What Does P0640 Mean? This means that a voltage that exceeds the level stipulated by the manufacturer hasoccurred. Usually, your Check Engine Light will come on, although sometimes the codehas to be recorded three times before this happens. engine code P0640P0640 fixobd P0640dtc P0640obd code P0640obd2 P0640P0640 car codediagnostic code P0640car code P0640check engine code P0640fehlercode P0640P0640 fiatcodigo P0640codigo falla P0640P0640 kody b??dówcodigo de falla P0640 What are the common causes of P0640 ? Technicians report the most common cause of this code being a faulty intake air heater relay. Other causes may include shorted or open wiring or connectors, a burnt out heater element, a bad intake air heater blower, a faulty or disconnected intake air temperature sensor, or a faulty PCM. PCM failure is rare. How do you troubleshoot P0640 ? Deactivation of cylinders is achieved by releasing a synchroniser pin that normally interlocks the cam follower and rocker arms. P0640 code resolves the synchroniser pin is released using hydraulic pressure which is controlled by a dedicated solenoid. Searches related to P0640 - Intake Air Heater 'A' Control Circuit p0640 7.3 powerstroke p0541 p0460 p0641