N55: Engine Difficult to Start at Cold Ambient Temperatures. The complaint may include any of the following symptoms: * The engine stalls immediately after a cold start before driving away * The engine may run roughly or misfire after a cold start * The engine does not start cold or may take several attempts * To assist starting when cold, the accelerator may need to be depressed slightly and the idle speed raised for a few seconds so the engine does not stall This can occur most frequently at outside ambient temperatures between -15°C and + 15°C. It is possible that the Service Engine Soon (MIL) lamp is on with misfire fault(s) stored, but it is equally possible that there will be no faults stored in the DME. Unfavorable DME software Cold start or idling problems may arise due to poor fuel quality. The use of summer fuel during cold outside temperatures may also lead to such problems.