Ford FOTZ-9F472-E Sensor - Hego

All vehicles fitted with TFI-IV electronic ignition system also have the EEC-IV electronic engine control system, which contains an on board computer referred to as the Electronic Control Assembly (ECA) and other information sensors, which are responsible for monitoring the performance of the engine and feeding the data to the ECA. This data is processed in the ECA and output signals are produced to control intake and exhaust, emissions, fuel control, and driveability. The ECA is housed on the interior of the dashboard, and takes data feed from many sensors such as the Air Charge Temperature sensor, the Engine Coolant Temperature sensor, the Manifold Absolute Pressure sensor, etc which are key to flow of fuel and control of the ignition time. Systems influenced by the ECA are the A/C and cooling fan controller module, fuel injectors, and several solenoids controlling vacuum and fuel operations. The EEC-IV system also has self diagnosis feature whereby the trouble codes are stored in the PCM and can be retrieved for diagnostic purposes. Some of the procedures of changes of sensors including ACT, EVP, ECT, MAP, and EGO consist of the following steps; the first step is to disconnect the battery followed by the removal of the old sensor and replacement with a new one with proper sealing to avoid development of leakage. Putting back the mass air flow sensor which is found in the air intake duct involves some certain procedure that should be followed.

There are two oxygen sensors in the vehicle. One is located before the catalytic converter, and the other, if present, is located under the oil pan in the exhaust pipe.

The TPS monitors throttle angle. It should be checked for proper signal voltage (0.50 to 1.0 volts at idle, 4.0 to 5.0 volts at full throttle) and reference voltage (approximately 5.0 volts). Potentiometer resistance should also be checked (0.8 to 1.0 K ohms at closed throttle, 3.0 to 4.0 K ohms at full throttle).

The TPS monitors throttle angle. It should be checked for proper signal voltage (0.50 to 1.0 volts at idle, 4.0 to 5.0 volts at full throttle) and reference voltage (approximately 5.0 volts). Potentiometer resistance should also be checked (0.8 to 1.0 K ohms at closed throttle, 3.0 to 4.0 K ohms at full throttle).