2012 Lexus IS 250 Base, AWDFACTORY OEM SERVICE PROCEDURE

Problem Symptoms Table

Inspect the suspected areas in numerical order by referring to the corresponding pages when any of the following symptoms occurs:

STEERING LOCK FUNCTION

Symptom Suspected Area Refer to
Steering wheel cannot be unlocked (the engine cannot be started). 1. Initialization Refer to INITIALIZATION 
2. Check for DTCs in the push button start. (for 2GR-FSE) Refer to DTC CHECK / CLEAR
3. Check for DTCs in the push button start. (for 4GR-FSE) Refer to DTC CHECK / CLEAR
4. Check for DTCs in the engine immobiliser system. Refer to DTC CHECK / CLEAR
5. Check that the Lock/Unlock Receive item in the DATA LIST of the certification ECU displays YES within 10 seconds after starting the engine. (If it displays NO, see No steering unlock command in this table.) Refer to DATA LIST / ACTIVE TEST 
6. Check the output from the IGE terminal of the steering lock ECU. Refer to Steering Lock Motor Drive Power Circuit
7. Steering lock ECU power source circuit. Refer to Power Source Circuit
8. Replace the steering lock ECU. (for Manual Tilt) Refer to DISASSEMBLY
9. Replace the steering lock ECU. (for Power Tilt and Power Telescopic Steering) Refer to DISASSEMBLY
Steering wheel cannot be unlocked (no steering unlock command). 1. Check that the S Code Check item in the DATA LIST of the certification ECU displays OK. (If it displays NG, replace the ID code box.) Refer to DATA LIST / ACTIVE TEST 
2. Check that the L Code Check item in the DATA LIST of the certification ECU displays OK. (If it displays NG, replace the ID code box.) Refer to DATA LIST / ACTIVE TEST 
3. Replace the certification ECU. -
Steering wheel cannot be locked. 1. Check for DTCs in the push button start. (for 2GR-FSE) Refer to DTC CHECK / CLEAR
2. Check for DTCs in the push button start. (for 4GR-FSE) Refer to DTC CHECK / CLEAR
3. Check for DTCs in the engine immobiliser system. Refer to DTC CHECK / CLEAR
4. With the engine switch off and the shift in the P position, open and close the drivers door. After that, check that the Lock/Unlock Receive item in the DATA LIST of the certification ECU displays YES within 10 seconds. (If it displays NO, see No steering lock command in this table.) Refer to DATA LIST / ACTIVE TEST 
5. Check the output from the IGE terminal of the steering lock ECU. Refer to Steering Lock Motor Drive Power Circuit
6. Steering lock ECU power source circuit. Refer to Power Source Circuit
7. Replace the steering lock ECU. (for Manual Tilt) Refer to DISASSEMBLY
8. Replace the steering lock ECU. (for Power Tilt and Power Telescopic) Refer to DISASSEMBLY
Steering wheel cannot be locked (no steering lock command). 1. Courtesy light switch circuit Refer to Door Courtesy Switch Circuit
2. Check that the S Code Check item in the DATA LIST of the certification ECU displays OK. (If it displays NG, replace the ID code box.) Refer to DATA LIST / ACTIVE TEST 
3. Check that the L Code Check item in the DATA LIST of the certification ECU displays OK. (If it displays NG, replace the ID code box.) Refer to DATA LIST / ACTIVE TEST 
4. Replace the certification ECU. -
PUSH BUTTON START FUNCTION

Symptom Suspected Area Refer to
Engine does not start. 1. Initialization Refer to INITIALIZATION 
2. Check for DTCs in the push button start. (for 2GR-FSE) Refer to DTC CHECK / CLEAR
3. Check for DTCs in the push button start. (for 4GR-FSE) Refer to DTC CHECK / CLEAR
4. Check for DTCs in the engine immobiliser system. Refer to DTC CHECK / CLEAR
5. Check that the engine switch is turned on. -
6. Check cranking operation. (If cranking operation is possible, see Engine does not start due to the engine immobilizer in this table.) -
7. Check Shift P Sig in the DATA LIST of the power source control ECU and confirm that the shift signal is normal. -
8. Check whether the steering wheel is locked or unlocked. (If it is locked, see Steering wheel cannot be unlocked in the steering lock function table.) -
9. Check the output from the SLP terminal of the steering lock ECU. Refer to Unlock Position Sensor Signal Circuit
10. Check the output signal from the ST SW of the certification ECU (DTC B2275). (for 2GR-FSE) Refer to DTC B2275: STSW Monitor Malfunction
11. Check the output signal from the ST SW of the certification ECU (DTC B2275). (for 4GR-FSE) Refer to DTC B2275: STSW Monitor Malfunction
12. Replace the power source control ECU. -
Engine does not start due to the engine immobilizer. 1. Check that the L Code Check item in the DATA LIST of the certification ECU displays OK. (If it displays NG, replace the ID code box.) Refer to DATA LIST / ACTIVE TEST 
2. Check that the Engine Start Request item in the DATA LIST of the certification ECU displays YES. (If it displays NO, replace the certification ECU.) Refer to DATA LIST / ACTIVE TEST 
3. Check that the S Code Check item in the DATA LIST of the certification ECU displays OK. (If it displays NG, replace the ID code box.) Refer to DATA LIST / ACTIVE TEST 
4. Replace the ID code box. -
Chapter Navigation
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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • • You smell fuel, burning insulation, or see smoke.
  • • Brakes feel soft, pull hard to one side, or make grinding noises.
  • • The engine overheats, stalls repeatedly, or misfires under load.
  • • You are missing required tools, torque specs, or safe lifting equipment.
  • • You are not confident in the next step or safety outcome.