Dtc B278A Short To Gnd In Immobiliser System Power Source Circuit

Securities. Camry. Acv40 Gsv40
Engine Immobiliser. Camry. Acv40 Gsv40

DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

CHECK DTC OUTPUT

CHECK HARNESS AND CONNECTOR (CERTIFICATION ECU - ENGINE SWITCH)

CHECK HARNESS AND CONNECTOR (ENGINE SWITCH - POWER SOURCE AND BODY GROUND)

DTC B278A Short to GND in Immobiliser System Power Source Circuit


DESCRIPTION

This DTC is stored when the engine switch power source supply line is open or shorted.

DTC Code
DTC Detection Condition
Trouble Area
B278A
Engine switch power source supply line is open or shorted.
  1. Wire harness or connector
  2. Engine switch
  3. Certification ECU (Smart key ECU assembly)

WIRING DIAGRAM


Camry. Acv40 Gsv40.Engine Immobiliser.Engine Immobiliser System (W/ Entry And Start System). Dtc B278A Short To Gnd In Immobiliser System Power Source Circuit


INSPECTION PROCEDURE

NOTICE:
If the certification ECU (smart key ECU assembly) is replaced, register all the keys.
1.CHECK DTC OUTPUT

  1. Clear the DTCs (CAMRY_ACV40 RM000001GV802CX.html).

  1. Recheck for DTCs (CAMRY_ACV40 RM000001GV802CX.html).

    OK:
    B278A output does not recur.


NG
Go to step 2
OK

USE SIMULATION METHOD TO CHECK (CAMRY_ACV40 RM000000UZ104DX.html)

2.CHECK HARNESS AND CONNECTOR (CERTIFICATION ECU - ENGINE SWITCH)

  1. Disconnect the certification ECU (smart key ECU assembly) connector.



    Camry. Acv40 Gsv40.Engine Immobiliser.Engine Immobiliser System (W/ Entry And Start System). Dtc B278A Short To Gnd In Immobiliser System Power Source Circuit

  1. Disconnect the engine switch connector.

  1. Measure the resistance according to the value(s) in the table below.

    Standard Resistance:
    Tester Connection
    		Condition
    		Specified Condition
    E74-30 (VC5) - E70-14 (VC5)
    		Always
    		Below 1 Ω
    E74-40 (AGND) - E70-8 (AGND)
    		Always
    		Below 1 Ω
    E74-30 (VC5) - Body ground
    		Always
    		10 kΩ or higher
    E74-40 (AGND) - Body ground
    		Always
    		10 kΩ or higher


NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK


3.CHECK HARNESS AND CONNECTOR (ENGINE SWITCH - POWER SOURCE AND BODY GROUND)

  1. Reconnect the certification ECU (smart key ECU assembly) connector.



    Camry. Acv40 Gsv40.Engine Immobiliser.Engine Immobiliser System (W/ Entry And Start System). Dtc B278A Short To Gnd In Immobiliser System Power Source Circuit

  1. Reconnect the engine switch connector.

  1. Measure the voltage according to the value(s) in the table below.

    Standard Voltage:
    Tester Connection
    		Condition
    		Specified Condition
    E74-30 (VC5) - Body ground
    		Key not in cabin
    		Below 1 V
    E74-30 (VC5) - Body ground
    		Brake pedal depressed
    		4.6 to 5.4 V

  1. Measure the resistance according to the value(s) in the table below.

    Standard Resistance:
    Tester Connection
    		Condition
    		Specified Condition
    E74-40 (AGND) - Body ground
    		Always
    		Below 1 Ω


NG
REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)
OK

REPLACE ENGINE SWITCH (CAMRY_ACV40 RM0000026WR00UX.html)