P06A6 — Sensor Reference Voltage A Circuit Range or Performance
The 5-volt sensor reference rail A 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 A then reports skewed readings, which can trigger secondary faults. Causes: a partial short or high resistance on the reference-A circuit, an overloaded rail caused by a shorted sensor, or an internal regulator fault in the module.
General code reference. Confirm the definition and diagnostic procedure for your vehicle's year, model and engine. A stored code alone does not identify a failed part.
Affected components
- Sensor reference voltage a
Possible causes to check
These are possible checks, not a ranked diagnosis. Follow the vehicle manufacturer's test procedure before replacing parts.
- Reference rail drifted
Possible symptoms
- Check engine light on
- Possible limp mode or no-start
- Multiple follow-up faults across modules
- Reset/relearn may be needed after repair
Diagnostic notes
- The malfunction indicator lamp may illuminate
- This code can affect emissions
Related codes
Sources
Check each reference's vehicle and model-year scope. General background links do not establish which fault is most likely on your vehicle.
Diagnostic information is provided for reference only. Confirm the code with a compatible scan tool and follow the vehicle manufacturer's service procedures before replacing components.