B2602

STEERING COLUMN: POWER TILT AND POWER TELESCOPIC STEERING COLUMN SYSTEM: B2602: Key Unlock Warning Switch Circuit Malfunction

DTC B2602 - Key Unlock Warning Switch Circuit Malfunction

DESCRIPTION

A signal (ON or OFF) is sent from the multiplex network body ECU to the multiplex tilt and telescopic ECU via the communication bus when the ignition key is inserted into the key cylinder. The multiplex tilt and telescopic ECU uses this signal to operate the auto away or auto return function.






WIRING DIAGRAM





INSPECTION PROCEDURE

PROCEDURE

1. CHECK OTHER DTC OUTPUT
HINT: The power tilt and telescopic steering column system uses the multiplex communication system, so check its diagnostic system before proceeding to troubleshooting.
(a) Check if the power tilt and telescopic steering column system DTC B2621 is output.
Result:





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

B -- REPAIR CIRCUIT INDICATED BY OUTPUT DTC
A -- Continue to next step.
2. READ VALUE USING INTELLIGENT TESTER
(a) Connect the intelligent tester to the DLC3.
(b) Turn the ignition switch to the ON position and turn the intelligent tester on.
(c) Select "KEY SW (MPX)" from the Data List.
(d) Check the communication state on the tester screen.
TILT & TELESCOPIC:






OK:
"ON" is displayed.
OK -- REPLACE MULTIPLEX TILT & TELESCOPIC ECU
NG -- Continue to next step.
3. INSPECT UNLOCK WARNING SWITCH ASSEMBLY
(a) Disconnect the K4 connector from the unlock warning switch assembly.





(b) Measure the resistance according to the value(s) in the table below.
Standard resistance:






NG -- REPLACE UNLOCK WARNING SWITCH ASSEMBLY
OK -- Continue to next step.
4. CHECK HARNESS AND CONNECTOR (MULTIPLEX NETWORK BODY ECU - UNLOCK WARNING SWITCH ASSEMBLY)
(a) Disconnect the B4 connector from the multiplex network body ECU.





(b) Measure the resistance according to the value(s) in the table below.
Standard resistance:






NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
5. CHECK HARNESS AND CONNECTOR (UNLOCK WARNING SWITCH ASSEMBLY - BODY GROUND)





(a) Measure the resistance according to the value(s) in the table below.
Standard resistance:






NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- REPLACE MULTIPLEX TILT & TELESCOPIC ECU