Possible causes

– Faulty Engine Control Module (ECM)
– ECM harness is open or shorted
– ECM circuit poor electrical connection
– Shorted sensor on 5 volt circuit

When is the code detected?

The Engine Control Module (ECM) has detected the sensor 5 volt reference circuit voltage is higher than expected

Symptoms

– Engine Light ON (or Service Engine Soon Warning Light)

P0643 Information for specific makes

P0643 AUDI
P0643 CHRYSLER
P0643 DODGE
P0643 FORD
P0643 HYUNDAI
P0643 INFINITI
P0643 ISUZU
P0643 JEEP
P0643 KIA
P0643 MITSUBISHI
P0643 NISSAN
P0643 SUZUKI
P0643 VOLKSWAGEN