P2505 code meaning
ECM/PCM Power Input Signal
Powertrain system Generic code P25xx codes Check engine light
What P2505 means
P2505 covers the supply inputs of the engine module in general. GM documents it in the 2014 diesel engine table 14OBDG04: the module checks its permanent battery feed, the line that keeps the engine-off timer alive while the ignition is off. If that constant supply was interrupted, the module flags P2505 as soon as the ignition is on; a single event is enough, the test is evaluated a single time per trip and the code is GM type B, so the MIL follows on the second failing trip. Without that feed the module cannot know how long the engine was off, which other diagnostics rely on. Ford lists P2505 without MIL marker for the 2014 BOSS 302S. P2506 to P2509 narrow the fault to plausibility, low, high and intermittent.
P2505 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modeNot expected
- Repair difficultyMedium, DIY possible
- Typical labor0.3 to 2 hours
- Clears after repairAfter a drive cycle
Symptoms of P2505
- MIL after two trips (GM)
- Often no drivability complaint
- Learned values may be lost
Common causes of P2505
- Most likelyBattery disconnected or permanent-feed fuse removed or blown
- PossibleOpen or corroded permanent supply wire or connector
- Less likelySupply monitoring inside the module defective
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Main relayPower input wireECM
What each part of P2505 means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 2 | Generic code (second SAE range): it means the same on every make. |
| 5 | Area: vehicle speed, idle control and auxiliary inputs. |
| 05 | The exact fault in that area. |
What to do next
- Note P2505 and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about P2505
What does P2505 mean?
P2505 means "ECM/PCM Power Input Signal". P2505 covers the supply inputs of the engine module in general. It is a generic code, so it means the same on every make.
Is it safe to drive with P2505?
Usually yes, for a short time, if the check engine light is steady and the car drives normally. If the light flashes or the car runs badly, stop and have it checked.
Will P2505 fail an emissions test?
Yes, it can. P2505 is emissions-related, so most inspection programs fail a car while it is stored or while the check engine light is on.
How hard is P2505 to fix?
Difficulty: medium. A typical repair takes 0.3 to 2 hours of work. A careful DIY repair is possible with basic tools and a scanner.
Will P2505 clear itself after the repair?
After the repair the car has to complete a drive cycle (a mix of city and highway driving) before the test runs again. Until then the readiness monitor shows "not ready", which can fail an inspection.