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 there's a problem with the sensor that checks how hard the fluid is being pushed around in the transmission. It's like when you have a garden hose and the water isn't coming out as strong as it should.
The P0871 code is triggered when the transmission control module (TCM) detects a problem with the transmission fluid pressure sensor or switch circuit, specifically sensor/switch C.
The transmission fluid pressure sensor/switch C is responsible for monitoring the hydraulic pressure inside the transmission. This sensor provides feedback to the TCM, which uses this data to control the transmission's shifting patterns. If the sensor's readings are outside the expected range, the P0871 code is set.
• Check Engine Light is on
• Transmission shifting issues
• Poor fuel economy
• Transmission overheating
• Vehicle may go into limp mode
• Faulty transmission fluid pressure sensor
• Wiring issues such as open or shorted wires
• Poor electrical connection at the sensor
• Faulty transmission control module (TCM)
• Low transmission fluid level
Transmission Control Module (TCM): A computer that controls the transmission's functions.
Hydraulic Pressure: The force exerted by the transmission fluid to enable shifting.
• Check the transmission fluid level and condition.
• Inspect the wiring and connectors to the transmission fluid pressure sensor.
• Test the sensor for proper operation using a multimeter.
• Check for any other related trouble codes.
• If necessary, test the TCM for faults.
• Replace the faulty transmission fluid pressure sensor.
• Repair or replace damaged wiring or connectors.
• Replace the transmission control module if faulty.
• Replenish or change the transmission fluid.
• OBD-II scanner
• Multimeter
• Basic hand tools
• Transmission fluid
$150 - $400
Moderate
• Ford F-150
• Chevrolet Silverado
• Dodge Ram
• Regularly check and maintain transmission fluid levels.
• Have the transmission serviced at recommended intervals.
• Address Check Engine Light warnings promptly.
Sensor Issue
• Do not ignore the Check Engine Light.
• Have the vehicle inspected by a professional if you notice transmission issues.
• Regular maintenance can help prevent this code from appearing.
Transmission components may be covered under powertrain warranty. Check with the vehicle manufacturer.
This code has been associated with transmission issues in various vehicles, particularly those with high mileage or poor maintenance history.
Moderate – Addressing this code promptly can prevent further transmission damage.
Driving with a malfunctioning transmission can be unsafe. Address this issue to ensure vehicle safety.
• Vehicle at operating temperature
• Transmission engaged in drive
The transmission fluid pressure sensor is typically located on the transmission housing.
Q: Can I drive with a P0871 code?
A: It's not recommended to drive for long with this code, as it can lead to transmission damage.
Q: How do I reset the P0871 code?
A: After repairs, the code can be reset with an OBD-II scanner. However, ensure the issue is fixed first.
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