Abstract: A malfunction of a thermostat in a coolant circulating path is detected from an engine side coolant temperature in consideration of the following behavior of the coolant temperature. When an open-malfunction occurs, the coolant temperature becomes different considerably from that in the normal time in the temperature range in which the thermostat is to be normally closed. When a closure-malfunction occurs, the coolant temperature becomes different considerably from that during the normal time in the temperature range in which the thermostat is to be normally opened. Alternatively, the malfunction may be detected from a difference between the engine side coolant temperature and a radiator side coolant temperature.

Abstract: An electrical connection box allows an electrical component mounted in a mounting housing in a rear row to be removed easily from a front side thereof. A plurality of mounting housings are arranged in rows in a central part of a mounting surface of an upper case, with a first plurality of mounting housings provided in a front row and a second plurality of mounting housings provided in a rear row. The mounting housings in the front row are arranged in a lateral direction, with a predetermined interval provided between the adjacent mounting housings. Thus a gap is formed between the adjacent mounting housings arranged in the front row. Through the gap, the tip of a jig may be inserted between the mounting housings in the rear row.

Abstract: An engine control system has a self-diagnosis function of an exhaust system. The self-diagnosis function includes a first mode for detecting a failure or abnormality of the exhaust system as a whole, and a second mode for determining and locating a specific failed component in the exhaust system. The first mode is executed during the engine is operated under a normal condition. Therefore it is possible to detect the failure of the exhaust system without lowering a drive performance or increasing emissions. In case of detecting any failure in the first mode, the second mode is activated in response to a command signal that can be entered via a service tool. In the second mode, the engine is operated in order to determine the failed component. In the second mode, determining the failed component takes priority over keeping the drive performance or reducing emissions.

Abstract: A malfunction of a thermostat in a coolant circulating path is detected from an engine side coolant temperature in consideration of the following behavior of the coolant temperature. When an open-malfunction occurs, the coolant temperature becomes different considerably from that in the normal time in the temperature range in which the thermostat is to be normally closed. When a closure-malfunction occurs, the coolant temperature becomes different considerably from that during the normal time in the temperature range in which the thermostat is to be normally opened. Alternatively, the malfunction may be detected from a difference between the engine side coolant temperature and a radiator side coolant temperature.

Abstract: An emission control system has a catalyst and a sensor responding to a component of exhaust gas. In order to speed warming up the catalyst, the emission control system increases the amount of heat dissipated by exhaust gas. A diagnosis of the emission control system is carried out by determining whether the amount of heat dissipated by exhaust gas is sufficient or insufficient. The amount of heat dissipated by exhaust gas is represented by the length of time to an activated state of the sensor. In the diagnosis, the amount of heat generated by a heater provided in the sensor is taken into consideration. The diagnosis can also be carried out before and after the warming up the catalyst. The heater can also be deactivated. Detection of an abnormality of a secondary air control system can be based on a component of exhaust gas. If the amount of heat dissipated by exhaust gas is found insufficient, additional control can be executed.

Abstract: A malfunction of a thermostat in a coolant circulating path is detected from an engine side coolant temperature in consideration of the following behavior of the coolant temperature. When an open-malfunction occurs, the coolant temperature becomes different considerably from that in the normal time in the temperature range in which the thermostat is to be normally closed. When a closure-malfunction occurs, the coolant temperature becomes different considerably from that during the normal time in the temperature range in which the thermostat is to be normally opened. Alternatively, the malfunction may be detected from a difference between the engine side coolant temperature and a radiator side coolant temperature.

Abstract: A thermostat malfunction detecting system is provided for detecting a malfunction of a thermostat in a coolant circulating path based on an engine side coolant temperature. When an open-malfunction of the thermostat occurs, the coolant temperature becomes considerably different from that normally expected for times at which the thermostat is expected to be closed. When a closure-malfunction occurs, the coolant temperature becomes considerably different from that normally expected for times that which the thermostat is expected to be opened. As an alternative, the malfunction may be detected from the difference from the engine side coolant temperature and the radiator side coolant temperature.

Abstract: An electrical connector housing includes a first shell mountable on a second shell. The first shell is provided with connector mounts to be fit with connectors, fuse mounts to be fit with fuses and relay mounts to be fit with relays. The electrical connector housing contains a busbar stack which includes a connector circuitry module containing connector-connecting circuits, a fuse circuitry module containing fuse-connecting circuits, and a relay circuitry module containing relay-connecting circuits. In this manner, only the busbars contained in the fuse-connecting circuits and those contained in the relay-connecting circuits can be formed of a copper alloy which is harder than pure copper. As a result, the busbar terminals of the fuse-and relay-connecting circuits can be connected directly to the fuse and the relays, respectively. The electrical connector housing thus configured has a simple structure, and can be constructed without increasing costs.

Abstract: Malfunction of an engine coolant thermostat is detected from the engine side coolant temperature by the subsequent behavior of the coolant temperature. When an open-malfunction occurs, the coolant temperature becomes considerably different from that normally expected for times at which the thermostat is expected to be closed. When a closure-malfunction occurs, the coolant temperature becomes considerably different from that normally expected for times at which the thermostat is expected to be opened. Alternatively, the malfunction may be detected from the difference between the engine side coolant temperature and the radiator side coolant temperature.

Abstract: A branch joint box in which after a female connector connected to a wiring harness has been fitted into a male connector provided on the branch joint box, a lock cover provided on the branch joint box is closed and the female connector is locked to the male connector at a fitting position of the female connector by a locking portion of the lock cover, comprising: a temporary retention member for temporarily retaining the lock cover to the branch joint box at a closed position of the lock cover prior to fitting of the female connector into the male connector; a temporary retention cancelling member for cancelling temporary retention of the lock cover in response to fitting action of the female connector into the male connector so as to set the lock cover to an open position of the lock cover; and a fixed retention member which, after the female connector has been fitted into the male connector, not only locks the female connector to the male connector but locks the lock cover to the branch joint box.

Abstract: An internal combustion engine control apparatus is provided which is capable of performing various controls based upon the air quantity immediately after a current heated element of a hot wire air flow meter is heated to a predetermined temperature. When a key switch is rotated to an "ON" position, a large current flows through the air flow meter and the detected intake air quantity greatly exceeds the actual intake air quantity and therefore during the warm up period of the heater, the fuel injection amount is a constant corresponding to the coolant temperature until the engine speed reaches 500 rpm. Likewise during this warm up period, the smoothing processing of the fuel injection quantity is stopped.