Disclosed is a glow plug diagnosis method of being able to diagnose the aging or fault of a glow plug without being affected by cooling associated with air intake/exhaust or fuel injection, the method including: a step (S102) of energizing a glow plug 1 in a predetermined manner when a key switch 11 of a vehicle is turned on; and a step (S106) of measuring the resistance value of the glow plug 1 when the energization of the glow plug 1 is started, and the resistance value of the glow plug when the energization of the glow plug 1 is started and then a change in the resistance value is saturated, and of calculating a change in the resistance value over time as a resistance value gradient, in which it is determined that the glow plug 1 is normal when the resistance value gradient exceeds a predetermined first gradient reference value a, and it is determined that the glow plug 1 is faulty, and a warning lamp or the like is lighted when the resistance value gradient is less than a predetermined second gradient reference value b (S112 and S118).

A method is described for determining the resistance temperature characteristic of a ceramic glow plug, wherein the glow plug is heated at a specified power, wherein before the heating it is first determined whether the glow plug is an aged glow plug, and then, if the glow plug has not been detected as an aged glow plug, the glow plug is heated at a first specified power and the resistance value thereby achieved is assigned to a temperature that is anticipated to be the final temperature when heating a factory-outlet glow plug at this first power, or if the glow plug has been detected as an aged glow plug, the glow plug is heated at a reduced power which is smaller than the first power, and the resistance value achieved thereby is assigned to the same temperature that is also anticipated when heating a factory-outlet glow plug at the first power.

An engine glow plug disconnection detection method may include: increasing, by a controller, temperature of a plurality of glow plugs by performing a rapid temperature increase mode when an engine start signal of a vehicle is recognized by the controller; determining whether the glow plugs are disconnected and the number of disconnections using an engine start early-stage voltage of the vehicle and a voltage of the vehicle when the rapid temperature increase mode is performed, by the controller; recognizing, by the controller, cylinders of an engine with at least a disconnected glow plug upon determining that one or more glow plugs are disconnected: and storing, by the controller, a number of disconnected glow plugs and information related to corresponding cylinders.

The present invention relates to a glow time control device (100) for controlling glow rods (206-209) in a vehicle (200). The glow time control device (100) comprises a control unit (IC1), at least two power transistors (T1, T4) and a protective circuit (T6, T7). The control unit (IC1) comprises a control output (GG1) for emitting a control signal, a supply voltage input (VCC) and a supply voltage output (VDD). The control unit (IC1) provides an output voltage at the supply voltage output (VDD) depending on a voltage at the supply voltage input (VCC). A corresponding glow rod control output (G1, G4) is assigned to each of the power transistors (T1, T4) and the control inputs of the power transistors (T1, T4) are coupled to the control output (GG1). The protective circuit (T6, T7) comprises a protective circuit output which is coupled to the control inputs of the power transistors (T1, T4), and an input which is coupled to the supply voltage output (VDD). The protective circuit adjusts a predefined potential at the protective circuit output if the output voltage of the control unit (IC1) is below a predefined value.

When only smoke is generated, the sensor sensitivity is not substantially changed from the initial value. When both smoke and unburned HC are generated, the number of times the sensor sensitivity becomes lower than the initial value is increased. From these results, it can be understood that a deposit is formed in the presence of unburned HC and smoke existing simultaneously. The degree of reduction in sensor sensitivity becomes higher if the smoke concentration is increased when the unburned HC concentration condition is fixed. From this result, it can also be understood that while the coexistence of smoke and unburned HC is a prerequisite, unburned HC contributes largely to the formation of a deposit.

A control device suitable for use in a vehicle includes a circuit board and a thermal fuse holder including a removable spacer element and a plurality of breaker elements. The thermal fuse holder is attached at a terminal structure and, when the terminal structure is attached to the circuit board, the breaker elements engage the removable spacer element to hold the breaker elements at the circuit board. After terminals of the terminal structure and the breaker elements are soldered at the circuit board, the removable spacer element is removed from the thermal fuse holder, whereby the breaker elements are held at the circuit board via solder joints and are biased away from the circuit board. When the temperature at a respective solder joint exceeds a threshold temperature that melts the solder, the respective breaker element moves away from the circuit board to break the electrical connection at the solder joint.

Disclosed is a control apparatus for controlling power supply from a power source to a glow plug, including a plurality of semiconductor switching elements arranged to turn on and of power supply to the glow plug, a temperature fuse actuated by a temperature rise thereof to interrupt power supply to the semiconductor switching elements, a failure detection portion that detects the occurrence or non-occurrence of an ON failure in each of the semiconductor switching elements, and a control portion that performs drive control of the semiconductor switching elements. When the failure detection portion detects the ON failure in at least one of the semiconductor switching elements, the control portion increases the amount of heat generation of either the at least one of the semiconductor switching elements in which the ON failure is detected or any of the semiconductor switching elements in which the ON failure is not detected.

An engine glow plug disconnection detection method may include: increasing, by a controller, temperature of a plurality of glow plugs by performing a rapid temperature increase mode when an engine start signal of a vehicle is recognized by the controller; determining whether the glow plugs are disconnected and the number of disconnections using an engine start early-stage voltage of the vehicle and a voltage of the vehicle when the rapid temperature increase mode is performed, by the controller; recognizing, by the controller, cylinders of an engine with at least a disconnected glow plug upon determining that one or more glow plugs are disconnected: and storing, by the controller, a number of disconnected glow plugs and information related to corresponding cylinders.

A method for detecting glow plug replacement or an aging glow plug. The glow plugs are heated and monitored. When a threshold value is reached for a first glow plug, a first value of a temperature-dependent variable is measured for all other glow plugs and is stored as reference values associated with the first glow plug. This process is repeated until reference values associated with each glow plug have been determined and stored for each glow plug. The process is repeated to determine a set of comparative values. The comparative values are compared with the reference values. A deviation of a comparative from a reference value of less than a specified tolerance value is considered an agreement. The inventive process concludes which of the glow plugs of the engine are unaltered and which have a resistance-temperature characteristic that has been altered to an extent indicating replacement, aging or a defect.

A control device for the selective control of a multiplicity of actuators of an internal combustion engine is provided. The control device includes a central control unit, and a multiplicity of actuators associated with the multiplicity of actuator controls, which are connected to the central control unit. Each actuator control, of the multiplicity of actuator controls, includes an address, so that the actuator controls are selectively controllable by the central control unit by means of the address. Also, each actuator control includes a comparator, which is configured to compare a signal, preferably a voltage or current signal, emitted by the central control unit with the address. The comparator also emits an activation signal via an activation line, if the comparison has resulted in a match of the signal with the address of the respective actuator control within a window, preferably a voltage window (ΔV).