What is the process for diagnosing a malfunctioning transfer case or drivetrain component in a four‑wheel drive EMS vehicle?

• A. Replace the transfer case and assume the issue is resolved.
• B. Verify torque and engagement only, ignoring oil level and leaks.
• C. Check transfer case oil level and leaks, verify torque and engagement, perform road test, read OEM diagnostic codes, service as needed.
• D. Ignore diagnostic codes and rely on visual inspection only.

Answer: (C)