Code result
P0540
Intake Air Heater Circuit Malfunction
Moderate severity
What it means
Intake Air Heater A Circuit: an electrical fault is present in the circuit. Used on diesel and some petrol engines for cold-start emissions and starting reliability.
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
Heater element open or shorted
highOne of the most commonly reported causes for this code — check this first.
Heater relay defective
mediumA plausible cause — test and verify before replacing parts.
Wiring fault
lowLess common, but worth ruling out after the more likely causes.
Related help
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