P2511: ECM/PCM Power Relay Sense Circuit Intermittent
The sense (feedback) line that lets the ECM verify the main power relay has actually closed shows intermittent dropouts. The ECM expects to see battery voltage on this line whenever the relay is energised — short losses suggest aged contacts, vibration or chafed wiring.
What P2511 means
P2511 is a generic OBD-II powertrain code in the computer & electrical group. In plain English: the computer found an electrical fault in that circuit: an open, short or bad connection, or a failed component.
- Check engine light
- Usually on
- Emissions-related
- No
- Limp mode possible
- Not typical
- Drive cycle to clear
- Not required
Get it fixed
Post this code once and get quotes from local mechanics. Free to post.
Makes the repair and parts links below specific to your car. Kept in this browser only.
Common causes
- 01Aged main relay contactsMost likely
- 02Chafed sense wire shorting intermittentlyPossible
- 03Connector with intermittent contact under vibrationLess likely
Can I drive with P2511?
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 P2511
- 1
Confirm the code and save freeze-frame data
Read the codes with an OBD-II scan tool and note every code, not just P2511. 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
Test the circuit
Inspect the wiring and connector at the main relay and sense wire 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: Aged main relay contacts; chafed sense wire shorting intermittently; connector with intermittent contact under vibration. 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.
P2511 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
- Main relay
- Sense wire
P2511 FAQ
What does P2511 mean?
P2511 means “ECM/PCM Power Relay Sense Circuit Intermittent”. The sense (feedback) line that lets the ECM verify the main power relay has actually closed shows intermittent dropouts. The ECM expects to see battery voltage on this line whenever the relay is energised — short losses suggest aged contacts, vibration or chafed wiring.
Is P2511 serious? Can I keep driving?
We rate P2511 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 P2511?
The most common causes, from most to least likely: Aged main relay contacts; Chafed sense wire shorting intermittently; Connector with intermittent contact under vibration. Test before replacing parts, because several causes can set the same code.
How much does it cost to fix P2511?
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 P2511 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 P2511 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.