Symptom
Transmission will not change gear
The transmission holds one ratio and will not move out of it, in either direction.
Most often this is limp mode, which is the transmission protecting itself rather than failing. When the module stops trusting a sensor or a solenoid, it stops making shift decisions and locks into a single gear chosen so the car can still be driven — commonly third or fourth, occasionally second. The car will pull away sluggishly and rev hard at speed, but it moves.
The distinguishing sign is that it is consistent. A gearbox stuck in one gear every time, from cold, is behaving deliberately. A gearbox that changes gear sometimes and not others is a different and usually worse problem — slipping elements or falling pressure.
Try a restart, once. Some faults are latched for an ignition cycle and clear on the next start, which tells you the fault is intermittent rather than fixing it.
Do not drive far like this. The car is usable enough to reach help and not much more: revving hard in a low gear overheats the fluid, and a transmission already unsure of itself does not need the heat.
Also described as: stuck in gear, limp mode transmission, will not shift, transmission stuck, no gear change, locked in one gear, wont change gear, گیربکس دنده عوض نمیکند, دنده بالا نمیرود, no cambia marcha, caja no cambia, no sube de marcha, الجير لا يبدل, ناقل الحركة لا ينقل, ما يطلع غيار
Some causes mean you should stop driving
6 of the 153 codes that produce this symptom indicate a fault where continuing to drive risks damage or is unsafe. If the symptom is sudden or severe, treat it as one of those until a scan says otherwise.
What this usually means
Most often this is limp mode, which is the transmission protecting itself rather than failing. When the module stops trusting a sensor or a solenoid it stops making shift decisions and locks into a single gear chosen so the car can still be driven. The car will pull away sluggishly and rev hard at speed, but it moves — and that is the design working.
The distinguishing sign is that it is consistent. A gearbox stuck in one ratio every time, from cold, is behaving deliberately. A gearbox that changes gear sometimes and not others is a different and usually worse problem — slipping elements or falling pressure — and the two want opposite diagnostic approaches.
Try a restart, once. Some faults are latched for an ignition cycle and clear on the next start. That tells you the fault is intermittent rather than fixing it, which is worth knowing before a workshop tests a car that is behaving perfectly on arrival.
When it is genuinely mechanical rather than protective, the population is narrow: a valve body whose spools are stuck, a shift solenoid that has failed in one position, or line pressure too low to apply any element it is not already holding. Fluid level and condition come before all of them, because both faults look identical from the driver's seat.
Do not drive far like this. The car is usable enough to reach help and not much more: revving hard in a low gear puts heat into fluid that is already being asked to work in a transmission unsure of itself.
Working through it
| What you find | Likely cause | How to confirm it | What fixes it |
|---|---|---|---|
| Same ratio every time, consistent from cold | Limp mode — a deliberate decision the module has latched | Read transmission codes. Consistency from cold is the sign of a strategy rather than a failure. | Diagnose the named fault. Do not treat the fixed gear as the problem; it is the protection. |
| Normal shifting returns after a restart, then goes again | An intermittent input latched for the driving cycle | Restart once and note the result, then log live data on a road test reproducing it. | Repair what the log names. Do not clear codes before recording the freeze frame. |
| Changes gear sometimes and not others | Slipping elements or falling pressure, not a control decision | Measure line pressure hot and cold and check fluid condition. Inconsistency is the discriminator. | Diagnose as slipping. Stop driving it — this is the case where mileage changes the repair. |
| Codes name shift solenoids or the valve body | A solenoid failed in position, or valve spools stuck with varnish and debris | Command each solenoid on a scan tool and watch for a response. Inspect the pan and magnet for debris when opened. | Renew the solenoid or service the valve body, then relearn adaptation. |
| Fluid low, dark, or smelling burnt | Pressure cannot be made or held — the same symptom by a completely different route | Check level by the manufacturer's procedure at the specified temperature. | Correct level and condition first. This is the cheapest cause on the page and the one most often skipped. |
| Selector display wrong as well | The range switch or selector position sensor — the module does not know which gear is requested | Compare the live gear position against the lever. The starter interlock and reverse lights share this switch and confirm it for free. | Adjust or renew the range switch. Cheaper than anything inside the transmission. |
-
Same ratio every time, consistent from cold
- Likely cause
- Limp mode — a deliberate decision the module has latched
- How to confirm it
- Read transmission codes. Consistency from cold is the sign of a strategy rather than a failure.
- What fixes it
- Diagnose the named fault. Do not treat the fixed gear as the problem; it is the protection.
-
Normal shifting returns after a restart, then goes again
- Likely cause
- An intermittent input latched for the driving cycle
- How to confirm it
- Restart once and note the result, then log live data on a road test reproducing it.
- What fixes it
- Repair what the log names. Do not clear codes before recording the freeze frame.
-
Changes gear sometimes and not others
- Likely cause
- Slipping elements or falling pressure, not a control decision
- How to confirm it
- Measure line pressure hot and cold and check fluid condition. Inconsistency is the discriminator.
- What fixes it
- Diagnose as slipping. Stop driving it — this is the case where mileage changes the repair.
-
Codes name shift solenoids or the valve body
- Likely cause
- A solenoid failed in position, or valve spools stuck with varnish and debris
- How to confirm it
- Command each solenoid on a scan tool and watch for a response. Inspect the pan and magnet for debris when opened.
- What fixes it
- Renew the solenoid or service the valve body, then relearn adaptation.
-
Fluid low, dark, or smelling burnt
- Likely cause
- Pressure cannot be made or held — the same symptom by a completely different route
- How to confirm it
- Check level by the manufacturer's procedure at the specified temperature.
- What fixes it
- Correct level and condition first. This is the cheapest cause on the page and the one most often skipped.
-
Selector display wrong as well
- Likely cause
- The range switch or selector position sensor — the module does not know which gear is requested
- How to confirm it
- Compare the live gear position against the lever. The starter interlock and reverse lights share this switch and confirm it for free.
- What fixes it
- Adjust or renew the range switch. Cheaper than anything inside the transmission.
Codes that produce this symptom (153)
Listed with the codes that most typically present this way first — the likeliest place to start.
- P072F Stuck in Gear 4 Typical of this code Moderate
- P08A6 Gear Lever Position Sensor System - Multiple Sensor Correlation Typical of this code High
- P2706 Shift Solenoid F Typical of this code Moderate
- P2707 Shift Solenoid F Performance/Stuck Off Typical of this code High
- P2708 Shift Solenoid F Stuck On Typical of this code Stop driving High
- P2709 Shift Solenoid F Electrical Typical of this code Moderate
- P2710 Shift Solenoid F Intermittent Typical of this code Moderate
- P2711 Unexpected Mechanical Gear Disengagement Typical of this code Stop driving High
- P2712 Hydraulic Power Unit Leakage Typical of this code Stop driving High
- P272A Transmission Range Select Motor Control Circuit Typical of this code High
- P272B Transmission Range Select Motor Control Circuit Current Too High Typical of this code High
- P272C Park Pawl Motor Control Circuit Typical of this code High
- P272D Park Pawl Motor Control Circuit Current Too High Typical of this code High
- P27E7 Transmission Range Control B Circuit/Open Typical of this code High
- P27E8 Transmission Range Control B Circuit Performance Typical of this code High
- P27E9 Transmission Range Control B Circuit Low Typical of this code Moderate
- P27EA Transmission Range Control B Circuit High Typical of this code Moderate
- P27EB Transmission Range Control A Position Sensor/Switch Circuit/Open Typical of this code Moderate
- P27EC Transmission Range Control A Position Sensor/Switch Circuit Range/Performance Typical of this code Moderate
- P27ED Transmission Range Control A Position Sensor/Switch Circuit Low Typical of this code Moderate
- P27EE Transmission Range Control A Position Sensor/Switch Circuit High Typical of this code Moderate
- P27EF Transmission Range Control B Position Sensor/Switch Circuit/Open Typical of this code Moderate
- P27F0 Transmission Range Control B Position Sensor/Switch Circuit Range/Performance Typical of this code Moderate
- P27F1 Transmission Range Control B Position Sensor/Switch Circuit Low Typical of this code Moderate
- P27F2 Transmission Range Control B Position Sensor/Switch Circuit High Typical of this code Moderate
Information, not instruction
CarGeek is a reference, not a service manual. Its pages are written from public sources and from what other people have found, never from a manufacturer's own service information, so they can be wrong or incomplete for your particular vehicle. Some of what they describe carries real risk: high voltage, fuel under pressure, stored energy, hot and moving parts.
Have anything you intend to act on checked by a trained person against the manufacturer's own procedure for your vehicle. Nothing here replaces that procedure.
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