Code result
P0178
Fuel Composition Sensor Circuit Low Input
Moderate severity
What it means
The flex-fuel composition sensor signal is below the minimum threshold. Likely shorted to ground, open circuit or failed sensor.
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
Signal wire shorted to ground
highOne of the most commonly reported causes for this code — check this first.
Sensor failed
mediumA plausible cause — test and verify before replacing parts.
Connector pins corroded - high contact resistance
lowLess common, but worth ruling out after the more likely causes.
Related help
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