Easy one-page printout for the garage or repair shop
This summary uses the existing diagnostic information shown in full below.
This code means that the car's computer thinks the sensor that tells how fast the car's wheels are turning is giving a signal that's too high.
The output shaft speed sensor measures the rotational speed of the transmission's output shaft. If the signal from this sensor is higher than expected, the P1812 code is triggered.
P1812 indicates that the transmission control module (TCM) has detected an unusually high voltage signal from the output shaft speed sensor circuit. This could be due to a faulty sensor, wiring issues, or a problem with the TCM itself.
• Erratic or harsh shifting
• Transmission slipping
• Illuminated check engine light
• Faulty output shaft speed sensor
• Wiring issues such as shorts or open circuits
• Malfunctioning transmission control module (TCM)
OBD-II: On-Board Diagnostics, a standardized system for vehicle self-diagnosis and reporting.
TCM: Transmission Control Module, the computer that controls the transmission.
• Use an OBD-II scanner to confirm the code.
• Inspect the wiring and connectors for damage or corrosion.
• Test the output shaft speed sensor for proper operation.
• Replace the output shaft speed sensor if faulty.
• Repair or replace damaged wiring or connectors.
• Reprogram or replace the TCM if necessary.
• OBD-II scanner
• Multimeter
• Wrench set
$100 - $400
Moderate
• Ford F-150
• Chevrolet Silverado
• Toyota Camry
• Regularly inspect and maintain transmission components.
• Ensure wiring and connectors are free from corrosion.
• Perform periodic transmission fluid changes.
Sensor Issue
• Avoid driving aggressively until the issue is resolved.
• Consult a professional mechanic if unsure about the repair.
Check with your vehicle manufacturer for warranty coverage on transmission components.
P1812 has been a common code in vehicles with automatic transmissions, often related to sensor or wiring issues.
Moderate – While the vehicle may still be drivable, addressing this issue promptly can prevent further transmission damage.
Driving with a malfunctioning transmission can be unsafe and lead to further vehicle damage.
• Vehicle at operating temperature
• Transmission in gear
The output shaft speed sensor is typically located on the transmission, near the output shaft.
Q: Can I drive with a P1812 code?
A: It's possible, but not recommended as it may cause further transmission damage.
Q: How do I reset the P1812 code?
A: After addressing the underlying issue, use an OBD-II scanner to clear the code.
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