P2506
ECM/PCM Power Input Signal Range/Performance
ECM/PCM power supply
Generic OBD-II
High
What it means
P2506 means the voltage feeding the engine control module is present but outside the range it expects — too low, too high, or unstable. Because the ECM depends on a clean, steady supply, this often traces back to the battery, grounds, wiring, or charging system, and it can cause stalling, hard starting, or erratic running until the power feed is corrected.
High
Can I keep driving? Risky — an out-of-range power feed to the engine computer can cause stalling, hard starting, or erratic running. Have it diagnosed before relying on the vehicle.
Common symptoms
What you'll notice
- Check-engine light on
- Intermittent stalling, hard starting, or a no-start
- Erratic running or flickering warning lights
- Possible battery or charging-system warning
Common causes
Most likely first
- Weak or discharged battery, or dirty/loose battery terminalsLikely
- Corroded or loose ECM power feed or ground connectionCommon
- Charging-system fault delivering low or high voltageCommon
- Damaged wiring or a failing relay in the ECM power circuitLess often
- Less commonly, a faulty ECM/PCMLess often
How to diagnose & fix
Work through it in order
- Test battery condition and charging-system voltage first.
- Clean and tighten the battery terminals and engine/body ground straps.
- Inspect the ECM power and ground circuits for corrosion and voltage drop under load.
- Check the related power-supply fuses and relays.
- Repair wiring as needed; only consider the ECM after a clean, stable supply is confirmed. Clear and retest.
FAQ
Quick answers
Is it safe to drive with P2506?+
Be cautious. Because this code involves the engine computer's power supply, it can lead to stalling or a no-start with little warning. Get the battery, charging system, and wiring checked promptly.
Can I just clear P2506?+
Clearing it won't fix a weak battery, bad ground, or charging fault — it returns and the drivability risk remains. Diagnose the power supply first.
Related codes
Often seen with P2506
Read & clear P2506 yourself
Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.
✓ Verified name — SAE J2012 / ISO 15031-6Guidance reviewed by OBD DashX