DTC    B2602    Key Unlock Warning Switch Circuit Malfunction

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DESCRIPTION

A signal (ON or OFF) is sent from the driver side J/B ECU to the multiplex tilt & telescopic ECU via the communication bus when the ignition key is inserted into the key cylinder. The multiplex tilt & telescopic ECU uses this signal to operate the auto away or auto return function.

DTC No.
Detection Item
Trouble Area
B2602
  1. The multiplex tilt & telescopic ECU receives a key unlock warning switch ON signal after receiving an ignition switch ON signal.
  2. The multiplex tilt & telescopic ECU receives an ignition switch OFF signal after receiving a key unlock warning switch OFF signal.
  3. A signal (OFF) is sent to the multiplex tilt & telescopic ECU when the ignition switch is turned to the ON position.
  1. Unlock warning switch assembly
  2. Wire harness or connector
  3. Driver side J/B ECU
  4. Multiplex tilt & telescopic ECU

WIRING DIAGRAM


C104132E04


INSPECTION PROCEDURE

1.CHECK OTHER DTC OUTPUT

HINT:
The power tilt & telescopic steering column system uses the multiplex communication system, so check its diagnostic system before proceeding to troubleshooting.

  1. Check if the power tilt & telescopic steering column system DTC B2621 is output.

    Result:

    DTC Condition
    		Proceed to
    No output
    		A
    B2621 is output
    		B

    HINT:
    1. If DTC B2621 besides B2602 is output, perform troubleshooting for this DTC first.
    2. DTC B2621 indicates a communication interruption.



B
REPAIR CIRCUIT INDICATED BY OUTPUT CODE
A


2.READ VALUE OF INTELLIGENT TESTER

  1. Connect the intelligent tester to the DLC3.

  1. Turn the ignition switch to the ON position and turn the intelligent tester on.

  1. Select "Tilt & Telescopic".

  1. Touch the "Data List" button.

  1. Select "Key Switch (MPX)".

  1. Check the communication state on the tester screen.

    TILT & TELESCOPIC:

    Item
    		Measurement Item/Range (Display)
    		Normal Condition
    Key Switch (MPX)
    		Communication state of unlock warning switch/ON or OFF
    		ON: Communication is normal
    OFF: Communication is interrupted

    OK:
    "ON" is displayed.



OK
REPLACE MULTIPLEX TILT & TELESCOPIC ECU
NG


3.INSPECT UNLOCK WARNING SWITCH ASSEMBLY
F040700E01

  1. Disconnect the K6 connector from the unlock warning switch assembly.

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

    Resistance:
    Tester Connection (Terminal No.)
    		Condition
    		Specified Condition
    UN+ (2) - UN- (1)
    		Unlock warning switch OFF (Ignition key is removed)
    		10 kΩ or higher
    UN+ (2) - UN- (1)
    		Unlock warning switch ON (Ignition key is inserted)
    		Below 1 Ω



NG
REPLACE UNLOCK WARNING SWITCH ASSEMBLY
OK


4.CHECK HARNESS AND CONNECTOR (BETWEEN BODY ECU AND UNLOCK WARNING SWITCH ASSEMBLY)
F044880E03

  1. Disconnect the B6 connector from the multiplex network body ECU.

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

    Resistance:
    Tester Connection (Terminal No.)
    		Condition
    		Specified Condition
    KSW (B6-21) - UN+ (K6-2)
    		Always
    		Below 1 Ω
    KSW (B6-21) - Body ground
    		Always
    		10 kΩ or higher



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK


5.CHECK HARNESS AND CONNECTOR (BETWEEN UNLOCK WARNING SWITCH ASSEMBLY AND BODY GROUND)


    F044883E03

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

    Resistance:
    Tester connection (Terminal No.)
    		Condition
    		Specified value
    UN- (K6-1) - Body ground
    		Always
    		Below 1 Ω



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

REPLACE MULTIPLEX TILT & TELESCOPIC ECU