> GO TO 7.
NG >> GO TO 5.
5. CHECK THROTTLE CONTROL MOTOR RELAY INPUT SIGNAL CIRCUIT-II
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Disconnect IPDM E/R harness connector E119.
4. Check continuity between ECM terminal 3 and IPDM E/R terminal 6. Refer to Wiring Diagram.
5. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 7.
NG >> GO TO 6.
6. DETECT MALFUNCTIONING PART
Check the following.

Harness connectors E2, F32

Harness for open or short between ECM and IPDM E/R
>> Repair open circuit or short to ground or short to power in harness or connectors.
Continuity should exist.
Ignition switch
Voltage
OFF Approximately 0V
ON Battery voltage
(11 - 14V)
MBIB0028E
Continuity should exist.

EC-534Revision: November 2009
DTC P2101 ELECTRIC THROTTLE CONTROL FUNCTION
2006 QX56
DTC P2101 ELECTRIC THROTTLE CONTROL FUNCTIONPFP:16119
DescriptionUBS00H7I
NOTE:
If DTC P2101 is displayed with DTC P2100 or 2119, first perform the trouble diagnosis for DTC P2100
or P2119. Refer to EC-528, "
DTC P2100, P2103 THROTTLE CONTROL MOTOR RELAY" or EC-545,
"DTC P2119 ELECTRIC THROTTLE CONTROL ACTUATOR" .
Electric throttle control actuator consists of throttle control motor, throttle position sensor, etc.
The throttle control motor is operated by the ECM and it opens and closes the throttle valve.
The current opening angle of the throttle valve is detected by the throttle position sensor and it provides feed-
back to the ECM to control the throttle control motor to make the throttle valve opening angle properly in
response to driving condition.
On Board Diagnosis LogicUBS00H7J
This self-diagnosis has the one trip detection logic.
FAIL-SAFE MODE
When the malfunction is detected, ECM enters fail-safe mode and the MIL lights up.
DTC Confirmation ProcedureUBS00H7K
NOTE:
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
TESTING CONDITION:
Before performing the following procedure, confirm that battery voltage is more than 11V when engine
is running.
WITH CONSULT-II
1. Turn ignition switch ON and wait at least 2 seconds.
2. Select “DATA MONITOR ” mode with CONSULT-II.
3. Start engine and let it idle for 5 seconds.
4. If DTC is detected, go to EC-536, "
Diagnostic Procedure" .
WITH GST
Follow the procedure “WITH CONSULT-II” above.
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P2101
2101 Electric throttle control
performance Electric throttle control function does not oper-
ate properly.

Harness or connectors
(Throttle control motor circuit is open or
shorted)

Electric throttle control actuator
Engine operating condition in fail-safe mode
ECM stops the electric throttle control actuator control, throttle valve is maintained at a fixed opening (approx. 5 degrees) by the return
spring.
SEF058Y