What it means
The transmission fluid pressure sensor/switch G circuit has an electrical fault. The code does not identify the hydraulic circuit monitored by sensor G.
At a glance
- Usually lights the check-engine light
How it works
Transmission pressure sensor/switch G provides an electrical signal related to fluid pressure in a monitored transmission circuit; the code does not identify which hydraulic circuit G represents. The transmission control module sets this code when the G circuit has an electrical fault, such as an open, short, or poor connection.
Common causes
Most likely first.
- Faulty pressure sensor/switch
- Open or shorted wiring
- Poor electrical connection
Symptoms
- Check engine or transmission warning light on
- Harsh, delayed, or missing shifts
- Possible limp mode (locked in one gear)
- Slipping or shuddering during gear changes
How to diagnose it
- Save freeze-frame data and read transmission live data and related codes to see when the G circuit fault occurred.
- Inspect the G sensor/switch connector and accessible harness for loose fit, fluid intrusion, corrosion, or damaged wiring.
- Check the transmission fluid condition and level using the vehicle manufacturer's procedure, since fluid problems may accompany shift symptoms but do not by themselves prove an electrical fault.
- Use the wiring diagram to test the G circuit for opens, shorts, and poor terminal contact, following the manufacturer's isolation procedure.
- If wiring and connections are sound, test sensor/switch G and its module input using the manufacturer's procedure.
Common fixes
- Reconnect or repair a loose, damaged, or corroded G circuit connector.
- Repair an open or short in the wiring to pressure sensor/switch G.
- Replace sensor/switch G if it fails the specified electrical test.
- Repair a confirmed control-module input fault after checking the circuit.
Can I keep driving?
Limit driving if shifts are harsh, delayed, slipping, or the transmission enters a limited operating mode; stop if gear engagement becomes unreliable. Continued driving with abnormal shifting can increase transmission damage.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.