Possible causes
– Transmission Fluid Pressure Sensor A harness is open or shorted
– Transmission Fluid Pressure Sensor A poor electrical connection
– Faulty Transmission Fluid Pressure Sensor A
– Transmission Valve Body
– Transmission Fluid Pressure Sensor A poor electrical connection
– Faulty Transmission Fluid Pressure Sensor A
– Transmission Valve Body
Symptoms
– Engine Light ON (or Service Engine Soon Warning Light)
P0840 INFINITI OBD Code Description
The transmission fluid pressure sensor A (primary pressure sensor) detects primary pressure of Continuously Variable Transmission (CVT) and sends Transmission Control Module (TCM) the signal.