Code result
P0641
Sensor Reference Voltage \"A\" Circuit Open
High severity
What it means
The 5 V reference voltage that the ECU supplies to multiple sensors (TPS, MAP, accelerator pedal, etc.) has dropped out or is open-circuit. Symptoms cascade — many sensor codes appear at once, all related to the same reference rail.
Is it safe to drive?
No — stop driving
This code can put the vehicle into limp or reduced-power mode. Avoid extended driving and have the vehicle diagnosed promptly.
Most likely causes
Reference wire shorted to ground (one defective sensor pulls the rail down)
highOne of the most commonly reported causes for this code — check this first.
ECM internal reference output failed
mediumA plausible cause — test and verify before replacing parts.
Pin pushed back out of connector body
lowLess common, but worth ruling out after the more likely causes.
Related help
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