Gate Select Direction Circuit Low
What it means
P2791 means the transmission controller sees low voltage on the gate-select direction circuit — part of the actuator system that moves the shift mechanism between gear gates on automated-manual and dual-clutch transmissions. Because it controls gear selection, a fault here can cause hard or failed engagement and limp mode, so it shouldn't be ignored.
Can I keep driving? Sometimes — the transmission may fail to select gears or drop into limp mode; drive gently and get it checked before it strands you.
Real-world scan data
Figures reflect only diagnostic scans recorded through our own apps and tools. Cars are typically scanned because a symptom or warning light prompted it, so these counts describe our scan records — not the incidence of faults in any model, and not the quality, reliability, or safety of any vehicle. No comparison between manufacturers or models is implied. All trademarks belong to their respective owners; no affiliation or endorsement is implied.
Common symptoms
What you'll notice
- Check-engine light on, often with a transmission warning
- Hard, delayed, or failed gear engagement
- Transmission stuck in one gear or in limp/failsafe mode
- Grinding or no drive when selecting a gear (automated-manual/DCT)
Common causes
Most likely first
- Faulty gate-select actuator or its position sensorLikely
- Open or short-to-ground in the gate-select signal circuitCommon
- Corroded or loose connector at the shift-actuator assemblyCommon
- Low or contaminated transmission fluid affecting actuator hydraulicsLess often
- Transmission control module fault (least likely)Less often
How to diagnose & fix
Work through it in order
- Read freeze-frame data and scan for other shift-actuator or fork codes.
- Check transmission fluid level and condition first.
- Inspect the gate-select actuator connector and wiring for a short to ground or open circuit.
- Measure the actuator/sensor signal voltage against spec through its travel.
- If the circuit is good, test the gate-select actuator; replace if faulty. Clear and re-test.
FAQ
Quick answers
Is it safe to drive with P2791?+
Can I just clear P2791?+
Related codes
Read & clear P2791 yourself
Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.