Code result
C05B4
Brake Booster Temperature Sensor C Circuit High
Moderate severity
What it means
Brake booster temperature sensor C signal voltage above expected range. Boost control tracks commanded vs. actual manifold pressure; persistent deviation means wastegate, vanes, hose or actuator are not delivering the requested pressure.
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 battery
highOne of the most commonly reported causes for this code — check this first.
Connector pins corroded - high contact resistance
lowLess common, but worth ruling out after the more likely causes.
Supply wire pinched against B+ source
lowLess common, but worth ruling out after the more likely causes.
Related help
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