ECM/PCM Power Input Signal Low
The P2507 code means the vehicle's onboard diagnostic system has detected: ECM/PCM Power Input Signal Low. This is a critical severity code.
- Keep driving?
- No -- stop driving
- DIY difficulty
- hard
- Estimated cost
- $100 - $1500 (parts and labor)
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Common Symptoms
- Engine will not start
- No scan tool communication with ECM
- All dashboard warning lights on
- Electrical accessories not functioning
Probable Causes (Ranked by Likelihood)
- Blown ECM main power fuse Very High
- Failed ECM power relay High
- Open circuit in ECM power supply wiring Moderate
- ECM internal power supply failure Low
Step-by-Step Diagnostic Procedure
-
Check ECM main power fuse and all related fuses
-
Test ECM power relay with multimeter
-
Measure voltage at ECM power input pins
-
Verify ignition switch signal reaching ECM
Frequently Asked Questions
Why won't my scan tool connect with P2507?
The ECM has low or no power input. Without power it cannot communicate with diagnostic tools.
Could a simple fuse cause a no-start?
Yes. A blown ECM power fuse completely disables the engine control module. Always check fuses first.
How do I know if my ECM has failed internally?
If all external components test good and the ECM still has no power, internal failure is likely requiring ECM replacement.
Sources
This page is built from documented references. Verify against your own service info before repair work.
P2507 on Diesel, EV & Equipment
The same code ID appears across other engines and platforms. The diagnostic flow varies by manufacturer — these are the platform-specific breakdowns:
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