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EC-628
DTC P1805 BRAKE SWITCH
Revision: 2006 November2007 350Z
DTC P1805 BRAKE SWITCHPFP:25320
DescriptionNBS000GI
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-III Reference Value in Data Monitor ModeNBS000GJ
Specification data are reference values.
On Board Diagnosis LogicNBS000GK
The MIL will not light up for this self-diagnosis.
FAIL-SAFE MODE
When the malfunction is detected, the ECM enters fail-safe mode.
DTC Confirmation ProcedureNBS000GL
WITH CONSULT-III
1. Turn ignition switch ON.
2. Fully depress the brake pedal for at least 5 seconds.
3. Erase the DTC with CONSULT-III.
4. Check 1st trip DTC.
5. If 1st trip DTC is detected, go to EC-630, "
Diagnostic Procedure" .
WITH GST
Follow the procedure “WITH CONSULT-III” 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
(The 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
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DTC P1805 BRAKE SWITCH
EC-629
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Revision: 2006 November2007 350Z
Wiring DiagramNBS000GM
TBWT1663E
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EC-630
DTC P1805 BRAKE SWITCH
Revision: 2006 November2007 350Z
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 ProcedureNBS000GN
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-III or tester.
OK or NG
OK >> GO TO 4.
NG >> GO TO 3.
TER-
MINAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
122 P/L Stop lamp switch[Ignition switch: OFF]
Brake pedal: Fully released0V
[Ignition switch: OFF]
Brake pedal: Slightly depressedBATTERY VOLTAGE
(11 - 14V)
Brake pedal Stop lamp
Fully released Not illuminated
Slightly depressed Illuminated
PBIB1282E
Voltage: Battery voltage
PBIB2309E
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DTC P1805 BRAKE SWITCH
EC-631
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Revision: 2006 November2007 350Z
3. DETECT MALFUNCTIONING PART
Check the following.
10A fuse
Fuse block (J/B) connector E101
Harness for open and short between stop lamp switch and fuse
>> 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. Disconnect ECM harness connector.
2. Disconnect stop lamp switch harness connector.
3. Check harness continuity between ECM terminal 122 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 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-632, "
Component Inspection" .
OK or NG
OK >> GO TO 7.
NG >> Replace stop lamp switch.
7. CHECK INTERMITTENT INCIDENT
Refer to EC-141, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>>INSPECTION END Continuity should exist.
PBIB1282E
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EC-632
DTC P1805 BRAKE SWITCH
Revision: 2006 November2007 350Z
Component InspectionNBS000GO
STOP LAMP SWITCH
1. Disconnect stop lamp switch harness connector.
2. Check continuity between stop lamp switch terminals 3 and 4
under the following conditions.
3. If NG, adjust stop lamp switch installation, refer to BR-7,
"BRAKE PEDAL" , and perform step 2 again.
PBIB1282E
Conditions Continuity
Brake pedal: Fully released Should not exist
Brake pedal: Slightly depressed Should exist
PBIB2310E
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ASCD BRAKE SWITCH
EC-671
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Revision: 2006 November2007 350Z
ASCD BRAKE SWITCHPFP:25320
Component DescriptionNBS000I9
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-30, "
AUTOMATIC SPEED CONTROL DEVICE (ASCD)"
for the ASCD function.
CONSULT-III Reference Value in Data Monitor ModeNBS000IA
Specification data are reference values.
PBIB1282E
MONITOR ITEM CONDITION SPECIFICATION
BRAKE SW1
(ASCD brake switch)
Ignition switch: ON
Brake pedal: Fully released (A/T)
Brake pedal and clutch pedal: Fully
released (M/T)ON
Brake pedal: Slightly depressed (A/T)
Brake pedal and/or clutch pedal:
Slightly depressed (M/T)OFF
BRAKE SW2
(Stop lamp switch)
Ignition switch: ONBrake pedal: Fully released OFF
Brake pedal: Slightly depressed ON
Page 672 of 720
EC-672
ASCD BRAKE SWITCH
Revision: 2006 November2007 350Z
Wiring DiagramNBS000IB
A/T MODELS
TBWT1675E
Page 673 of 720
ASCD BRAKE SWITCH
EC-673
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Revision: 2006 November2007 350Z
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.
TER-
MINAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
122 P/L Stop lamp switch[Ignition switch: OFF]
Brake pedal: Fully released0V
[Ignition switch: OFF]
Brake pedal: Slightly depressedBATTERY VOLTAGE
(11 - 14V)
126 L/OR ASCD brake switch[Ignition switch: ON]
Brake pedal: Slightly depressed0V
[Ignition switch: ON]
Brake pedal: Fully releasedBATTERY VOLTAGE
(11 - 14V)