Faulty Hood Ajar Switch
Hood Ajar Switch harness is open or shorted
Hood Ajar Switch circuit poor electrical connection
Faulty Engine Control Module (ECM)
Engine Light ON (or Service Engine Soon Warning Light)
The Engine Control Module (ECM) applies 5 V to the hood ajar signal circuit and monitors the voltage to determine the position of the hood. The hood ajar switch contains a multiplexed resistor. This resistor will vary the voltage seen by the Engine Control Module by pulling down the applied voltage based on the position of the switch. The Diagnostic Trouble Code (DTC) will be set when the Engine Control Module detects a short to ground in the hood ajar signal input to the Engine Control Module.