P0990 Fault Code

Transmission Fluid Pressure Sensor/Switch E Circuit High

• What does that mean?
• Symptoms
• Causes
• Solutions

The P0990 fault code indicates an issue with the Transmission Fluid Pressure Sensor/Switch E Circuit, specifically that it is reading a high voltage or pressure. This fault often signals that the transmission is unable to regulate fluid pressure correctly, which can affect shifting performance and overall drivability.

What are the symptoms of the P0990 code?

When the P0990 code is present, you may experience symptoms such as:

• Delayed or harsh shifting between gears.
• Transmission overheating due to insufficient pressure regulation.
• Transmission not shifting at all, resulting in limited mobility.
• Potential illumination of the check engine light (CEL) on the dashboard.

What causes the P0990 code?

Several factors can lead to this code being triggered, such as:

• A faulty transmission fluid pressure sensor/switch.
• Wiring issues, such as short circuits or damaged insulation in the sensor circuit.
• Low transmission fluid levels or dirty transmission fluid, affecting sensor operation.
• Problems within the transmission control module (TCM), which may misinterpret sensor readings.

How to fix P0990?

To resolve the P0990 fault code, follow these steps:

• Inspect and clean the transmission fluid and ensure it is at the correct level.
• Check the fluid pressure sensor and wiring for any signs of damage or wear, replacing any faulty components as needed.
• Test the sensor's electrical connections with a multimeter, replacing the sensor if it is not within the manufacturer's specifications.
• If the issue persists, consider having the transmission control module diagnosed for faults.