Service Precautions
CAUTION:
Always turn ignition switch to OFF position before disconnecting any control module connector or battery. When battery is disconnected, vehicle computer and memory systems may lose memory data. Driveability problems may exist until computer systems have completed a relearn cycle. See COMPUTER RELEARN PROCEDURES article in GENERAL INFORMATION before disconnecting battery.
Before proceeding with TROUBLE SHOOTING, SELF-DIAGNOSTIC SYSTEM, or SYSTEM TESTS, the following precautions must be followed:
- Vehicle must have a fully charged battery and functional charging system.
- Always start at RETRIEVING & CLEARING DIAGNOSTIC TROUBLE CODES under SELF-DIAGNOSTIC SYSTEM. Starting with any other test may result in incorrect results.
- Only perform test steps indicated. It is NOT necessary to perform all steps in a test.
- Turn ignition switch to OFF position before disconnecting any module, or before connecting components.
- Use extreme care when connecting or disconnecting components during testing to prevent accidental grounding or shorting.
- DO NOT use a test light in place of a DVOM, unless instructed otherwise.
- Always disconnect scan tool after use or when disconnecting/charging battery.
- Always perform appropriate verification test after repairs are made. See VERIFICATION TEST .