P2517: A/C Refrigerant Pressure Sensor B Circuit Low
A/C refrigerant pressure sensor B signal voltage reads below the lower limit. Either a short to ground in the signal wire, an open reference voltage at the sensor, or an internal short. The ECM ignores the reading and disables A/C closed-loop control until the circuit recovers.
What P2517 means
P2517 is a generic OBD-II powertrain code in the speed, idle & cruise group. In plain English: the computer sees a voltage on that circuit that is lower than it should ever be — often a short to ground, an open, or a failed sensor.
- 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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Common causes
- 01Signal wire shorted to groundMost likely
- 02Missing 5 V reference at the sensorPossible
- 03Connector pins corroded - high contact resistanceLess likely
Can I drive with P2517?
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 P2517
- 1
Confirm the code and save freeze-frame data
Read the codes with an OBD-II scan tool and note every code, not just P2517. 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 P2515. Related codes often share a cause; a circuit or sensor code usually needs fixing before a performance code like this one.
- 3
Test the circuit
Inspect the wiring and connector at the a/c pressure sensor b and sensor wiring for damage, corrosion or chafing. With a multimeter, check supply voltage, ground and signal against the specifications in the service manual for your vehicle.
- 4
Test the likely causes in order
Start with the most likely cause and work down: Signal wire shorted to ground; missing 5 V reference at the sensor; connector pins corroded - high contact resistance. 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.
P2517 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?
- Yes, with a scan tool
Needs a scan tool and some experience with testing.
Parts and systems involved
- A/C pressure sensor B
- Sensor wiring
P2517 FAQ
What does P2517 mean?
P2517 means “A/C Refrigerant Pressure Sensor B Circuit Low”. A/C refrigerant pressure sensor B signal voltage reads below the lower limit. Either a short to ground in the signal wire, an open reference voltage at the sensor, or an internal short. The ECM ignores the reading and disables A/C closed-loop control until the circuit recovers.
Is P2517 serious? Can I keep driving?
We rate P2517 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 P2517?
The most common causes, from most to least likely: Signal wire shorted to ground; Missing 5 V reference at the sensor; Connector pins corroded - high contact resistance. Test before replacing parts, because several causes can set the same code.
How much does it cost to fix P2517?
Typical labor is about $50–$190 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 P2517 myself?
DIY difficulty is moderate. Many owners can handle it with a scan tool, a multimeter and basic hand tools. Always confirm the cause before buying parts.
Will P2517 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.