Possible causes

– Faulty Transmission Gear Selection Switch
– Transmission Gear Selection Switch harness is open or shorted
– Transmission Gear Selection Switch circuit poor electrical connection

Symptoms

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

P0816 Information for specific makes

P0816 DODGE
P0816 ACURA
P0816 HONDA
P0816 MITSUBISHI
P0816 CHRYSLER
P0816 JEEP