Temperature-based emission stability indicator for the transfer of hybrid torques

Abstract

A hybrid automotive system (10) configured to perform torque transmission in a motor vehicle, the system (10) comprising: an internal combustion engine (12) which is configured to operate the motor vehicle in a combustion mode; an electric machine (24) which is set up to operate the motor vehicle in an electric motor mode; a temperature measuring device which is set up to measure an operating exhaust gas temperature of the exhaust gas emitted from the internal combustion engine (12); a control (28) that is set up to: Receiving the operating exhaust gas temperature; Determine whether a temperature criterion is met based on the operating exhaust gas temperature; and Issuance of an emission stability label if the temperature criterion is met; and an actuator configured to perform torque transmission from the electric machine (24) to the internal combustion engine (12) based on the output of the emission stability indicator of the control unit, wherein the control (28) is further configured to: Determining a quantity of the achieved torque transmission readiness based on the operating exhaust gas temperature; Determine whether the amount of torque transmission readiness achieved exceeds a predetermined threshold; and Determine whether the temperature criterion is met, based on whether the amount of torque transmission readiness achieved exceeds the specified threshold. wherein the control (28) is further configured to determine a start-up exhaust gas temperature and an emission-compliant exhaust gas temperature, wherein the amount of torque transmission readiness achieved is further based on the start-up exhaust gas temperature and the emission-compliant exhaust gas temperature, wherein the emission-compliant exhaust gas temperature is a predetermined temperature at which the internal combustion engine (28) does not produce more hydrocarbons than an upper threshold amount of hydrocarbons, wherein the control is further configured to determine whether the motor vehicle is in a cold start emission control mode, wherein the control is configured to determine whether the temperature criterion is met when the motor vehicle is in cold start emission control mode, where the motor vehicle is in cold start emission control mode when the internal combustion engine is operated within a predetermined coolant temperature range.

Description

INTRODUCTION

[0001] The present disclosure relates to the emission-compliant torque transmission from an electric machine to an internal combustion engine in a hybrid vehicle.

[0002] The strategy for reducing cold-start emissions in vehicles is typically implemented under stable engine speeds and load conditions. A hybrid system typically protects the combustion engine for a predetermined period to allow the catalytic converter to warm up sufficiently to efficiently convert hydrocarbons into less harmful compounds. During this cold-start emission reduction strategy, the engine's idle speed and ignition timing are increased, typically for a predetermined duration, such as 10 to 20 seconds. After this predetermined time, the catalytic converter has been deactivated, and oxidation and reduction processes occur. Once the catalytic converter is deactivated, the electric motor can then transfer torque to the combustion engine in a way that minimizes emissions.This is called a protected start.

[0003] Newer powertrain technologies may require torque transfer to the combustion engine before the normal cold-start strategy for emissions reduction is complete. For example, a hybrid system with limited battery capacity for propelling the vehicle may require a very short, protected start. In such cases, the vehicle is expected to utilize the combustion engine to achieve the desired torque before the normal waiting period for the cold-start strategy to reduce emissions has elapsed.

[0004] While current strategies for reducing cold start emissions from vehicles serve their purpose, a new and improved system and procedure is needed to implement faster torque transmission while complying with emissions standards.

[0005] US 2008 / 0078166A1 provides a power system comprising a power source operationally connected to a generator. The power system also includes an exhaust path with at least one aftertreatment device configured to release exhaust gases from the power source into the atmosphere. Furthermore, a controller is configured to determine at least one exhaust path condition based on exhaust gas temperature and to operate the generator accordingly.

[0006] US 8,459,007 B2 describes the modification of combustion parameters in a hybrid vehicle engine to provide an engine power level insufficient to maintain crankshaft rotation at a desired speed. This involves increasing the exhaust gas temperature and reducing the exhaust gas emission content. Additionally, the engine power level is supplemented by the hybrid vehicle's electric motor to maintain crankshaft rotation at the desired speed. A control module includes a cold-start combustion control module that modifies the combustion parameters of a hybrid vehicle engine to provide an engine power level insufficient to maintain crankshaft rotation at a desired speed. This is achieved by increasing the exhaust gas temperature and reducing the exhaust gas emission content.It also includes a control module for the electric machine, which supplements the engine power level with the help of an electric machine from the hybrid vehicle to maintain the crankshaft rotation at the desired speed. DESCRIPTION

[0007] The object of the invention is to minimize the environmental impact of the vehicle while simultaneously maximizing its performance. This object is achieved by the subject matter according to claim 1.

[0008] The present disclosure provides a physical method for determining when torque transmission from the electric machine to the engine can occur in compliance with emissions regulations. It has been found that the degree of exhaust gas temperature increase correlates with the degree of fuel enrichment in the combustion chamber. The temperature increase is an indicator of the amount of raw hydrocarbons produced by the engine. Hydrocarbon production decreases as the engine heats up. By waiting until the engine is sufficiently warm before using engine torque to propel the vehicle, hydrocarbon levels can be kept within emission standards by maintaining the mass airflow through the engine below a certain threshold until hydrocarbon production falls below a specified level.Accordingly, the present disclosure presents a system and method for measuring the temperature of exhaust gases, and the determination of whether torque should be delivered is based on the measured exhaust gas temperature. When the engine is warm enough, the hydrocarbon levels are below an acceptable threshold, and the mass airflow through the engine can be increased without violating emissions standards. Thus, the torque can be transmitted to the engine in an emissions-compliant manner.

[0009] In a form that can be combined or separated with the other forms disclosed herein, a hybrid vehicle system is provided, configured to perform torque transmission in a motor vehicle. The system includes an internal combustion engine configured to power the motor vehicle in a combustion mode and an electric machine configured to power the motor vehicle in an electric motor mode. A temperature measuring device is provided to measure the operating exhaust gas temperature of the exhaust gas emitted by the internal combustion engine. A control unit is provided to: receive the operating exhaust gas temperature; determine whether a temperature criterion is met based on the operating exhaust gas temperature; and output an emission stability indicator if the temperature criterion is met.The system also includes an actuator designed to transfer torque from the electric machine to the internal combustion engine based on the power of the emission stability control system.

[0010] In another form, which can be combined or separated with the other forms disclosed herein, a method for carrying out torque transmission in a motor vehicle is provided. The method includes determining an operating exhaust gas temperature of an internal combustion engine's exhaust gas; determining whether a temperature criterion is satisfied based on the operating exhaust gas temperature; and carrying out torque transmission from an electric machine to an internal combustion engine based on the satisfied temperature criterion.

[0011] In yet another form, which can be combined or separated with the other forms disclosed herein, a control system is provided for implementing torque transmission in a motor vehicle. The control system is configured to: determine whether an operating exhaust gas temperature of an internal combustion engine's exhaust gas has been reached; determine whether a temperature criterion based on the operating exhaust gas temperature has been met; and activate torque transmission from an electric machine to an internal combustion engine based on the achieved temperature criterion.

[0012] Additional features may be provided, including, but not limited to: the control, control system, or method further configured to determine an amount of achieved torque transfer readiness based on the operating exhaust gas temperature, to determine whether the amount of achieved torque transfer readiness exceeds a predetermined threshold, to determine whether the temperature criterion is met based on whether the amount of achieved torque transfer readiness exceeds the predetermined threshold, and / or to determine a start-up exhaust gas temperature and an emissions-compliant exhaust gas temperature. The achieved torque transfer readiness may further be determined based on the start-up exhaust gas temperature and the emissions-compliant exhaust gas temperature.The system may include a catalyst designed to convert hydrocarbons in the exhaust gas into other compounds.

[0013] Further additional functions may be provided, including, but not limited to: the emissions-compliant exhaust temperature being a temperature at which the engine produces no more hydrocarbons than an upper threshold quantity of hydrocarbons; wherein the control, control system, or method is further configured to determine whether the vehicle is in a cold-start emissions control mode; wherein the control, control system, or method is further configured to determine whether the temperature criterion is met when the vehicle is in cold-start emissions control mode; wherein the vehicle is in cold-start emissions control mode when the internal combustion engine is operating within a predetermined coolant temperature range; and wherein torque transmission is initiated in response to the emissions stability indicator.

[0014] Further areas of application will become apparent from the description contained herein. It should be understood that the description and the specific examples serve only for illustration and are not intended to limit the scope of this disclosure. BRIEF DESCRIPTION OF THE FIGURES

[0015] The figures described herein serve only for illustration and are not intended to limit the scope of the present revelation in any way. Fig. Figure 1 is a schematic representation of a hybrid vehicle system according to the principles of the present disclosure; Fig. 2 is a block diagram illustrating a variation of a method for carrying out torque transmission in a motor vehicle according to the principles of the present disclosure; and Fig. Figure 3 is a block diagram illustrating a further variation of a method for carrying out torque transmission in a motor vehicle according to the principles of the present disclosure. DETAILED DESCRIPTION

[0016] The following description of one aspect is merely exemplary and is in no way intended to limit the invention, its application, or use. For clarity, the same reference numerals are used in the drawings to identify identical elements. As used herein, "activated" refers to operation with all engine cylinders. "Deactivated" refers to operation with fewer than all engine cylinders (one or more cylinders inactive). As used herein, the term "processor" refers to an application-specific integrated circuit (ASIC), an electronic circuit, a module (shared, dedicated, or group), and a memory that together execute one or more software or firmware programs, a combinational logic circuit, or other suitable components that provide the described functionality.

[0017] With reference to Fig. A hybrid vehicle system 10 is provided, comprising an internal combustion engine 12 and an electric motor 24, each capable of driving a transmission 14. The transmission 14 can be of any configuration, such as an automatic or manual transmission or a continuously variable transmission (CVT). In combustion mode, the transmission 14 is driven by the engine 12 via a corresponding torque converter or clutch 16. Air flows into the engine 12 through a throttle valve 18. The engine 12 comprises N cylinders 20. In some examples, one or more of the cylinders 20 can be selectively deactivated during engine operation. Fig. While 1 represents eight cylinders (N=8), it should be noted that the engine can contain 12 additional or fewer cylinders 20. For example, engines with 4, 5, 6, 8, 10, 12, and 16 cylinders are considered. Air flows into the engine 12 via an intake manifold 22 and is combusted with fuel in the cylinders 20.

[0018] The electric machine 24 can be operated in both an electric motor mode and a generator mode. In electric motor mode, the electric machine 24 is driven by a battery 26 and drives the gearbox 14. In generator mode, the electric machine 24 is driven by the gearbox 14 and generates electrical energy, which is used to charge the battery 26. The battery 26 can also be used to power other vehicle accessories in addition to the electric machine 24.

[0019] A control unit 28 communicates with the motor 12 and the electric machine 24 and can receive various inputs from exhaust gas parameter measuring devices, such as sensors, as described herein. A driver operates an accelerator pedal 30 to control the throttle valve 18. Specifically, a pedal position sensor 32 generates a pedal position signal that is transmitted to the control unit 28. Based on the pedal position signal, the control unit 28 generates a throttle valve control signal. A throttle valve actuator (not shown) adjusts the throttle valve 18 based on the throttle valve control signal to regulate the airflow into the motor 12.

[0020] The driver also operates a brake pedal 34 to control the vehicle's braking. When the brake pedal 34 is operated, a brake position sensor 36 generates a brake pedal position signal, which is transmitted to the controller 28. The controller 28 generates a brake control signal based on the brake pedal position signal. A braking system (not shown) adjusts the vehicle's braking based on the brake control signal to control the vehicle's speed. In addition to the pedal position sensor 32 and the brake position sensor 36, an engine speed sensor 38 generates a signal based on the engine speed. An intake manifold absolute pressure (MAP) sensor 40 generates a signal based on the intake manifold pressure 22. A throttle position sensor (TPS) 42 generates a signal based on the throttle position.An air mass flow sensor (MAF) 44 generates a signal based on the airflow into the throttle 18. A fuel mass flow sensor 58 can also be provided.

[0021] If the vehicle load requirements can be met with torque generated by fewer than all cylinders 20, the controller 28 switches the engine 12 to deactivated mode. In an exemplary embodiment, N / 2 cylinders 20' are deactivated, with the option to deactivate one or more cylinders 20'. When the selected cylinders 20' are deactivated, the controller 28 increases the power output of the remaining cylinders 20' by adjusting the position of the throttle 18. The engine load is determined based on inputs such as MAP, MAF, RPM, and others. For example, if an engine vacuum at a given speed exceeds a threshold, the engine load can be supplied by fewer than all cylinders, and the engine 12 operates in deactivated mode.If the vacuum is below a second threshold for the given rotational speed, the engine load cannot be provided by fewer than all cylinders, and engine 12 will operate in activated mode.

[0022] Control unit 28 provides engine speed control to adjust engine output torque by adjusting intake air / fuel mixture and ignition timing to maintain a target engine speed. Control unit 28 provides an electronic spark timing (EST) signal, which is output via line 46 to an ignition control unit 48. The ignition control unit 48 responds to the EST signal to provide a timed output of the drive signals to the spark plugs 50 for combustion of the fuel charge in the engine cylinders 20. The EST signal can also provide spark timing signals over a wide time range. Normally, it is desirable for the ignition timing to occur before top dead center of the piston, and as engine speed increases, it is typical to advance the ignition timing further.

[0023] In some cases, ignition may occur after top dead center. The ignition timing can be retarded, for example, to quickly limit engine output torque or, during cold starts, to increase exhaust temperature—essentially by trading engine output torque for heat.

[0024] The exhaust gas flow from the engine 12 passes through at least one catalyst 52 with a catalyst 54, which is required to reach a predetermined temperature (defined as "catalyst deactivation") before its oxidation and reduction reactions are carried out optimally. The ignition timing can be retarded during cold starts of the engine to raise the exhaust gas temperature more quickly and thus increase the temperature of the catalyst 54 as quickly as possible, thereby achieving fuel emission standards more rapidly. The predetermined temperature-determining catalyst deactivation can be stored in a memory 59 of the control unit 28.

[0025] As a further method for raising the temperature of the catalyst 54 during the cold start of the engine, an “increased idle speed” can be implemented, whereby the control unit 28 signals a temporarily increased engine idle speed above the normal engine idle speed. The increased idle speed can last for a period of approximately 10 to 40 seconds after the engine starts. A predefined target is used to control the engine speed and the ignition timing or delay during increased idle operation.

[0026] During certain operating periods, the entire time available for performing an increased idling may not be available. For example, if the vehicle is accelerating using the electric motor 24 powered by the battery 26 to drive the transmission 14, but the torque is insufficient to meet the torque requirement, an engine start and torque delivery may be necessary before the catalyst 54 can reach the minimum temperature required for catalyst deactivation. Under such conditions, it is desirable to continue meeting emissions standards while maintaining the engine speed to meet the torque requirement.

[0027] However, if possible, it is desirable to quickly transfer the torque of the electric machine 24 to the engine 12 as soon as the amount of hydrocarbons ultimately emitted falls below a threshold sufficient to meet the emission standards. To determine when such torque transfer from the electric machine 24 to the engine 12 can occur while complying with the emission standards, one or more exhaust gas temperature sensors 56 can be used, which can be positioned either upstream or downstream, or both upstream and downstream, of the catalyst 52.

[0028] With reference to Fig. 2 and with continued reference to Fig. Figure 1 is a high-level version of a method for performing a hybrid torque transmission from the electric machine 24 to the motor 12, and is generally designated 100. Method 100 can be implemented by the controller 28 or another controller or combination of controllers to implement torque transmission within the hybrid vehicle system 10. Method 100 includes a step 102 for determining an operating exhaust gas temperature of the exhaust gas from the motor 12. For example, the temperature sensor 56 can be used to measure the exhaust gas temperature in the exhaust pipe 60, which extends from the motor 12 through the catalyst 52. In other variations, the exhaust gas temperature could be estimated using other parameters, as opposed to direct measurement.

[0029] Procedure 100 further includes a step 104 for determining whether a temperature criterion is met based on the operating exhaust gas temperature. Generally, the engine emits fewer hydrocarbons and less than a hydrocarbon threshold to meet emission standards when the exhaust gas has relatively higher temperatures and / or rises at a lower rate. The exhaust gas temperature depends on a variety of factors, such as the ambient temperature and the duration of driving or parking before starting. Therefore, the amount of hydrocarbons produced can be predicted based on the exhaust gas temperature, but the time required to warm the exhaust gas sufficiently varies. A model of hydrocarbon production as a function of the operating exhaust gas temperature can, for example, be incorporated into control 28.Accordingly, the operational readiness of the exhaust system for torque transmission is determined based on the operating exhaust gas temperature.

[0030] The procedure 100 then includes a step 106 to perform a torque transmission from the electric machine 24 to the internal combustion engine 12 based on the temperature criterion being met.

[0031] With reference to Fig. 3, with further reference to Fig. Figure 1 presents a more detailed version of a method for carrying out a hybrid torque transmission from an electric machine 24 to a motor 12, and is generally referred to as 200. As with method 100, method 200 can be implemented by the controller 28 or another controller or combination of controllers to realize torque transmission within the hybrid vehicle system 10.

[0032] The procedure includes step 210 for collecting parametric data to determine whether the vehicle's hybrid automotive system 10 is in Cold Start Emission Control (CSEC) mode. For example, the collected data may include engine speed and ignition timing. In step 212, procedure 200 includes determining whether the vehicle is in CSEC mode. In some examples, the vehicle or hybrid system 10 can be determined to be in CSEC mode if the internal combustion engine 12 operates within a specified coolant temperature range. In some cases, CSEC mode can also be implemented within specific ranges of a given catalyst temperature (e.g.,based on estimating the catalyst temperature using other measured parameters), or when the engine 12 is operated below a predetermined engine speed, such as 1500 rpm, and / or within a predetermined ignition angle range, such as less than -10 degrees. The ignition angle range is the point at which the spark occurs in the combustion chamber relative to top dead center. CSEC mode is a condition in which the catalyst 52 is at a temperature below that required for catalyst deactivation, e.g., when the catalyst 52 is at ambient temperature.

[0033] If the vehicle's hybrid system 10 is not in CSEC mode, the engine 12 is already warm, and procedure 200 follows path 214 back to block 210 to collect more data and determine again whether the vehicle is in CSEC mode. However, if the vehicle is in CSEC mode, procedure 200 continues along path 216 to step 218.

[0034] In step 218, the procedure 200 involves determining an operating exhaust gas temperature, for example using the temperature sensor 56. The procedure 200, or the control system, then proceeds to a step 224, which involves calculating a percentage of the achieved torque transmission readiness; in other words, the amount of torque transmission readiness indicates how ready the hybrid system is to transmit torque to the engine 12, based on the amount of hydrocarbon emissions emitted from the engine 12, the amount of hydrocarbon emissions being approximately known based on the determined operating exhaust gas temperature.

[0035] In one example, several inputs are used to calculate the percentage of torque transmission readiness achieved. For instance, the percentage of torque transmission readiness achieved is calculated from the operating exhaust gas temperature determined in step 218. Furthermore, procedure 200, as represented by step or block 220, involves determining an initial exhaust gas temperature, which can be determined at engine start-up 12. Thus, step 220 represents a data point of temperature information measured at an earlier time but inputted to step or module 224. Another contribution to the calculation of the percentage of torque transmission readiness achieved is an emissions-compliant exhaust gas temperature, which can be determined in block or step 223 and provided to block or step 224.The emission-compliant exhaust gas temperature is a temperature at which the engine 12 produces no more hydrocarbons than an upper threshold quantity. The emission-compliant exhaust gas temperature can, for example, be pre-programmed or calibrated in the control unit 28. Thus, in this example, block or step 224 can determine the percentage of achieved torque transmission readiness using the following equation: Percentage of achieved torque transmission readiness = TC−T0TH−T0∗100% where T C T0 is the operating (or current) exhaust gas temperature, T0 is the initial exhaust gas temperature, and T H The emission-compliant exhaust gas temperature is therefore determined. Thus, method 200 includes determining the amount of torque transmission readiness achieved based on the operating exhaust gas temperature T. C, and determining the amount or percentage of the achieved torque transmission readiness can further be based on the initial exhaust gas temperature T0 and the emission-compliant exhaust gas temperature T H take place.

[0036] Procedure 200 then proceeds to step 226 to determine whether the amount of torque transmission readiness achieved exceeds a predetermined threshold. Step 226 may also include determining whether the temperature criterion is met, based on whether the amount of torque transmission readiness achieved exceeds the predetermined threshold.

[0037] If the amount of torque transmission readiness achieved does not exceed the specified threshold, procedure 200 follows path 228 back to step 210. However, if the amount of torque transmission readiness achieved reaches or exceeds the specified threshold, procedure 200 continues with path 230 to step 234. In the example of Fig. 3. Determining whether the temperature criterion is met is only performed if the vehicle is in Cold Start Emission Control (CSEC) mode, as determined in step 212. Procedure 200 may also include issuing an Emission Stability Label if the temperature criterion is met, and then proceeding to step 234.

[0038] In step 234, procedure 200 involves initiating a torque transmission from the electric machine 24 to the internal combustion engine 12 based on the achieved temperature criterion. If the emission stability indicator is used, step 234 is initiated to perform the torque transmission in response to the emission stability indicator.

[0039] The system and method disclosed herein for carrying out a hybrid torque transmission offers several advantages. These include the ability to transfer the torque according to the conditions, instead of using a predetermined waiting time, which accelerates the torque transmission under certain conditions.

[0040] The present system and method is physically constructed and can use a model to project the performance of hydrocarbon emissions as a function of the operating exhaust gas temperature, thereby enabling an appropriate torque transmission to the internal combustion engine 12 based on the operating exhaust gas temperature.

[0041] The controller 28 is a control system with one or more controllers and may include a computer-readable medium (also called a processor-readable medium), including any non-volatile (e.g., physical) media involved in providing data (e.g., instructions) that can be read by a computer (e.g., by a computer's processor). Such a medium can take many forms, including, but not limited to, non-volatile and volatile media. Non-volatile media may include, for example, optical or magnetic disks and other persistent storage devices. Volatile media may include, for example, dynamic random-access memory (DRAM), which can represent main memory.These instructions can be transmitted through one or more transmission media, including coaxial cable, copper wire, and fiber optic cable, including the wires comprising a system bus coupled to a computer's processor. Examples of computer-readable media include a floppy disk, a flexible disk, a hard disk, magnetic tape, any other magnetic medium, a CD-ROM, a DVD, another optical medium, punched cards, paper tape, another physical medium with hole patterns, RAM, a PROM, an EPROM, a FLASH EEPROM, another memory chip, or a cartridge or other medium from which a computer can read.

[0042] Lookup tables, databases, data stores, or other data repositories described herein may include various types of mechanisms for storing, accessing, and retrieving different kinds of data, including a hierarchical database, a set of files in a file system, an application database in a proprietary format, a relational database management system (RDBMS), and so on. Each of these data stores can be integrated into a computer device using a computer operating system such as one of those mentioned above and can be accessed over a network in one or more of the most varied ways. A file system can be accessed from a computer operating system and may contain files stored in various formats.An RDBMS can use the Structured Query Language (SQL) in addition to a language for creating, storing, editing and executing stored procedures, such as the PL / SQL language mentioned above.

[0043] The description of the present revelation is merely exemplary, and any deviations that do not deviate from the core of the present revelation are considered to be within the scope of the present revelation. The various examples given can be combined in different ways without limiting the spirit and scope of the present revelation.

Claims

[1] A hybrid automotive system (10) configured to perform torque transmission in a motor vehicle, the system (10) comprising: an internal combustion engine (12) which is configured to operate the motor vehicle in a combustion mode; an electric machine (24) which is set up to operate the motor vehicle in an electric motor mode; a temperature measuring device which is set up to measure an operating exhaust gas temperature of the exhaust gas emitted from the internal combustion engine (12); a control (28) that is set up to: Receiving the operating exhaust gas temperature; Determine whether a temperature criterion is met based on the operating exhaust gas temperature; and Issuance of an emission stability label if the temperature criterion is met; and an actuator configured to perform torque transmission from the electric machine (24) to the internal combustion engine (12) based on the output of the emission stability indicator of the control unit, wherein the control (28) is further configured to: Determining a quantity of the achieved torque transmission readiness based on the operating exhaust gas temperature; Determine whether the amount of torque transmission readiness achieved exceeds a predetermined threshold; and Determine whether the temperature criterion is met, based on whether the amount of torque transmission readiness achieved exceeds the specified threshold. wherein the control (28) is further configured to determine a start-up exhaust gas temperature and an emission-compliant exhaust gas temperature, wherein the amount of torque transmission readiness achieved is further based on the start-up exhaust gas temperature and the emission-compliant exhaust gas temperature, wherein the emission-compliant exhaust gas temperature is a predetermined temperature at which the internal combustion engine (28) does not produce more hydrocarbons than an upper threshold amount of hydrocarbons, wherein the control is further configured to determine whether the motor vehicle is in a cold start emission control mode, wherein the control is configured to determine whether the temperature criterion is met when the motor vehicle is in cold start emission control mode, where the motor vehicle is in cold start emission control mode when the internal combustion engine is operated within a predetermined coolant temperature range.

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