Vehicle Honks for 20 Seconds when Left in Neutral. INFORMATION This is normal vehicle operation if the customer leaves the vehicle (with the key in pocket) in Neutral without being shifted into Park. The honking noise notifies the customer that if the shifter is not put into Park position, the vehicle will roll away or, if left alone for longer periods, have a discharged battery. Please refer to the attached information sheet for further information. Additional information may be found in the Owner's Manual for the vehicle. ATTACHMENTS View PDF attachment M610414_Flyer.