2004 INFINITI FX35 brake light

EC-550
[VQ35DE]
DTC P1805 BRAKE SWITCH
Revision: 2004 November 2004 FX35/FX45
DTC P1805 BRAKE SWITCHPFP:25320
DescriptionABS006X1
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 ModeABS006X2
Specification data are reference values.
On Board Diagnosis LogicABS006X3
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 ProcedureABS006X4
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.
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-552, "
Diagnostic Procedure"
.
WITH GST
Follow the procedure “WITH CONSULT-II” above.
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
SEF058Y

EC-552
[VQ35DE]
DTC P1805 BRAKE SWITCH
Revision: 2004 November 2004 FX35/FX45
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 ProcedureABS006X6
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 1 and ground
with CONSULT-II or tester.
OK or NG
OK >> GO TO 4.
NG >> GO TO 3.
TER-
MINAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
101 P/L 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
PBIB1605E
PBIB1184E
Voltage: Battery voltage

EC-554
[VQ35DE]
DTC P1805 BRAKE SWITCH
Revision: 2004 November 2004 FX35/FX45
Component InspectionABS006X7
STOP LAMP SWITCH
1. Disconnect stop lamp switch harness connector.
2. Check continuity between stop lamp switch terminals 1 and 2
under the following conditions.
3. If NG, adjust stop lamp switch installation, refer to BR-6, "
BRAKE PEDAL" , and perform step 2 again.
PBIB1605E
Conditions Continuity
Brake pedal is fully released Should not exist.
Brake pedal is slightly depressed Should exist.
PBIB1185E

ICC BRAKE SWITCH
EC-615
[VQ35DE]
C
D
E
F
G
H
I
J
K
L
MA
EC
Revision: 2004 November 2004 FX35/FX45
ICC BRAKE SWITCHPFP:25320
Component DescriptionABS006YS
When the brake pedal is depressed, ICC 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 ACS-6, "
DESCRIPTION" for the ICC function.
CONSULT-II Reference Value in Data Monitor ModeABS006YT
Specification data are reference values.
PBIB1539E
MONITOR ITEM CONDITION SPECIFICATION
BRAKE SW1
(ICC brake switch)

Ignition switch: ON
Brake pedal: Fully released ON

Brake pedal: Slightly depressed OFF
BRAKE SW2
(stop lamp switch)

Ignition switch: ON
Brake pedal: Fully released OFF

Brake pedal: Slightly depressed ON

ICC BRAKE SWITCH
EC-617
[VQ35DE]
C
D
E
F
G
H
I
J
K
L
MA
EC
Revision: 2004 November 2004 FX35/FX45
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 ProcedureABS00DAJ
1. CHECK OVERALL FUNCTION-I
With CONSULT-II
1. Turn ignition switch “ON”.
2. Select “BRAKE SW1” in “DATA MONITOR” mode with CON-
SULT-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.
TERMI-
NAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
101 P/L Stop lamp switch[Ignition switch: OFF]

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

Brake pedal: Slightly depressedBATTERY VOLTAGE
(11 - 14V)
108 SB ICC brake switch[Ignition switch: ON]

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

Brake pedal: Fully releasedBATTERY VOLTAGE
(11 - 14V)
CONDITION INDICATION
When brake pedal is depressed OFF
When brake pedal is fully released ON
SEC011D
CONDITION VOLTAGE
When brake pedal is depressed Approximately 0V
When brake pedal is fully released Battery voltage
MBIB0061E

EC-622
[VQ35DE]
ICC BRAKE SWITCH
Revision: 2004 November 2004 FX35/FX45
15. DETECT MALFUNCTIONING PART
Check the following.

Harness connectors E211, M41

Joint connector-2

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.
16. CHECK STOP LAMP SWITCH
Refer to EC-1301, "
Component Inspection"
OK or NG
OK >> GO TO 17.
NG >> Replace stop lamp switch.
17. CHECK INTERMITTENT INCIDENT
Refer to EC-784, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>>INSPECTION END
Component InspectionABS006YW
ICC BRAKE SWITCH
1. Turn ignition switch OFF.
2. Disconnect ICC brake switch harness connector.
3. Check continuity between ICC brake switch terminals 1 and 2
under the following conditions.
If NG, adjust ICC 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 continuity between stop lamp switch terminals 1 and 2
under the following conditions.
If NG, adjust stop lamp switch installation, refer to BR-6,
"BRAKE PEDAL" , and perform step 3 again.
ICC BRAKE HOLD RELAY
1. Apply 12V direct current between ICC brake hold relay terminals 1 and 2.
Condition Continuity
When brake pedal is fully released. Should exist.
When brake pedal is slightly depressed. Should not exist.
SEC023D
Condition Continuity
When brake pedal is fully released. Should not exist.
When brake pedal is slightly depressed. Should exist.
PBIB1185E

EC-624
[VQ35DE]
ASCD BRAKE SWITCH
Revision: 2004 November 2004 FX35/FX45
ASCD BRAKE SWITCHPFP:25320
Component DescriptionABS006YX
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-657, "
AUTOMATIC SPEED CONTROL DEVICE
(ASCD)" for the ASCD function.
CONSULT-II Reference Value in Data Monitor ModeABS006YY
Specification data are reference values.
PBIB1089E
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

EC-626
[VQ35DE]
ASCD BRAKE SWITCH
Revision: 2004 November 2004 FX35/FX45
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 ProcedureABS006Z0
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 P/L Stop lamp switch[Ignition switch: OFF]

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

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

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

Brake pedal: Fully releasedBATTERY VOLTAGE
(11 - 14V)
CONDITION INDICATION
When brake pedal is slightly depressed OFF
When brake pedal is fully released ON
SEC011D
CONDITION VOLTAGE
When brake pedal is slightly depressed Approximately 0V
When brake pedal is fully released Battery voltage
MBIB0061E