P06A9
Sensor Reference Voltage D Circuit Range or Performance
What it means
The 5-volt sensor reference rail D is electrically connected but its voltage is out of tolerance — drifting, sagging under load, or noisy instead of a stable 5.00 V. Every sensor fed from reference D then reports skewed readings, which can trigger secondary faults. Causes: a partial short or high resistance on the reference-D circuit, an overloaded rail caused by a shorted sensor, or an internal regulator fault in the module.
Is it safe to drive?
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
Reference rail drifted
highOne of the most commonly reported causes for this code — check this first.
Related help
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