Customer Concern: Tests/Procedures: Potential Causes: Tech Tips: Trouble code P2626. 1. At the Air/Fuel Ratio (A/F) sensor, check to see if there is battery voltage to the sensor key on engine off on the White wire. Battery voltage should also be present on the Yellow/Orange wire key on. 2. Check to see if the Engine Control Module (ECM) grounds the Yellow/Orange wire on start up. 3. Check the resistance of the A/F sensor heater circuit. Normal resistance is 2.2- 2.9 ohms. 4. Check the remaining wires for shorts to ground or each other. 5.Follow Hyundia TSB # 03-36-014-01 for further testing. Air Fuel Ratio (AFR) Sensor Harness An A/F sensor would not be an uncommon problem.