Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Circuit Description
This DTC is output when failure of the jam protection limit switch circuit is detected.
The jam protection limit switch is built in the power window motor.
This switch is OFF when the window stays between the fully closed position and 4 mm under the full-closed position, and Rear LH Door ECU reads this signal.
| DTC No. | DTC Detecting Condition | Trouble Area |
|---|---|---|
| B1237 | No change in limit switch more than 2.0 seconds even if operating glass down when limit switch is OFF (window glass is fully closed) |
|
HINT:
When the door ECU detects the condition that the power window is lowered to turn the limit switch from OFF to ON, this DTC is cleared.
NO RELATED
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
Affiliate disclosure: We may earn a commission at no extra cost to you.
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.