Easy one-page printout for the garage or repair shop
This summary uses the existing diagnostic information shown in full below.
This code means there's a problem with the sensor that checks the pressure of the transmission fluid. It's like a thermometer for the car's transmission, and it's saying the temperature is way too high.
The P0878 code is triggered when the transmission control module (TCM) detects a high voltage signal from the transmission fluid pressure sensor/switch D, indicating a possible high pressure condition.
The transmission fluid pressure sensor/switch D monitors the hydraulic pressure inside the transmission. If the sensor sends a voltage signal that is higher than expected, the TCM interprets this as a high pressure condition and sets the P0878 code. This could be due to a faulty sensor, wiring issues, or a malfunctioning transmission control module.
• Check Engine Light illuminated
• Transmission slipping or not shifting properly
• Decreased fuel efficiency
• Faulty transmission fluid pressure sensor/switch
• Wiring issues or poor electrical connections
• Malfunctioning transmission control module (TCM)
Transmission Control Module (TCM): A computer that controls the operation of the transmission.
OBD-II Scanner: A tool used to read diagnostic trouble codes from a vehicle's computer.
• Use an OBD-II scanner to confirm the P0878 code.
• Inspect the wiring and connectors for damage or corrosion.
• Test the transmission fluid pressure sensor with a multimeter.
• Replace the transmission fluid pressure sensor/switch if faulty.
• Repair or replace damaged wiring or connectors.
• Reprogram or replace the transmission control module if necessary.
• OBD-II scanner
• Multimeter
• Basic hand tools
$150 - $400
Moderate
• Ford F-150
• Chevrolet Silverado
• Honda Accord
• Regular transmission fluid checks and changes
• Routine vehicle maintenance
• Inspect wiring and connectors periodically
Sensor Issue
• Avoid driving the vehicle aggressively until the issue is resolved.
• Consult a professional mechanic for a thorough diagnosis.
Check with your vehicle manufacturer for specific warranty coverage related to transmission components.
P0878 has been a common issue in vehicles with automatic transmissions, especially as they age and components wear out.
Moderate – It's important to address this issue soon to prevent further transmission damage.
Driving with a faulty transmission can be dangerous and may lead to further damage. It's recommended to have the vehicle inspected and repaired by a professional.
• Vehicle at operating temperature
• Transmission in drive
The transmission fluid pressure sensor is typically located on the transmission housing.
Q: Can I drive with a P0878 code?
A: It's not recommended to drive for long periods with this code as it may lead to further transmission damage.
Q: How do I reset the P0878 code?
A: The code can be cleared with an OBD-II scanner, but it's important to fix the underlying issue first.
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