OBD Code P0643

Sensor Reference Voltage “A” Circuit High

What’s mean?

OBD2 Code P0643 Definition:
The ECM has detected that the 5 volt reference voltage is too high

Symptoms

Possible sumptoms of P0643
– Engine Light ON (or Service Engine Soon Warning Light)

Possible Causes

Possible causes of P0643
– ECM Short circuit condition – Shorted sensor on 5 volt circuit – Failed ECM

Possible Solutions