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 has detected a problem with the gear shifter. It's like when your video game controller isn't working right, and your character won't move the way you want.
The P1866 code is triggered when the transmission control module (TCM) detects a high voltage signal from the Gear Selector Lever 2 (GSL2) circuit.
The Gear Selector Lever (GSL2) circuit is responsible for communicating the position of the gear shifter to the transmission control module. A 'high' circuit condition indicates that the voltage level is above the expected range, which could be due to a short circuit or a faulty sensor.
• Check Engine Light is on
• Transmission may not shift properly
• Vehicle may not move or engage gears
• Faulty gear selector lever
• Short circuit in the wiring
• Defective transmission control module (TCM)
Transmission Control Module (TCM): A computer that controls the transmission's operation.
Gear Selector Lever: The lever used to select the gear of the vehicle.
• Check for any other related codes and address those first.
• Inspect the wiring and connectors for damage or corrosion.
• Test the gear selector lever for proper operation.
• Repair or replace damaged wiring or connectors.
• Replace the gear selector lever if faulty.
• Replace or reprogram the transmission control module if necessary.
• OBD-II scanner
• Multimeter
• Screwdriver set
$150 - $500
Moderate
• Ford Explorer
• Chevrolet Silverado
• Toyota Camry
• Regularly inspect and maintain transmission components.
• Ensure proper electrical connections.
• Avoid harsh shifting or driving habits.
Sensor Issue
• Have your vehicle inspected by a professional mechanic.
• Avoid driving if the vehicle is not shifting properly.
Check your vehicle's warranty for coverage on transmission components.
This code has been associated with transmission issues in older vehicles, often due to wear and tear or electrical faults.
Moderate – It is advisable to address this issue soon to prevent further transmission damage.
Driving with a malfunctioning transmission can be dangerous. Ensure repairs are completed by a qualified technician.
• Vehicle must be running.
• Gear selector lever must be operated through all positions.
The gear selector lever is located in the center console or on the steering column, depending on the vehicle model.
Q: Can I drive with code P1866?
A: It's not recommended to drive with this code active as it may lead to transmission issues.
Q: How do I clear a P1866 code?
A: After repairs, use an OBD-II scanner to clear the code from the vehicle's computer.
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