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 is having trouble reading a sensor that helps it know which gear you're trying to select.
The gate select sensor is part of the transmission system and helps the vehicle's computer understand which gear is being selected. A 'circuit low' condition indicates that the sensor is not sending enough voltage to the computer.
P1851 is triggered when the Powertrain Control Module (PCM) detects a lower than expected voltage from the gate select sensor circuit. This sensor is crucial for the proper operation of the gear selection mechanism in the transmission.
• Check Engine Light is on
• Difficulty in shifting gears
• Transmission may go into limp mode
• Faulty gate select sensor
• Damaged wiring or connectors
• Faulty PCM
PCM: Powertrain Control Module
OBD-II: On-Board Diagnostics II
• Use an OBD-II scanner to confirm the code
• Inspect the wiring and connectors for damage
• Test the gate select sensor for proper operation
• Replace the gate select sensor if faulty
• Repair or replace damaged wiring or connectors
• Reprogram or replace the PCM if necessary
• OBD-II scanner
• Multimeter
• Basic hand tools
$150 - $500
Moderate
• Ford Focus
• Volkswagen Jetta
• Audi A4
• Regular maintenance of transmission system
• Ensure wiring and connectors are in good condition
• Avoid harsh driving conditions
Sensor Issue
• Avoid driving until the issue is resolved to prevent further damage
• Consult a professional mechanic for accurate diagnosis
Check with the vehicle manufacturer for specific warranty coverage related to the transmission system.
This code has been associated with sensor issues in various vehicles with electronic transmission control systems.
Moderate – Should be addressed soon to prevent transmission damage.
Driving with a malfunctioning transmission sensor can lead to unsafe driving conditions.
• Vehicle in park or neutral
• Engine running
The gate select sensor is typically located on or near the transmission assembly.
Q: Can I drive with a P1851 code?
A: It's not recommended as it may cause further damage to the transmission.
Q: How do I reset the P1851 code?
A: After repairs, use an OBD-II scanner to clear the code. If the issue is fixed, it should not return.
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