Service Precautions

Before proceeding with system diagnosis, following precautions must be followed:

• Ensure battery is fully charged and charging system is functional.
• Ensure ignition is off before disconnecting connector from any component.
• When testing voltage or continuity at any electrical component, disconnect connector and check at terminal side of connector. DO NOT backprobe circuit with connector installed unless instructed. DO NOT probe a wire through wire insulation.
• If using a jumper wire, ensure jumper wire is fuse-protected.
• Use care when performing electrical tests, as not to accidentally cause short circuits. Causing a short circuit may cause component damage or set an additional system trouble codes, making diagnosis of original problem more difficult.
• Use scan tool voltmeter or ohmmeter unless instructed to use an external voltmeter or ohmmeter.