P0840
Transmission Fluid Pressure Sensor/Switch A Circuit
P0840 is an OBD-II diagnostic trouble code meaning: Transmission Fluid Pressure Sensor/Switch A Circuit. Common causes: transmission fluid pressure sensor malfunction, open or short circuit in the sensor circuit. Estimated repair cost: $17–56.
Symptoms
- Incorrect gear shifting
- Enabling transmission emergency mode
- Check Engine light comes on
- Reduced transmission efficiency
- Acceleration problems
Causes
- Transmission fluid pressure sensor malfunction
- Open or short circuit in the sensor circuit
- Poor contact in the sensor connector
- Low or contaminated transmission fluid
- Mechanical problems in the transmission hydraulic system
How to Fix
- Check the level and condition of the transmission fluid
- Inspect the connectors and wiring of the sensor
- Check resistance and sensor signal
- Replace transmission fluid pressure sensor if necessary
- Check the transmission hydraulic system
Related codes
Error P0840 by Vehicle Brand
FAQ
What does the P0840 code mean?
P0840 is an OBD-II diagnostic trouble code that indicates: Transmission Fluid Pressure Sensor/Switch A Circuit
What causes a P0840 error code?
The most common causes of P0840 include: Transmission fluid pressure sensor malfunction; Open or short circuit in the sensor circuit; Poor contact in the sensor connector; Low or contaminated transmission fluid.
How do I fix a P0840 diagnostic trouble code?
To fix P0840: Check the level and condition of the transmission fluid. Inspect the connectors and wiring of the sensor. Check resistance and sensor signal. For a complete diagnosis, use an OBD-II scanner.
Is it safe to drive with P0840?
Limited driving only, diagnose soon
How much does it cost to fix P0840?
The estimated repair cost for P0840 is $17–56. Actual cost depends on your vehicle, location, and labor rates.
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