P277D: Electric/Auxiliary Transmission Fluid Pump B Motor Over Temperature
The second auxiliary transmission fluid pump motor has reached over-temperature. Sustained high duty or insufficient cooling.
What P277D means
P277D is a generic OBD-II powertrain code in the transmission group.
- 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
- 01Sustained high duty cycleMost likely
- 02Cooling air or fluid path blockedPossible
Can I drive with P277D?
No. Stop and let the engine cool.
If the temperature gauge is high or you see steam, pull over and switch off. Driving an overheating engine can warp the head and blow the head gasket.
Why we rate it urgent
- Engine over-temperature can cause head-gasket and engine damage
- 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 P277D
- 1
Confirm the code and save freeze-frame data
Read the codes with an OBD-II scan tool and note every code, not just P277D. Save the freeze-frame data (speed, load, temperature when the fault set) before clearing anything; it tells you when the fault happens.
- 2
Check for related codes first
Look for P0DE4. Related codes often share a cause; a circuit or sensor code usually needs fixing before a performance code like this one.
- 3
Check live data
Watch the related sensor and actuator readings in live data (Aux trans pump B, Pump motor) 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: Sustained high duty cycle; cooling air or fluid path blocked. 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.
P277D 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
- Aux trans pump B
- Pump motor
P277D FAQ
What does P277D mean?
P277D means “Electric/Auxiliary Transmission Fluid Pump B Motor Over Temperature”. The second auxiliary transmission fluid pump motor has reached over-temperature. Sustained high duty or insufficient cooling.
Is P277D serious? Can I keep driving?
We rate P277D as urgent severity. No. Stop and let the engine cool. If the temperature gauge is high or you see steam, pull over and switch off. Driving an overheating engine can warp the head and blow the head gasket.
What causes P277D?
The most common causes, from most to least likely: Sustained high duty cycle; Cooling air or fluid path blocked. Test before replacing parts, because several causes can set the same code.
How much does it cost to fix P277D?
Typical labor is about $125–$440 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 P277D 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 P277D 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.