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DTC code page

P2505: ECM/PCM Power Input Signal

Quick answer: The control module flagged a problem in the main power-input signal feeding the ECM/PCM.

Drivers also search this fault as ECM power input signal, PCM power input signal fault, engine computer power feed fault.

Severity: high Family: powertrain Related paths: 16
Meaning

What P2505 usually means

P2505 means the engine computer is no longer happy with the main power-input signal it depends on to stay awake and run the engine correctly. This is broader than a simple low-voltage accusation: the module sees its feed path behaving abnormally enough to question battery supply, fuse and relay integrity, wiring condition, or ground quality before it can trust the rest of the vehicle data.

Fast triage

Start here before chasing parts

  • Scan first: save freeze-frame and pending codes before clearing anything.
  • Confirm the complaint: compare the stored code with current drivability symptoms.
  • Use context: trims, live data, and related codes usually narrow the fault faster than guesswork.
  • Work simplest to hardest: leaks, connectors, maintenance items, and known patterns before expensive components.
Initial checks

What to check first

  • Verify battery condition and cranking voltage before blaming the module itself.
  • Check PCM power fuses, relay feeds, and grounds for looseness, heat damage, or corrosion.
  • Ask whether the complaint happens during crank, hot restart, bumps, or key transition because that timing usually narrows the branch fast.
Driving risk

Can you keep driving?

P2505 can turn into a no-start, stall, or repeated module reset if the PCM loses a clean power feed. Do not trust the vehicle for normal use until the supply path is proven stable.

High urgency: If symptoms are active, reduce driving and diagnose quickly before secondary damage builds.
Likely causes

Common causes behind this code

  • Weak or unstable battery supply feeding the PCM
  • Blown, heat-damaged, or high-resistance fuse in the PCM power path
  • Corroded battery, ground, or module power connections
  • PCM power relay or fuse-box terminal problem
  • Harness damage causing voltage drop or momentary power interruption

Cause phrases often tied to this code: PCM power feed, battery supply, fuse box, ground fault, relay feed.

Diagnostic order

Suggested workflow

  1. Capture freeze-frame and note whether the fault sets during crank, stall, hot soak, or restart.
  2. Load-test the battery and confirm charging voltage is sane before chasing the PCM branch alone.
  3. Voltage-drop test the PCM power feed and ground paths under actual load.
  4. Inspect the PCM relay, fuse-box terminals, and harness sections for heat, spread pins, or intermittent contact.
  5. Confirm stable PCM supply after the repair through repeated key cycles and a road test.
Avoid guesswork

Common mistakes

  • Jumping straight to PCM replacement without proving the supply path first.
  • Checking battery voltage at rest only and never under crank or hot-load conditions.
  • Ignoring grounds and fuse-box resistance because the fuse itself looks visually fine.
Repair path

Practical fix guidance

  • Repair the proven supply-path fault first: battery, cables, relay, fuse-box terminal, wiring, or ground.
  • Retest under the same crank or hot-soak conditions that triggered the code originally.
  • If other voltage or relay codes remain, treat them as a system story instead of isolated coincidences.
Vehicle context

Affected brands in this MVP

Brand hubs help broaden internal linking now and can evolve into make-specific diagnostic notes later.

Aliases and common searches

English phrases tied to P2505

Useful when the driver knows the wording but not the exact DTC yet.

  • ECM power input signal
  • PCM power input signal fault
  • engine computer power feed fault
Related search intent

Queries this page can answer naturally

  • P2505 code meaning
  • what does P2505 mean
  • ECM PCM power input signal
FAQ

Quick questions about P2505

Is P2505 the same as a bad PCM?

No. Most P2505 cases are supply-path problems like voltage drop, relay issues, fuse-box trouble, or poor grounds rather than a failed computer.

Can low battery voltage trigger P2505?

Yes. If battery or cable condition lets PCM feed voltage sag during crank or restart, P2505 becomes much more believable.

What should I test first with P2505?

Start with battery condition, PCM feed fuses, relay power, and voltage drop on the power and ground side before condemning the module.