Lexus RX (RX 350L, RX450h) 2016-2025 Repair Manual: Tilt and Telescopic Manual Switch Circuit Malfunction (B2603)

Lexus RX (RX 350L, RX450h) 2016-2025 Repair Manual / Steering / Steering Column / Power Tilt And Power Telescopic Steering Column System / Tilt and Telescopic Manual Switch Circuit Malfunction (B2603)

DESCRIPTION

Different voltage values are sent to the multiplex tilt and telescopic ECU by operating the tilt and telescopic switch. The multiplex tilt and telescopic ECU then judges which motor and in which direction that motor should operate based on the voltage value.

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

B2603

Tilt and Telescopic Manual Switch Circuit Malfunction

When operating the tilt and telescopic switch, an abnormal voltage value is sent to the multiplex tilt and telescopic ECU.
  • Tilt and telescopic switch
  • Harness or connector
  • Multiplex tilt and telescopic ECU

WIRING DIAGRAM

PROCEDURE

1.

READ VALUE USING TECHSTREAM (TILT UP/DOWN SWITCH, TELESCOPIC SHORT/LONG SWITCH)

(a) Turn the engine switch off.

*1

Tilt and Telescopic Switch

*a

Tilt Up

*b

Tilt Down

*c

Telescopic Extend (Long)

*d

Telescopic Contract (Short)

(b) Connect the Techstream to the DLC3.

(c) Turn the engine switch on (IG).

(d) Turn the Techstream on.

(e) Check the tilt and telescopic switch.

(f) Enter the following menus: Body Electrical / Tilt & Telescopic / Data List.

Body Electrical > Tilt&Telescopic > Data List

Tester Display

Measurement Item

Range

Normal Condition

Diagnostic Note

Tilt Up Switch

Input state of tilt up switch

ON or OFF

ON: Tilt up switch activated

OFF: Tilt up switch not activated

-

Tilt Down Switch

Input state of tilt down switch

ON or OFF

ON: Tilt down switch activated

OFF: Tilt down switch not activated

-

Telesco Short Switch

Input state of telescopic contract switch

ON or OFF

ON: Telescopic contract switch activated

OFF: Telescopic contract switch not activated

-

Telesco Long Switch

Input state of telescopic extend switch

ON or OFF

ON: Telescopic extend switch activated

OFF: Telescopic extend switch not activated

-
Body Electrical > Tilt&Telescopic > Data List

Tester Display

Tilt Up Switch

Tilt Down Switch

Telesco Short Switch

Telesco Long Switch

OK:

"ON" is displayed on the Techstream screen when each switch is turned on.

"OFF" is displayed on the Techstream screen when each switch is turned off.

NG

GO TO STEP 3

OK

2.

CONFIRM DTC

(a) Clear the DTCs.

Click here

Body Electrical > Tilt&Telescopic > Clear DTCs

(b) Check for DTCs.

Click here

Body Electrical > Tilt&Telescopic > Trouble Codes

Result

Proceed to

DTCs are output.

A

DTCs are not output.

B
A

REPLACE MULTIPLEX TILT AND TELESCOPIC ECU

B

USE SIMULATION METHOD TO CHECK

3.

CHECK HARNESS AND CONNECTOR (MULTIPLEX TILT AND TELESCOPIC ECU - TILT AND TELESCOPIC SWITCH)

(a) Disconnect the J25 multiplex tilt and telescopic ECU connector.

(b) Disconnect the J34 tilt and telescopic switch connector.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

J25-5 (VC) - J34-1 (VC)

Always

Below 1 Ω

J25-18 (MSW) - J34-3 (MSW)

Always

Below 1 Ω

J25-5 (VC) or J34-1 (VC) - Body ground

Always

10 kΩ or higher

J25-18 (MSW) or J34-3 (MSW) - Body ground

Always

10 kΩ or higher
NG

REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

4.

CHECK MULTIPLEX TILT AND TELESCOPIC ECU (VC TERMINAL VOLTAGE)

(a) Reconnect the J25 multiplex tilt and telescopic ECU connector.

*a

Component with harness connected

(Multiplex Tilt and Telescopic ECU)

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

Standard Voltage:

Tester Connection

Condition

Specified Condition

J25-5 (VC) - J25-18 (MSW)

Engine switch on (IG)

4.9 to 5.1 V
NG

REPLACE MULTIPLEX TILT AND TELESCOPIC ECU

OK

5.

CHECK TILT AND TELESCOPIC SWITCH

(a) Remove the tilt and telescopic switch.

Click here

*a

Component without harness connected

(Tilt and Telescopic Switch)

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

1 (VC) - 3 (MSW)

Tilt up

342 to 378 Ω

Tilt down

1890.5 to 2089.5 Ω

Telescopic contract

750.5 to 829.5 Ω

Telescopic extend

152 to 168 Ω
OK

REPLACE MULTIPLEX TILT AND TELESCOPIC ECU

NG

REPLACE TILT AND TELESCOPIC SWITCH

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