P0990
Transmission Fluid Pressure Sensor/Switch E Circuit High
Transmission
Generic OBD-II
Medium
What it means
P0990 means the transmission control module sees a high-voltage signal from fluid pressure sensor/switch 'E', which monitors internal transmission pressure. With a bad reading the transmission may shift harshly, change gears unpredictably, or fall back to limp mode. The cause is typically the sensor itself or a wiring/connection fault, not internal transmission damage.
Medium
Can I keep driving? Often driveable, but the transmission may shift oddly or enter limp mode because it can't read pressure correctly — repair it before it strains the gearbox.
Common symptoms
What you'll notice
- Check-engine light on
- Harsh, delayed, or abnormal shifting
- Erratic or unpredictable gear changes
- May default to limp/failsafe mode
Common causes
Most likely first
- Faulty transmission fluid pressure sensor/switch 'E'Likely
- Short-to-power or open in the sensor circuit wiringCommon
- Loose or corroded electrical connectionsCommon
- Failed transmission control module (TCM)Less often
How to diagnose & fix
Work through it in order
- Read freeze-frame data and compare the sensor reading to actual/expected pressure.
- Inspect the sensor wiring and connector for a short to power, opens, or corrosion.
- Test the sensor's reference voltage and signal; replace the sensor if faulty.
- Repair the high-voltage circuit fault, then clear and road-test.
- If wiring and sensor are good, suspect the TCM.
FAQ
Quick answers
Is it safe to drive with P0990?+
Usually yes for short distances, but shifting may be off or defaulted, so have it diagnosed soon.
Can I just clear P0990?+
It returns until the sensor or its circuit is repaired, and the transmission may keep using default pressure logic.
Related codes
Often seen with P0990
Read & clear P0990 yourself
Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.
✓ Verified name — SAE J2012 / ISO 15031-6Guidance reviewed by OBD DashX