Lexus IS250 IS220d GSE20 ALE20 - STEERING COLUMN
ELECTRIC STEERING LOCK - DIAGNOSIS SYSTEM
| DESCRIPTION |
DIAGNOSTIC SYSTEM
When troubleshooting a vehicle with a diagnostic system, the only difference from the usual troubleshooting procedure is connecting the intelligent tester to the vehicle and reading various data output from the vehicle's steering lock ECU.
The steering lock ECU records DTCs when the computer detects a malfunction in the computer itself or in its circuits.
To check the DTCs, connect the intelligent tester to the DLC3 on the vehicle. The intelligent tester enables the DTCs to be cleared, the indicators to be activated, and the DATA LIST to be checked.
The diagnosis information of the steering lock ECU is transmitted to the tester via the certification ECU as the steering lock ECU is not connected to BEAN.
Check the DLC3.
The certification ECU follows ISO 15765-04 for its communication protocol. The terminal arrangement of the DLC3 complies with ISO 15031-03 and matches the ISO 15765-04 format.
| Symbols (Terminals No.) | Terminal Description | Condition | Specified Condition |
| SIL (7) - SG (5) | Bus "+" line | During communication | Pulse generation |
| CG (4) - Body ground | Chassis ground | Always | Below 1 Ω |
| SG (5) - Body ground | Signal ground | Always | Below 1 Ω |
| BAT (16) - Body ground | Battery positive | Always | 11 to 14 V |
- HINT:
- If the display shows a communication error message after connecting the intelligent tester cable to the DLC3 and turning the engine switch on (IG), there is a problem with either the vehicle or tester.
| WARNING FUNCTION OF ENGINE SWITCH INDICATOR |
The steering lock ECU blinks the LED indicator of the engine switch when any of the following problems occurs in the system:
| Detection Item | Indicator Light Blink Pattern | Indication Status | Countermeasure |
| Steering lock is still not released | Blinks green at 1-second intervals Goes off 15 seconds after blinking starts | The motor operates to release the steering lock, but the steering lock cannot be released (e.g. the lock bar is stuck in the steering column). | Push the engine switch while turning the steering wheel left or right. |
| Malfunction in push start system | Blinks amber at 2-second intervals Goes off 15 seconds after the engine switch is turned off while blinking | There is a short in the devices activating the motor. There is a problem in the steering lock ECU or power source control ECU. | Troubleshoot by following "HOW TO PROCEED WITH TROUBLESHOOTING" . |
| WARNING FUNCTION OF COMBINATION METER |
The steering lock ECU displays a warning on the combination meter when any of the following problems occurs in the system.
| Detection Item | Display | Indication Status | Countermeasure |
| Steering lock is still not released | "S/T is not Unlocked" Goes off 15 seconds after blinking starts | The motor operates to release the steering lock, but the steering lock cannot be released (e.g. the lock bar is stuck in the steering column). | Push the engine switch while turning the steering wheel left or right. |
| Malfunction in push start system | "Check S/T Lock" Goes off 15 seconds after the engine switch is turned off while blinking | There is a short in the devices activating the motor. There is a problem in the steering lock ECU or power source control ECU. | Troubleshoot by following "HOW TO PROCEED WITH TROUBLESHOOTING" . |