2006 INFINITI M35 brake

EC-598
[VQ35DE]
DTC P1805 BRAKE SWITCH
Revision: 2006 January2006 M35/M45
DTC P1805 BRAKE SWITCHPFP:25320
Component DescriptionNBS0055Q
Brake switch signal is applied to the ECM through the stop lamp
switch (1) when the brake pedal is depressed. This signal is used
mainly to decrease the engine speed when the vehicle is driving.
ICC brake switch (models with ICC) (2)
ASCD brake switch (models with ASCD) (2)
CONSULT-II Reference Value in Data Monitor ModeNBS0055R
Specification data are reference values.
On Board Diagnosis LogicNBS0055S
The MIL will not light up for this diagnosis.
FAIL-SAFE MODE
When the malfunction is detected, ECM enters fail-safe mode.
PBIB2705E
MONITOR ITEM CONDITION SPECIFICATION
BRAKE SW
Ignition switch: ONBrake pedal: Fully released OFF
Brake pedal: Slightly depressed ON
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P1805
1805Brake switchA 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

DTC P1805 BRAKE SWITCH
EC-599
[VQ35DE]
C
D
E
F
G
H
I
J
K
L
MA
EC
Revision: 2006 January2006 M35/M45
DTC Confirmation ProcedureNBS0055T
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-601, "
Diagnostic Procedure"
.
WITH GST
Follow the procedure “WITH CONSULT-II” above.
SEF058Y

EC-600
[VQ35DE]
DTC P1805 BRAKE SWITCH
Revision: 2006 January2006 M35/M45
Wiring DiagramNBS0055U
TBWT0986E

DTC P1805 BRAKE SWITCH
EC-601
[VQ35DE]
C
D
E
F
G
H
I
J
K
L
MA
EC
Revision: 2006 January2006 M35/M45
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 ProcedureNBS0055V
ICC MODELS
1. CHECK DTC WITH ICC UNIT
Refer to ACS-39, "
TROUBLE DIAGNOSIS FOR SELF-DIAGNOSTIC ITEMS" .
OK or NG
OK >> GO TO 2.
NG >> Repair or replace.
2. 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 5.
NG >> GO TO 3.
TER-
MINAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
101 V/R Stop lamp switch[Ignition switch: OFF]
Brake pedal: Fully releasedApproximately 0V
[Ignition switch: OFF]
Brake pedal: Slightly depressedBATTERY VOLTAGE
(11 - 14V)
Brake pedal Stop lamp
Fully released Not illuminated
Slightly depressed Illuminated

EC-602
[VQ35DE]
DTC P1805 BRAKE SWITCH
Revision: 2006 January2006 M35/M45
3. CHECK STOP LAMP SWITCH POWER SUPPLY CIRCUIT
1. Disconnect stop lamp switch (1) harness connector.
–ICC brake switch (2)
2. Disconnect ICC brake hold relay (1) harness connector.
–: Vehicle front
3. Check voltage between stop lamp switch terminal 1 and ground
with CONSULT -II or tester.
4. Check voltage between ICC brake hold relay terminal 3 and
ground with CONSULT -II or tester.
OK or NG
OK >> GO TO 5.
NG >> GO TO 4.
PBIB2705E
PBIB2699E
Voltage: Battery voltage
PBIA9488J
Voltage: Battery voltage
PBIB2740E

DTC P1805 BRAKE SWITCH
EC-603
[VQ35DE]
C
D
E
F
G
H
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K
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MA
EC
Revision: 2006 January2006 M35/M45
4. DETECT MALFUNCTIONING PART
Check the following.
Fuse block (J/B) connector E101
10A fuse
Harness for open or short between battery and stop lamp switch
Harness for open or short between battery and ICC brake hold relay
>> Repair open circuit or short to ground or short to power in harness or connectors.
5. CHECK STOP LAMP SWITCH INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Disconnect ECM harness connector.
2. Check harness continuity between the following;
ECM terminal 101 and stop lamp switch terminal 2,
ECM terminal 101 and ICC brake hold relay terminal 5.
Refer to Wiring Diagram.
3. 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 E108, M15
Harness for open or short between ECM and stop lamp switch
Harness for open or short between ECM and ICC brake hold relay
>> Repair open circuit or short to ground or short to power in harness or connectors.
7. CHECK STOP LAMP SWITCH
Refer to EC-606, "
Component Inspection" .
OK or NG
OK >> GO TO 8.
NG >> Replace stop lamp switch.
8. CHECK ICC BRAKE HOLD RELAY
Refer to EC-584, "
Component Inspection" .
OK >> GO TO 9.
NG >> Replace ICC brake hold relay.
9. CHECK INTERMITTENT INCIDENT
Refer to EC-165, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>>INSPECTION END Continuity should exist.

EC-604
[VQ35DE]
DTC P1805 BRAKE SWITCH
Revision: 2006 January2006 M35/M45
ASCD MODELS
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 (1) harness connector.
–ASCD brake switch (2)
2. Check voltage between stop lamp switch terminal 1 and ground
with CONSULT -II or tester.
OK or NG
OK >> GO TO 4.
NG >> GO TO 3.
3. DETECT MALFUNCTIONING PART
Check the following.
Fuse block (J/B) connector E101
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.
Brake pedal Stop lamp
Fully released Not illuminated
Slightly depressed Illuminated
PBIB2705E
Voltage: Battery voltage
PBIA9488J

DTC P1805 BRAKE SWITCH
EC-605
[VQ35DE]
C
D
E
F
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H
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K
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MA
EC
Revision: 2006 January2006 M35/M45
4. 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 2.
Refer to Wiring Diagram.
3. 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.
Harness connectors E108, M15
Harness for open or short between ECM and stop lamp switch
>> Repair open circuit or short to ground or short to power in harness or connectors.
6. CHECK STOP LAMP SWITCH
Refer to EC-606, "
Component Inspection" .
OK or NG
OK >> GO TO 7.
NG >> Replace stop lamp switch.
7. CHECK INTERMITTENT INCIDENT
Refer to EC-165, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>>INSPECTION END Continuity should exist.