What it means
The transmission fluid pressure sensor/switch G circuit signal is above the expected level.
At a glance
- Usually lights the check-engine light
How it works
Transmission pressure sensor/switch G provides pressure-related input from a monitored transmission circuit, which this code does not identify. The transmission control module sets this code when the G circuit signal is higher than expected, such as from a signal wire shorted to reference voltage or another power source.
Common causes
Most likely first.
- Signal wire shorted to reference voltage
- Connector pins corroded - high contact resistance
- Supply wire pinched against B+ source
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
- Capture freeze-frame data and check sensor/switch G live data for a signal that remains high across changing operating conditions.
- Inspect the G sensor connector and harness for pin damage, corrosion, fluid intrusion, or wiring pinched against a power feed.
- Use the wiring diagram to test the signal circuit for a short to reference voltage or battery voltage, isolating it as the manufacturer directs.
- Check the sensor reference and ground circuits and connector terminal fit against the manufacturer's specification.
- If the circuit tests correctly, test pressure sensor/switch G and assess actual transmission pressure only using the manufacturer's procedure.
Common fixes
- Repair a signal wire shorted to a power or reference feed.
- Repair damaged or pinched wiring to sensor/switch G.
- Clean and secure the connector, replacing corroded or damaged terminals.
- Replace pressure sensor/switch G if it fails the specified electrical test.
Can I keep driving?
Avoid heavy loads and long trips if shifting is abnormal; stop if the transmission slips or gear engagement becomes unreliable. An inaccurate pressure signal can disrupt shift control, and a true pressure issue can cause further transmission wear.
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.