CHAMP2: Integrated Cooling Fan Is Noisy Intermittently. INFORMATION Do not replace parts and do not perform a repair attempt! Explain to the customer that this only happens at high ambient temperatures, which keep the fan running after the ignition is turned off. The fan stops running when the head unit enters sleep mode (after approx. 6 minutes). This Service Information will be updated as soon as a solution is available. A software solution is expected to be available with ISTA/P 2.49.0 in March 2013.