P0899: Transmission Control System MIL Request Circuit High
MediumPowertrainTransmission
What does P0899 mean?
P0899 is a diagnostic trouble code indicating "Transmission Control System MIL Request Circuit High". The ECU is reading a voltage that is above the expected range. This can be caused by a short to power in the wiring, a failed sensor, or a connector issue in the transmission.
Common causes
- Damaged or corroded wiring harness
- Loose or disconnected electrical connector
- Failed transmission sensor or actuator
- Blown fuse in the related circuit
- Poor ground connection
What should you do?
Schedule a diagnostic appointment at your earliest convenience. The vehicle is generally safe to drive short distances, but the underlying issue should be addressed to prevent it from worsening.
Get a diagnosis for YOUR car
Code P0899 can mean different things depending on your vehicle. TorqueBot gives you a diagnosis specific to your make, model, and year.