If the ECU cannot receive data from the transmission fluid pressure sensor F (‘F’ generally means #5), the ECU will not be able to determine the most appropriate shift strategy. So if there is an intermittent problem with the transmission fluid pressure switch, a P0996 DTC will be saved.
How Serious is the Code?
A P0996 diagnostic trouble code is very serious, and usually results in a number of transmission problems like the inability of the transmission to shift into gear and limp mode.
Symptoms of a P0996 include:
- Transmission seems to slam into gear
- Transmission unable to shift into gear
- Limp Mode
- Low transmission fluid
- Dirty transmission fluid
- Broken/corroded connectors
- Damaged wiring
- The transmission line pressure sensor/transmission fluid pressure sensor has gone bad
- Valve body issues
How to Diagnose the Code?
The process of figuring out what’s causing a P0996 OBDII trouble code, should start with a check of the transmission fluid level and condition. Low or dirty transmission fluid can severely affect the amount of hydraulic pressure inside the gearbox, so the transmission should be serviced immediately. If there is not a problem there, then the wiring and connectors between the transmission line pressure sensor and the ECU should be checked for signs of damage and corrosion. If no issues are found here, then the transmission fluid pressure sensor itself will need to be tested. If it works fine, then suspect an internal mechanical problem.
What Repairs Will Fix P0996?
- Add or change transmission fluid and filter
- Repair or replace damaged wiring and connectors
- Replace transmission fluid pressure sensor/switch
- Repair or install remanufactured valve body
- P0992 – Transmission Fluid Pressure Sensor/Switch “F” Circuit
- P0993 – Transmission Fluid Pressure Sensor/Switch “F” Circuit Range/Performance
- P0994 – Transmission Fluid Pressure Sensor/Switch “F” Circuit Low
- P0995 – Transmission Fluid Pressure Sensor/Switch “F” Circuit High