Code result
P25B7
Auxiliary Ignition Switch On/Start Position Circuit
Moderate severity
What it means
General electrical fault on the auxiliary ignition switch On/Start input. Used on commercial vehicles or upfit applications where a second ignition switch (in a sleeper cab, work platform or crew compartment) can crank the engine.
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
Open or shorted wire
highOne of the most commonly reported causes for this code — check this first.
Related help
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