P2507: ECM/PCM Power Input Signal Low
The ECM/PCM switched-battery input reads below threshold while the ignition is on. Either the main relay does not close, the supply wire is broken or shorted to ground, or the battery is too low. Engine usually fails to start until the input recovers.
What P2507 means
P2507 is a generic OBD-II powertrain code in the computer & electrical 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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Common causes
- 01Main relay does not pull inMost likely
- 02Open supply wirePossible
- 03Severely discharged batteryPossible
Can I drive with P2507?
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 P2507
- 1
Confirm the code and save freeze-frame data
Read the codes with an OBD-II scan tool and note every code, not just P2507. 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 P2505. 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 main relay and power input 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: Main relay does not pull in; open supply wire; severely discharged battery. 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.
P2507 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
- Power input wire
- Battery
P2507 FAQ
What does P2507 mean?
P2507 means “ECM/PCM Power Input Signal Low”. The ECM/PCM switched-battery input reads below threshold while the ignition is on. Either the main relay does not close, the supply wire is broken or shorted to ground, or the battery is too low. Engine usually fails to start until the input recovers.
Is P2507 serious? Can I keep driving?
We rate P2507 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 P2507?
The most common causes, from most to least likely: Main relay does not pull in; Open supply wire; Severely discharged battery. Test before replacing parts, because several causes can set the same code.
How much does it cost to fix P2507?
Typical labor is about $50–$250 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 P2507 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 P2507 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.