A transmission fluid pressure sensor monitors the level of hydraulic pressure inside the transmission, so the ECU will know how much it has (hydraulic pressure) to execute shifts. If there is an intermittent problem with the signal coming back from this sensor, a P0849 DTC will be saved in the ECU memory.
How Serious is the Code?
In terms of severity, a P0849 diagnostic trouble code ranks pretty high. It means either there is a problem with the amount of hydraulic pressure, or the sensor has gone bad. In either case, drivability issues can occur.
Symptoms of a P0849 include:
- Delayed, harsh or erratic shifts
- Transmission not able to shift gears
- Torque converter clutch failure
- Transmission overheating
- Reduced fuel economy
- Not enough transmission fluid
- Dirty transmission fluid / filter
- Transmission fluid leak
- Damaged wiring/connector
- Malfunctioning pressure control solenoid
- Malfunctioning pressure regulator
- Bad transmission fluid pressure sensor
- Defective transmission pump
- Blocked pressure passage
- Valve body issue
- TCM or ECU failure
How to Diagnose the Code?
In order to diagnose a P0849 OBDII trouble code, a mechanic should start by looking at the level and condition of the transmission fluid. If it is clean and bright, the wiring, connectors and sensor itself should be tested. If no issues are found, further mechanical diagnosis will be needed.
What Repairs Will Fix P0849?
- Change transmission fluid and filter
- Repair leaks
- Repair or replace damaged wiring and connectors
- Replace transmission fluid pressure sensor
- Repair or replace torque converter
- Repair or replace valve body
- Replace transmission pump
- Replace pressure control solenoid
- Replace pressure regulator
- Reprogram or replace TCM