Code result
P340C
Deactivation/Exhaust Valve Control Circuit Bank 1
Moderate severity
What it means
Generic electrical fault on the cylinder deactivation/exhaust valve control circuit on bank 1. The exhaust control valve modulates exhaust backpressure or routing (EGR feed, sound, regen support); a malfunction shifts torque mapping and may trigger limp mode.
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
Deactivation solenoid failed
highOne of the most commonly reported causes for this code — check this first.
Wiring break or unplugged connector
mediumA plausible cause — test and verify before replacing parts.
Related help
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