P27F4: Gear Shift Lock Solenoid/Actuator A Performance/Stuck On
The shift lock solenoid for selector lever A stays engaged when release is commanded. Driver cannot move the selector out of Park or away from the locked gate.
What P27F4 means
P27F4 is a generic OBD-II powertrain code in the transmission group. In plain English: the signal is within electrical limits but doesn’t make sense compared with other readings, so the part or system isn’t performing as expected.
- Check engine light
- Usually on
- Emissions-related
- No
- Limp mode possible
- Not typical
- Drive cycle to clear
- Not required
Get it fixed
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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
Common causes
- 01Lock actuator mechanically stuckMost likely
- 02Control driver stuck onPossible
- 03Carbon or debris buildup preventing free movementLess likely
Can I drive with P27F4?
Usually yes, for a short time.
The car will often drive normally, but get it diagnosed soon. If you notice rough running, warning lights flashing, overheating or a burning smell, stop driving.
Why we rate it moderate
- Turns on the check engine light
Severity is our rule-based rating from the code’s flags in OBDex and the system it affects, not an inspection of your car. If the check engine light is flashing, or you notice overheating, low oil pressure, or brake or steering problems, stop driving and get help.
How to diagnose P27F4
- 1
Confirm the code and save freeze-frame data
Read the codes with an OBD-II scan tool and note every code, not just P27F4. Save the freeze-frame data (speed, load, temperature when the fault set) before clearing anything; it tells you when the fault happens.
- 2
Fix other faults first
If other codes are stored, start with power-supply, sensor-circuit and communication codes. They can cause this code as a side effect.
- 3
Check live data
Watch the related sensor and actuator readings in live data (Shift lock solenoid A, Shift lock actuator A, TCM) and compare them with expected values in the service information for your vehicle.
- 4
Test the likely causes in order
Start with the most likely cause and work down: Lock actuator mechanically stuck; control driver stuck on; carbon or debris buildup preventing free movement. Test before replacing parts.
- 5
Check for recalls and service bulletins
Look up recalls for your exact vehicle with its VIN, and ask a dealer about technical service bulletins (TSBs). Manufacturers sometimes issue software updates or extended warranties for known faults.
- 6
Clear the code and verify the repair
After the repair, clear the code and drive the car under the conditions in the freeze-frame data to confirm it does not return.
P27F4 repair cost estimate
Estimate, not a quote. Labor times are typical ranges for this code from OBDex, and $125/hr is an assumed rate. Shop rates and labor times vary by vehicle and region. Diagnosis time may be billed separately.
- DIY difficulty
- Moderate
- Good DIY job?
- Usually a shop job
Needs a scan tool and some experience with testing.
Parts and systems involved
- Shift lock solenoid A
- Shift lock actuator A
- TCM
P27F4 FAQ
What does P27F4 mean?
P27F4 means “Gear Shift Lock Solenoid/Actuator A Performance/Stuck On”. The shift lock solenoid for selector lever A stays engaged when release is commanded. Driver cannot move the selector out of Park or away from the locked gate.
Is P27F4 serious? Can I keep driving?
We rate P27F4 as moderate severity. Usually yes, for a short time. The car will often drive normally, but get it diagnosed soon. If you notice rough running, warning lights flashing, overheating or a burning smell, stop driving.
What causes P27F4?
The most common causes, from most to least likely: Lock actuator mechanically stuck; Control driver stuck on; Carbon or debris buildup preventing free movement. Test before replacing parts, because several causes can set the same code.
How much does it cost to fix P27F4?
Typical labor is about $65–$375 at an assumed $125/hour shop rate, plus parts. That is an estimate, not a quote: labor times and rates vary by vehicle and region, and diagnosis may be billed separately.
Can I fix P27F4 myself?
DIY difficulty is moderate. Most owners leave this to a shop because it needs involved testing or specialist tools. Always confirm the cause before buying parts.
Will P27F4 clear itself?
If the fault was intermittent, the warning may go off once the computer stops seeing it, but the code stays in memory. Fix the cause; clearing the code alone doesn’t repair anything.