Code result
P2509
ECM/PCM Power Input Signal Intermittent
Moderate severity
What it means
The ECU detects sporadic interruptions of its supply voltage. The fault is set when supply drops below a threshold for short periods, often during cranking or due to a poor connection.
Is it safe to drive?
Use caution
The vehicle is usually drivable for short distances, but the problem can worsen or affect emissions. Diagnose and repair as soon as practical.
Most likely causes
Poor battery cable connection
highOne of the most commonly reported causes for this code — check this first.
Intermittent main relay
mediumA plausible cause — test and verify before replacing parts.
Connector with intermittent contact under vibration
lowLess common, but worth ruling out after the more likely causes.
Related help
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