# US 8,769,933 B2 · Method to operate an internal combustion engine

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- Number: US 8,769,933 B2
- Document ID: US8769933B2
- Status: Granted
- Kind: B2
- Application number: 13/237,313
- Filed: 2011-09-20
- Published: 2013-03-21
- Granted: 2014-07-08
- Earliest claimed: 2011-09-20
- Assignees: Detroit Diesel Corporation
- Applicants: Marleen F. Thompson; Tomislav Ivo Golub
- Inventors: Marleen F. Thompson; Tomislav Ivo Golub
- Web page: https://patentgrep.com/patent/US8769933B2

## CPC

- F02D 28/00: Program control of engines
- F02D 41/08: for idling (F02D41/06, F02D41/16 take precedence)
- F02D 41/029: {the exhaust gas treating apparatus being a particulate filter}
- F02D 41/083: {taking into account engine load variation, e.g. air-conditionning}
- F02D: CONTROLLING COMBUSTION ENGINES (vehicle fittings, acting on a single sub-unit only, for automatically controlling vehicle speed B60K31/00; conjoint control of vehicle sub-units of different type or different function, road vehicle drive control systems for purposes other than the control of a single sub-unit B60W)

## Abstract

A method to operate a vehicle equipped an internal combustion engine and a transmission coupled to drive wheels. The vehicle is equipped with a parking brake and has an electronic control unit with memory and the engine in fluid communication with an exhaust aftertreatment system. The method includes the steps of determining whether the engine is operating in idle mode for a predetermined period of time; determining whether NOx emissions exceed a predetermined level after the predetermined period of time; and limiting the engine speed not to exceed a predetermined engine speed until an operator engages the parking brake and engages an engine ignition switch.

## Claims

### Claim 1

A method to operate a vehicle equipped with an internal combustion engine and a transmission coupled to drive wheels; said vehicle further equipped with a parking brake and having an electronic control unit with memory; said engine in fluid communication with an exhaust aftertreatment system; comprising:
determining whether said engine is operating in idle mode for a predetermined period of time;
determining whether NOx emissions exceed a predetermined level after said predetermined period of time;
limiting said engine speed not to exceed a predetermined engine speed until an operator engages said parking brake and engages an engine ignition switch.

### Claim 2 (depends on 1)

The method of claim 1, further including determining whether said engine is operating in Power Take Off Mode (PTO) before determining whether said engine is operating in idle mode for a predetermined period of time.

### Claim 3 (depends on 2)

The method of claim 2, wherein when said engine is operating in PTO mode, the engine continues normal engine operation.

### Claim 4 (depends on 2)

The method of claim 2, further including determining whether said engine is operating in idle for a predetermined period of time after completing PTO mode of operation.

### Claim 5 (depends on 1)

The method of claim 1, further including determining whether said engine is engaged in exhaust aftertreatment regeneration mode before determining whether said NOx emissions exceed a predetermined level.

### Claim 6 (depends on 5)

The method of claim 5, wherein said engine continues in normal operation mode if said engine is operating in exhaust aftertreatment regeneration mode.

### Claim 7 (depends on 5)

The method of claim 5, further including determining whether the NOx emission exceed a predetermined level after exhaust aftertreatment regeneration is complete.

### Claim 8 (depends on 1)

The method of claim 1, wherein said predetermined period of time is calibratable.

### Claim 9 (depends on 1)

The method of claim 1, wherein said NOx emission level is greater than or equal to 30 g.

### Claim 10 (depends on 1)

The method of claim 1, wherein said engine speed is limited to less than or equal to 900 rpm.

### Claim 11 (depends on 1)

The method of claim 1, wherein said engine resumes normal engine operation when said operator engages said parking brake and engages said ignition switch.