Service Precautions

Before proceeding with system diagnosis, observe service precautions as follows:

• 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 otherwise 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 diagnostic trouble code(s), making diagnosis of original problem more difficult.
• Use scan tool voltmeter or ohmmeter unless instructed to use an external voltmeter or ohmmeter.