Infiniti M45 (Y34). Manual - part 480

DTC P1780 SHIFT CHANGE SIGNAL

EC-609

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3. 

REPLACE ECM

1.

Replace ECM.

2.

Perform initialization of IVIS (NATS) system and registration of all IVIS (NATS) ignition key IDs. Refer to

BL-174, "ECM Re-Communicating Function"

 .

3.

Perform 

EC-44, "Accelerator Pedal Released Position Learning"

 .

4.

Perform 

EC-44, "Throttle Valve Closed Position Learning"

 .

5.

Perform 

EC-44, "Idle Air Volume Learning"

 .

>> INSPECTION END

EC-610

DTC P1805 BRAKE SWITCH

DTC P1805 BRAKE SWITCH

PFP:25320

Description

ABS002SF

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 Mode

ABS002SG

Specification data are reference values.

On Board Diagnosis Logic

ABS002SH

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 Procedure

ABS002SI

 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-612, "Diagnostic Procedure"

.

 WITH GST

Follow the procedure WITH CONSULT-II above.

MONITOR ITEM

CONDITION

SPECIFICATION

BRAKE SW

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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 an 
extremely long time while the vehicle is driving.

●

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

●

Stop lamp switch

Engine operation condition in fail-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

PBIB1952E

DTC P1805 BRAKE SWITCH

EC-611

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Wiring Diagram

ABS002SJ

TBWA0303E

EC-612

DTC P1805 BRAKE SWITCH

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 Procedure

ABS002SK

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 

COLOR

ITEM

CONDITION

DATA (DC Voltage)

106

R/W

Stop lamp switch

[Ignition switch: OFF]

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Brake pedal: Fully released

Approximately 0V

[Ignition switch: OFF]

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Brake pedal: Slightly depressed

BATTERY VOLTAGE
(11 - 14V)

Brake pedal

Stop lamp

Fully released

Not illuminated

Slightly depressed

Illuminated

PBIB0034E

Voltage: Battery voltage

PBIB0117E