Power Tilt & Telescopic Steering Column (Diagnostic Codes & Circuit Tests): Overview Lexus HS I

DESCRIPTION

Different voltage values are input 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 be moved based on the voltage value.

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1. READ VALUE USING TECHSTREAM (TILT UP/DOWN SWITCH, TELESCOPIC SHORT/LONG SWITCH) Turn the power switch off. Connect the Techstream to the DLC3. Turn the power switch on (IG). Turn the Techstream on. Check the tilt and telescopic manual switch. Enter the following menus: Body Electrical / Tilt & Telescopic / Data List. TILT & TELESCOPIC Tester Display Measurement Item/Range Normal Condition Diagnostic Note Telesco Short Switch Input state of telescopic short by manual switch/ OFF or ON OFF: Telescopic short not activated by manual switch ON: Telescopic short activated by manual switch - Telesco Long Switch Input state of telescopic long by manual switch/ OFF or ON OFF: Telescopic long not activated by manual switch ON: Telescopic long activated by manual switch - Tilt Down Switch Input state of tilt down by manual switch/ OFF or ON OFF: Tilt down not activated by manual switch ON: Tilt down activated by manual switch - Tilt Up Switch Input state of tilt up by manual switch/ OFF or ON OFF: Tilt up is not activated by manual switch ON: Tilt up is activated by manual 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. TEXT IN ILLUSTRATION *1 Tilt Up *2 Tilt Down *3 Telescopic Extend (Long) *4 Telescopic Contract (Short) NG --> See step 3 OK: Go to next step
2. CONFIRM DTC Clear the DTC. Refer to «DTC CHECK / CLEAR»(ref-398292-S30851665012011051600000) . Check for DTCs. Refer to «DTC CHECK / CLEAR»(ref-398292-S30851665012011051600000) . RESULT Result Proceed to DTC is output. A DTC is not output. B B --> See step 6 A --> See step 7
3. CHECK HARNESS AND CONNECTOR (MULTIPLEX TILT AND TELESCOPIC ECU - TILT AND TELESCOPIC SWITCH) Disconnect the F109 multiplex tilt and telescopic ECU connector. Disconnect the F20 headlight dimmer switch assembly connector. Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition F109-4 (VC) - F20-8 (VC) Always Below 1 ohms F109-3 (MSW) - F20-10 (MSW) F20-8 (VC) - Body ground Always 10 kohms or higher F20-10 (MSW) - Body ground NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR OK: Go to next step
4. CHECK MULTIPLEX TILT AND TELESCOPIC ECU (VC TERMINAL VOLTAGE) Reconnect the F109 multiplex tilt and telescopic ECU connector. Measure the voltage according to the value(s) in the table below. Standard Voltage Tester Connection Switch Condition Specified Condition F109-4 (VC) - F109-3 (MSW) Power switch on (IG) 4.9 to 5.1 V TEXT IN ILLUSTRATION *1 Component with harness connected (Multiplex Tilt and Telescopic ECU) NG --> See step 7 OK: Go to next step
5. CHECK TILT AND TELESCOPIC SWITCH Remove the tilt and telescopic switch. Refer to «REMOVAL»(ref-398268-S21056765382011051600000) . Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Switch Condition Specified Condition 1 - 3 Tilt up 342 to 378 ohms Tilt down 1890.5 to 2089.5 ohms Telescopic contract 750.5 to 829.5 ohms Telescopic extend 152 to 168 ohms TEXT IN ILLUSTRATION *1 Component without harness connected (Tilt and Telescopic Switch) NG --> See step 8 OK --> See step 9
6. USE SIMULATION METHOD TO CHECK. Refer to «HOW TO PROCEED WITH TROUBLESHOOTING»(ref-398089-S18270818032011051600000)
7. REPLACE MULTIPLEX TILT AND TELESCOPIC ECU. Refer to «REMOVAL»(ref-398268-S10748883272011051600000)
8. REPLACE TILT AND TELESCOPIC SWITCH. Refer to «REMOVAL»(ref-398268-S21056765382011051600000)
9. REPLACE HEADLIGHT DIMMER SWITCH ASSEMBLY. Refer to «REMOVAL»(ref-398250-S32594437292011051600000)

The tilt motor is operated by the power source voltage supplied from the multiplex tilt and telescopic ECU and makes the steering column tilt up and down. The tilt position sensor (Hall IC) in the tilt motor detects the tilt angle of the steering column and outputs a signal to the multiplex tilt and telescopic ECU based on that angle.

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HINT

Limit positions can be confirmed on the Techstream.

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The telescopic motor is operated by the power source voltage supplied from the multiplex tilt and telescopic ECU and slides the steering column forward and backward. The telescopic position sensor (Hall IC) in the telescopic motor detects the sliding position in the forward and backward directions of the steering column and outputs a signal to the multiplex tilt and telescopic ECU based on that sliding amount.

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HINT

Limit positions can be confirmed on the Techstream.

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The ECU power source circuit supplies positive (+) voltage to the multiplex tilt and telescopic ECU.

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The multiplex tilt and telescopic ECU forms a network with the ECUs of other systems through the CAN communication bus. Each ECU informs the other ECUs that it is connected to the network by outputting a specified signal (periodic signal) onto the CAN communication bus on a regular schedule. The multiplex tilt and telescopic ECU detects the connection of each ECU based on the signal.

The multiplex tilt and telescopic ECU forms a network with the ECUs of other systems through the CAN communication bus. Each ECU informs the other ECUs that it is connected to the network by outputting a specified signal (periodic signal) onto the communication bus on a regular basis. The multiplex tilt and telescopic ECU receives vehicle speed signals from the combination meter via the CAN communication bus to prevent improper operation of the auto away/return function during driving.

HINT

*: If the power switch is turned off immediately after the vehicle comes to a sudden stop, the last vehicle speed signal may not be 0 km/h (0 mph).

This is the power source for the power tilt and power telescopic steering column system.

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The signals generated by operating the manual switch are sent to the multiplex tilt and telescopic ECU through the communication bus.

When the power switch is turned on (IG), the IG power source circuit supplies positive (+) voltage to the multiplex tilt and telescopic ECU.

The multiplex tilt and telescopic ECU also receives power switch signals via this circuit.

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