🔍 Key Concepts

• Follow the trouble analysis chart from the specific fault code number, not from general intuition. • Differentiate between checking the speed log signal source (what data is coming from the log) and checking the wiring/connections that carry that signal. • For electronics troubleshooting, exams usually expect you to start with the simplest, non‑invasive checks before replacing assemblies.

💭 Think About

• On the trouble analysis flowchart for fault code 42, what is the very first decision box or action step mentioned? Does it reference the data coming from the log, or the cabling/terminals? • In the faults table, how is fault 42 (SPEED LOG ERROR) described—does it point you to verify the input signal, or to a specific hardware module? • Among the options given, which one represents a basic check you can do before swapping any circuit boards or assemblies?

✅ Before You Answer

• Verify exactly what the first step for fault code 42 is in Illustration EL‑0197/EL‑0198—don’t skip ahead to later steps. • Confirm whether the chart tells you to inspect/verify an external signal (log output/data strings) before touching internal units like the CPU or DC/DC assemblies. • Make sure the action you pick is a diagnostic check, not a replacement, unless the chart clearly shows replacements only after initial checks.