P0990 code indicates a high voltage condition in the transmission fluid pressure sensor or switch “E” circuit.
P0990 Transmission Fluid Pressure Sensor/Switch “E” Circuit High
Code symptoms P0990.
1. Harsh shifting: The transmission may experience harsh or abrupt shifting when the P0990 code is present.
2. Transmission faults: Vehicles with this code may experience transmission faults, such as slipping or difficulty shifting gears.
3. Illuminated or blinking check engine light: The check engine light may illuminate or blink when the P0990 code is detected by the vehicle’s onboard diagnostic system.
4. Reduced fuel efficiency: The vehicle’s fuel efficiency may decrease due to the impact of the P0990 code on the transmission system.
Causes of the code P0990.
1. Faulty transmission fluid pressure sensor or switch
2. Wiring harness issues such as a short circuit or open circuit in the transmission fluid pressure sensor or switch circuit
3. Corrosion or poor connections at the transmission fluid pressure sensor or switch
4. Issues with the transmission control module (TCM) that is causing inaccuracies in the sensor or switch readings
5. Excessive transmission fluid pressure due to a blockage or malfunction within the transmission system
Code Solutions P0990.
1. Check the transmission fluid level and condition. Low fluid level or dirty or burnt fluid can cause improper pressure readings. Top up the fluid if necessary or replace it if it is in poor condition.
2. Inspect the wiring harness and connectors leading to the transmission fluid pressure sensor or switch “E”. Look for any damage, wear, or corrosion that could be causing a high circuit resistance. Repair or replace any faulty components.
3. Test the transmission fluid pressure sensor or switch “E” using a multimeter to ensure it is functioning properly. If it is faulty, replace it with a new sensor to correct the high circuit reading.
4. Reset the powertrain control module (PCM) by disconnecting the battery for a few minutes. This can sometimes clear false codes and reset the sensor readings. Reconnect the battery and check if the code reappears.
5. If the issue persists, seek assistance from a professional mechanic or dealership to conduct a more in-depth diagnosis using specialized equipment to pinpoint the exact cause of the high circuit reading. They may need to perform further tests or inspections to determine the root of the problem.