In some cars, however, the problem could be solved by reprogramming the engine computer (PCM) with an updated software. See common problems below. An Engine Coolant Temperature ( ECT) sensor monitors the temperature of the coolant. The air flow coming into the engine is accumulated and used to determine if the vehicle has been driven within.
The Engine Control Module (ECM) determines this length of time based on ambient temperature. The powertrain control module (PCM) tracks how long it takes for the engine of a vehicle to reach and maintain the correct operating temperature. When the correct engine operating temperature is reache the powertrain control module orders the fuel system to enter “closed loop” where readings from the oxygen sensors are used.
Experience: Ase Master Certifie GM Master Certified Tech. Hello, code PO1is for thermostat. An engine coolant temperature (ECT) sensor monitors the temperature of the coolant. Leaking or stuck open thermostat. In other words the engine is running too cold – or at least the PCM thinks it is.
L engines where the temperature gauge stays on COL but the cooling fans are on. Faulty intake air temperature (IAT) sensor. Fault codes that can be triggered due to engine coolant thermostat failures.
Mercedes thermostat part numbers.