Troubleshooting Precautions For Welding On Engines Equipped With Electronic Engine Control Unit (ECU) IMPORTANT: ALWAYS disconnect Electronic Control Unit (ECU) connectors and engine control system-to-machine ground before welding on engine or machine. High currents or electro-static discharge in electronic components from welding may cause permanent damage. 1. Remove the ground connection for the engine control system-to-machine frame. 2. Disconnect the connectors from the ECU. 3. Connect the welder ground close to the welding point and be sure ECU or other electronic components are not in the ground path. OUOD002,000016B –19–08OCT01–1/1 45-2 021604 PN=196