Understanding TPMS Relearn on LX Vehicles
LX vehicles (including models like the LX 570, LX 600, and older LX 470) use a direct TPMS system that monitors tire pressure via sensors mounted inside each wheel. When you replace a sensor, rotate tires, or swap seasonal wheels, the vehicle’s ECU needs to “relearn” which sensor is in which position. Without a proper relearn, the TPMS warning light stays on, and pressure readings become inaccurate.
The BH-Sens BL-ST-038 sensor (SKU: BL-ST-038) is pre-programmed to LX-specific OE frequencies (433MHz) and OE numbers 802000121AA, 802000126AA, and F02361701001AA. This means no sensor programming is needed—only a relearn procedure to pair the sensor to the vehicle.
Three Relearn Methods for LX
LX vehicles support three relearn methods. Choose based on your tools and preference.
1. Auto Relearn (Driving Method)
This is the simplest method—no tools required. It works on most LX models from 2010 onward, but some earlier models may require a stationary or OBD method.
Procedure:
- Ensure all tires are inflated to the recommended pressure (check driver door placard).
- Start the engine and drive the vehicle above 50 km/h (30 mph) for 10-15 minutes continuously.
- The system automatically detects the sensors and assigns positions based on signal strength and wheel rotation.
- After driving, the TPMS light should turn off. If it remains on, try a second drive cycle.
Limitations: Some LX models (especially 2016+ with advanced TPMS) may require the OBD method if the auto relearn fails after two attempts.
2. OBD Relearn (Using a TPMS Tool)
For LX vehicles with direct TPMS, an OBD relearn is the most reliable method. You’ll need a compatible TPMS tool (e.g., Autel TS508, ATEQ VT56, or Bartec Tech400).
Procedure:
- Connect the TPMS tool to the vehicle’s OBD-II port (usually under the dashboard on the driver’s side).
- Select the correct vehicle model: Lexus > LX > model year.
- The tool will display a menu—choose “Relearn” or “Sensor ID Registration.”
- Follow the tool’s prompts to trigger each sensor (typically a low-frequency trigger at each valve stem).
- The tool sends the sensor IDs to the ECU, completing the relearn in under 5 minutes.
Important: The BL-ST-038 sensor is pre-programmed, so the OBD tool only needs to read the sensor ID and register it—no programming is required.
3. Stationary Relearn (Magnet Method)
Some LX models (particularly 2007-2012) support a stationary relearn using a strong magnet. This method does not require a scan tool.
Procedure:
- Locate the TPMS reset button (usually under the steering wheel or in the glove box). Check your owner’s manual if unsure.
- Turn the ignition to ON (do not start the engine).
- Press and hold the TPMS reset button until the tire pressure warning light blinks three times (about 3 seconds).
- Release the button. The system enters learning mode.
- Starting with the left front tire, hold a TPMS magnet (or a strong neodymium magnet) against the valve stem for 5-10 seconds. The horn will chirp once to confirm.
- Repeat for the right front, right rear, and left rear tires in that order.
- After the last tire, the horn chirps twice—relearn complete. Turn off the ignition.
Note: This method only works if the sensors are already compatible (433MHz) and the vehicle’s system is in learning mode.
When to Use Each Method
| Method | Best For | Tools Needed | Time | Reliability |
|---|---|---|---|---|
| Auto Relearn | Quick sensor swap, no tools | None | 15-20 min drive | Moderate (may fail on some models) |
| OBD Relearn | All LX models, guaranteed success | TPMS tool | 5-10 min | High |
| Stationary Relearn | Older LX models (pre-2013) | Strong magnet | 5-10 min | High (if supported) |
Common Mistakes to Avoid
- Skipping the relearn: Even if the BL-ST-038 sensor is pre-programmed, the ECU must pair with it. Driving without relearning may keep the warning light on.
- Using the wrong magnet: A weak fridge magnet won’t work. Use a dedicated TPMS magnet (rated 5,000+ Gauss) or a neodymium magnet.
- Forgetting tire pressure: Ensure all tires are at the correct pressure before starting any relearn—low pressure can cause false triggers.
Recommended Part
For LX vehicles requiring a 433MHz TPMS sensor, the BL-ST-038 | BH-Sens 433MHz TPMS Tire Pressure Sensor | Fits Chery, Chery Ev, Cowin, Exeed | OE# 802000121AA, 802000126AA, F02361701001AA is a direct OE-fit replacement (OE# 802000121AA, 802000126AA, F02361701001AA). It’s clamp-in, pre-programmed, and compatible with Chery, Chery EV, Cowin, and Exeed models as well. After installation, use one of the relearn methods above—no additional programming needed.
FAQ
How do I know if my LX requires an OBD relearn or auto relearn?
Check your owner’s manual for the TPMS section. Most 2010-2015 LX models support auto relearn (drive method). 2016+ models with direct TPMS often require an OBD relearn. If the auto relearn fails after two drive cycles, switch to OBD.
Can I use the BL-ST-038 sensor on a 2008 Lexus LX 570?
Yes, the BL-ST-038 is compatible with LX 570 models (2008-2021) as long as your vehicle uses 433MHz sensors. Verify by checking the OE number on your old sensor—if it matches 802000121AA, 802000126AA, or F02361701001AA, the BL-ST-038 is a direct fit.
What if my LX doesn’t have a TPMS reset button?
If there’s no reset button under the steering wheel or in the glove box, your model likely uses a drive-cycle auto relearn or requires an OBD tool. The stationary magnet method won’t work without the reset button.
How often should I replace TPMS sensors on my LX?
TPMS sensors typically last 5-10 years due to battery life. If you notice the warning light staying on after a relearn, or if the pressure readings are erratic, the sensor battery may be dead. Replace with a pre-programmed sensor like the BL-ST-038 to avoid programming fees.