A hot-only slow crank requires a comparison under both temperature conditions. A satisfactory cold test may not reproduce the fault that prevents a restart after a journey.
Plan the test window
Tell the workshop journey duration and how long the vehicle must stand before restarting normally. Include oil or mechanical work, battery history and any supply measurements. Distinguish slow physical cranking from normal-speed cranking that fails to fire.
Do not keep attempting starts until components overheat. A technician should consider electrical and mechanical causes under the actual hot condition before recommending an ECU. Ask the report to state what was tested hot and what remains uncertain if the symptom could not be recreated.
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