P2508 code meaning
ECM/PCM Power Input Signal High
Powertrain system Generic code P25xx codes Check engine light
What P2508 means
P2508 is set when a supply input of the engine module reads above its permitted range. Ford documents it for the 2023 6.7 L Power Stroke diesel: the module checks its internal 5 V supply rail and flags P2508 once that rail exceeds 5.5 V, with continuous monitoring, roughly 5 s to mature, and the module awake (key on, running or after-run). The same group also blocks the reductant quality sensor test while P2507 or P2508 is present. On the 2014 BOSS 302S module Ford gives P2508 an M in the indicator column. A raised internal rail suggests a regulator fault inside the module or an external short to a higher voltage. P0563 reports excessive system voltage instead, P06A6 a sensor reference out of range. P2507 is the low partner.
P2508 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modePossible
- Repair difficultyHard
- Typical labor0.5 to 4 hours
- Clears after repairWhen cleared with a scanner
Symptoms of P2508
- Check engine lamp
- Other diagnostics such as the DEF quality test suspended
- Erratic sensor values possible
Common causes of P2508
- Most likelyInternal 5 V regulator of the engine module defective
- PossibleSupply or sensor wire shorted to battery voltage
- Less likelyOvervoltage from charging fault or jump start
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
ECMVoltage regulatorPower distribution
What each part of P2508 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. |
| 08 | The exact fault in that area. |
What to do next
- Note P2508 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 P2508
What does P2508 mean?
P2508 means "ECM/PCM Power Input Signal High". P2508 is set when a supply input of the engine module reads above its permitted range. It is a generic code, so it means the same on every make.
Is it safe to drive with P2508?
Drive gently and only to a workshop. With P2508 the car can go into limp mode (reduced power) to protect itself.
Will P2508 fail an emissions test?
Yes, it can. P2508 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 P2508 to fix?
Difficulty: hard. A typical repair takes 0.5 to 4 hours of work. This is a job for a workshop.
Will P2508 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.