P0874
UniversalTransmission Fluid Pressure Sensor/Switch C Circuit Intermittent
Medium SeverityThis code indicates that the Powertrain Control Module (PCM) has detected an intermittent electrical issue within the circuit for the Transmission Fluid Pressure Sensor/Switch C. This intermittent signal can cause unpredictable transmission behavior, leading to erratic shifts or delayed engagement, and may illuminate the Check Engine Light.
⚠️ Before You Begin (Safety First)
Always use appropriate safety gear, including gloves and eye protection, when working on a vehicle. Ensure the vehicle is securely supported on jack stands if working underneath. Disconnect the battery before performing any electrical repairs to prevent accidental shorts or injury.
Common Symptoms
- Check Engine Light illumination
- Harsh or erratic transmission shifts
- Delayed transmission engagement
- Transmission may enter 'limp mode'
- Poor fuel economy
Common Causes
- Loose or corroded electrical connector at the Transmission Fluid Pressure Sensor/Switch C
- Damaged or chafed wiring in the sensor circuit
- Faulty or intermittently failing Transmission Fluid Pressure Sensor/Switch C
- Internal transmission issues affecting pressure readings (less common for intermittent circuit code)
- Faulty Powertrain Control Module (PCM) (rare)
Frequently reported on: 2008-2015 Dodge Grand Caravan, 2007-2014 Chrysler 300, 2011-2018 Ford F-150, 2007-2013 Chevrolet Silverado 1500
Diagnostic Steps
- Locate the Transmission Fluid Pressure Sensor/Switch C, typically on or inside the transmission case. Refer to your vehicle's service manual for the exact location.
- Visually inspect the wiring harness and electrical connector for the sensor for any signs of damage, fraying, corrosion, or looseness. Ensure the connector is fully seated.
- If accessible, carefully disconnect and reconnect the sensor's electrical connector to ensure a solid contact.
- Clear the P0874 code using an OBD-II scanner. Test drive the vehicle under various conditions (stop-and-go, highway) to see if the code returns or if symptoms persist.
- If the code returns, consider testing the sensor's resistance and voltage readings with a multimeter, comparing them to manufacturer specifications. If values are out of spec or intermittent, replace the sensor.
👨🔧 When to Call a Professional
Due to the intermittent nature of this fault and the complexity of transmission diagnostics, it is highly recommended to seek professional assistance if basic visual inspections and code clearing do not resolve the issue. An experienced technician can perform advanced electrical diagnosis and pinpoint the precise cause of the intermittency within the circuit or sensor itself, especially if transmission performance issues are significant.
Commonly Asked Questions
What does 'intermittent' mean for P0874?
Intermittent means the fault is not constant; the sensor circuit works sometimes and fails at other times, making it harder to diagnose than a continuous fault.
Can I drive my car with a P0874 code?
While you might be able to drive, it's not recommended for long. Intermittent transmission issues can lead to unpredictable behavior, potential damage to the transmission, and compromise safety. It's best to address it promptly.
Where is the Transmission Fluid Pressure Sensor/Switch C located?
Its location varies by vehicle, but it's typically found on the valve body inside the transmission or externally mounted on the transmission case. Consult your vehicle's service manual for the precise location.
Is P0874 an expensive repair?
The cost can vary. If it's a simple loose connection or a faulty sensor, it might be relatively inexpensive. However, if the issue is deeper within the transmission or requires extensive diagnostic time, costs can increase significantly.
What tools do I need to diagnose P0874?
At a minimum, you'll need an OBD-II scanner to read and clear codes. A multimeter is essential for testing electrical continuity and voltage. A vehicle-specific service manual is also highly recommended for wiring diagrams and sensor specifications.