Sensor Reference Voltage "A" Circuit High
5 V reference rail A above threshold — short to a higher voltage source. Wiring faults of this kind typically come from chafing, water ingress at connector seals, or pin push-back — a wiggle test on the harness while the code is active often confirms the location.
Affected components
- Sensor reference circuit
- Ecu
Common causes
- High likelihood: Sensor or harness shorted to higher voltage
- Low likelihood: Connector pins corroded - high contact resistance
- Low likelihood: Supply wire pinched against B+ source
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
- Reduced-power or limp mode may occur
Related codes
Sources
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.