Service Precautions

For safety during road test, it is advisable to have a helper operate tester from rear seat. If test and measuring instruments are operated from front passenger's seat and vehicle is involved in an accident, there is a possibility the person sitting in this seat may receive serious injuries when air bag is deployed. WARNING: Turbocharger and related components operate at a very high temperature. Always allow system to cool or use proper protective clothing to prevent severe burns. Read and record DTCs before starting diagnostic work, (some testing procedures will set DTCs). Turn ignition off before connecting or disconnecting test equipment, unless specifically instructed not to do so in repair instructions. Turn ignition off before connecting or disconnecting Electronic Control Module (ECM), (J220) connectors. Perform all resistance and voltage tests with a Digital Volt-Ohmmeter (DVOM) with minimum 10-megohm impedance, unless stated otherwise in test procedures. Ensure ignition switch is in OFF position when performing resistance tests. Remove fuel pump fuse No. 17 (15-amp) before opening fuel system. Fuel hoses in engine compartment must only be secured by spring type clips. When performing an ignition spark test, check one spark plug at a time and ensure spark plug is grounded. When performing compression test, remove fuel pump fuse No. 17 (15-amp) and disconnect connectors from ignition coils. See COMPRESSION TEST under MECHANICAL INSPECTION in BASIC DIAGNOSTIC PROCEDURES article.