Steering Column (Service Information): Diagnosis Lexus GS IV

INSPECTION [03/2012 - ]

1. INSPECT STEERING COLUMN ASSEMBLY Inspect the tilt motor. Disconnect the tilt motor connector. Apply 12 V auxiliary battery voltage to the tilt motor connector. Then check the steering wheel tilt operation. OK Measurement Condition Specified Condition 12 V auxiliary battery positive (+) lead --> Terminal 1 (TIM+) 12 V auxiliary battery negative (-) lead --> Terminal 2 (TIM-) The steering wheel tilts up. 12 V auxiliary battery negative (-) lead --> Terminal 1 (TIM+) 12 V auxiliary battery positive (+) lead --> Terminal 2 (TIM-) The steering wheel tilts down. TEXT IN ILLUSTRATION *a Component without harness connected (Tilt Motor) If the result is not as specified, replace the steering column assembly. Inspect the telescopic motor. Disconnect the telescopic motor connector. Apply 12 V auxiliary battery voltage to the telescopic motor connector. Then check the steering column telescopic operation. OK Measurement Condition Specified Condition 12 V auxiliary battery positive (+) lead --> Terminal 2 (TEM+) 12 V auxiliary battery negative (-) lead --> Terminal 1 (TEM-) The steering column contracts. 12 V auxiliary battery positive (+) lead --> Terminal 1 (TEM-) 12 V auxiliary battery negative (-) lead --> Terminal 2 (TEM+) The steering column extends. TEXT IN ILLUSTRATION *a Component without harness connected (Telescopic Motor) If the result is not as specified, replace the steering column assembly.

Scheme 14

1. INSPECT STEERING PAD SWITCH ASSEMBLY Inspect the pad switch. Measure the resistance according to the value(s) in the table below. TEXT IN ILLUSTRATION *1 Seek+ Switch *2 Seek- Switch *3 Volume+ Switch *4 Volume- Switch *5 MODE Switch *6 Lane Keeping Assist Switch *7 Voice Switch *8 Return Switch *9 Off Hook Switch *10 On Hook Switch *11 DISP Switch *12 Distance Control Switch *a Component without harness connected (Steering Pad Switch Assembly) - - Standard Resistance Tester Connection Switch Condition Specified Condition A11 (AU1) - A8 (EAU) No switch pushed 95 to 105 kohms Seek+ switch pushed Below 2.5 ohms Seek- switch pushed 313 to 345 ohms Volume+ switch pushed 950 to 1050 ohms Volume- switch pushed 2955 to 3265 ohms A10 (AU2) - A8 (EAU) No switch pushed 95 to 105 kohms MODE switch pushed Below 2.5 ohms Return Switch pushed 313 to 345 ohms On hook switch pushed 313 to 345 ohms Off hook switch pushed 950 to 1050 ohms Voice switch pushed 2955 to 3265 ohms A2 (+DP) - A3 (-DP) No switch pushed 1 Mohms DISP switch pushed Below 2.5 ohms A4 (DIST) - A7 (ECC) No switch pushed 1 Mohms Distance control switch pushed Below 2.5 ohms Lane Keeping Assist Switch pushed 228 to 252 ohms A1 (HO) - C (HO) Always Below 1 ohms A6 (SUP) - B1 (SUP) Always Below 1 ohms A12 (SDN) - B2 (SDN) Always Below 1 ohms A7 (ECC) - B3 (ECC) Always Below 1 ohms If the result is not as specified, replace the steering pad switch assembly. Check the illumination. Connect the auxiliary battery positive (+) lead to terminal A5 (IL+2) and the negative (-) lead to terminal A3 (-DP) of the steering pad switch assembly connector. Check that the switch illumination comes on. OK Steering pad switch illumination comes on. If the result is not as specified, replace the steering pad switch assembly.

1. INSPECT TILT AND TELESCOPIC SWITCH Measure the resistance according to the value(s) in the table below. TEXT IN ILLUSTRATION *a Component without harness connected (Tilt and Telescopic Switch) Standard Resistance Tester Connection Switch Condition Specified Condition 1 - 3 Telescopic contract 750.5 to 829.5 ohms Telescopic extend 152 to 168 ohms Tilt up 342 to 378 ohms Tilt down 1890.5 to 2089.5 ohms If the result is not as specified, replace the tilt and telescopic switch.

1. INSPECT INTEGRATION CONTROL AND PANEL ASSEMBLY (STEERING HEATER SWITCH) Disconnect the steering heater switch connector. TEXT IN ILLUSTRATION *a Component without harness connected (Steering Heater Switch) Measure the voltage according to the value(s) in the table below. HINT: As the circuit has a diode, perform the measurement in diode test mode, and do not mistake the polarity. Standard Voltage Tester Connection (Positive (+) tester probe - Negative (-) tester probe) Condition Specified Condition 1 (B) - 10 (+) Always Below 1.25 V 9 (IN) - 10 (+) Steering heater switch is pushed Below 1.25 V Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition 1 (B) - 9 (IN) Steering heater switch is pushed Below 1 ohms 1 (B) - 9 (IN) Steering heater switch is not pushed 10 kohms or higher