Method and system for reducing the time required to power down engine controller with faulty EEPROM

• US 6,347,276 B1
• Filed: 09/13/2000
• Issued: 02/12/2002
• Est. Priority Date: 09/13/2000
• Status: Expired due to Fees

• Current Assignee: Detroit Diesel Corporation (Daimler Truck Holding AG)
• Original Assignee: Detroit Diesel Corporation (Daimler Truck Holding AG)
• Inventors: Avery, Jr., Richard M.
• Primary Examiner(s): WOLFE JR, WILLIS RAY
• Application Number:
  US09/661,141
• Time in Patent Office: 517 Days
• Field of Search: 123/352, 123/436, 123/179.4, 123/198.DB, 701/101, 701/102, 701/103, 701/112, 701/115
• US Class Current: 701/112
• CPC Class Codes: F02D 41/042 for stopping the engine
• CPC Class Codes: F02D 41/22 Safety or indicating devices for abnormal conditions in air/fuel ratio feedback systems F02D41/1495, in electric control linkage F02D11/107, in purge control systems F02M25/0809
• CPC Class Codes: F02D 41/249 Methods for preventing the loss of data

Abstract

A method of limiting engine control delays in an internal combustion engine having an electronic engine controller with an electronically erasable programmable read-only memory (EEPROM) for storing data. A timer and/or a counter may be used to limit re-attempts to write data to the EEPROM upon engine shutdown. If a predetermined time set by the timer for writing to the EEPROM has been exceeded, the system terminates the engine shutdown data write and allows the controller to switch to its low power mode. The counter counts the number of unsuccessful attempts to write to the EEPROM. If the number of unsuccessful attempts to write to the EEPROM exceeds the predetermined number of attempts, the system indicates that there has been a gross failure of the EEPROM and allows the engine control module to be switched to the low power mode. Both a timer and counter may be employed in the system.

Claims

1. A method of limiting engine control delays in an internal combustion engine having an electronic engine controller having an operational mode and a low power mode and having an electronically erasable programmable read only memory (EEPROM) for storing data, wherein the delays are caused by an inability of the EEPROM to store data, comprising:

detecting a shutdown condition when the the engine controller is in the operational mode wherein the engine controller receives a request to shutdown the engine and switch to the low power mode;

enabling a timer set to a predetermined time interval;

writing engine shut down data as required by the engine controller to the EEPROM;

determining whether writing of engine shut down data was completed before the predetermined time interval expires; and

automatically terminating the data write operation if the predetermined time interval expires and switching the engine controller to the low power mode.

2. The method of claim 1 further comprising determining whether the writing step was successful, incrementing a counter each time the writing step is unsuccessful, when the counter exceeds a predetermined number of unsuccessful writing steps generating a fault message that is stored in non-volatile memory and automatically terminating the data write operation and switching the engine controller to the low power mode.

3. The method of claim 1 further comprising logging in a non-volatile memory a fault message indicating that the EEPROM is non-operational.

4. The method of claim 1 wherein the step of writing engine shut down data is performed on blocks of data.

5. A method of limiting engine control delays in an internal combustion engine having an electronic engine controller, the engine having an electronically erasable programmable read only memory (EEPROM) for storing a plurality of sets of engine shut down data, the engine controller having an operational mode and a low power mode, wherein the delays are caused by an inability of the EPROM to store the sets of engine shutdown data comprising:

detecting a shutdown condition when the an engine controller is in the operational mode wherein the engine controller receives a request to shutdown the engine and switch to the low power mode;

writing one of the sets of engine shut down data as required by the engine controller to the pEPROM to create a stored set of engine shut down data;

determining whether the writing step is unsuccessful by comparing the set of engine shut down data to the stored set of engine shut down data, incrementing a outer and determining whether the counter has exceeded a predetermined limit and generating a fault message when the counter exceeds the predetermined number, and if the counter has not exceeded the predetermined number then repeating the writing step, if the counter has exceeded the predetermined number then automatically terminating the data write operation and switching the engine control module to a low power mode; and

determining whether the writing step is successful by comparing the set of engine shut down data to the stored set of engine shut down data, and resetting the counter and determining whether all sets of engine shutdown data have been stored, and if all sets of data have not been stored then repeating the writing step with the next set of engine shutdown data, and if all sets of engine shutdown data have been stored then switching the engine control module to a low power mode.

6. The method of claim 5 further comprising logging in a non-volatile memory the fault message indicating that the BEPROM is non-operational.

7. The method of claim 5 further comprising enabling a timer set to a predetermined time interval;

determining whether writing of engine shut down data was completed before the predetermined time interval expires.

8. A method of providing engine control with engine operation data logging in an EEPROM, comprising:

actuating an ignition switch;

initiating engine controller operation;

enabling engine shut down criteria in the engine controller;

determining whether the ignition switch is turned off and whether engine shut down criteria have been met and generating a signal to stop the engine;

waiting for engine to stop and other ignition off features to be completed;

sending data to EEPROM for writing in EEPROM memory;

determine whether data has been successfully written to the EEPROM;

incrementing a counter when the data is not successfully written to the EEPROM to record a value representative of unsuccessful attempts to write in EEPROM memory;

generating a fault message when the value representative of unsuccessful attempts to write in EEPROM memory exceeds a predetermined value;

storing the fault message in non-volatile memory; and

switching the engine controller to a low power mode.

9. The method of claim 8 further comprising:

initiating a timer that is set to a predetermined time interval after the step of waiting for the engine to stop;

determining whether writing of engine shut down data was completed before the predetermined time interval expires; and

automatically terminating the data write operation and switching the engine controller to a low power mode.

10. A method of controlling an internal combustion engine including an engine controller having an electronically erasable programmable read only memory with a plurality of cells for storing data, and of detecting a gross failure of the memory when the controller attempts to write to the memory upon engine shutdown before entering a low power mode, the method comprising:

detecting an engine shutdown condition wherein the controller receives a request to shutdown the engine and switch to the low power mode;

executing a write command wherein the controller attempts to write a block of data to the memory in a specific block of cells that is stored as a stored block of data;

reading the stored block of data stored in the specified block of cells;

comparing the block of data to the stored block of data

determining whether the stored block of data is the same as the block of data thereby confirming that write command was successful;

determining whether the stored block of data is different from the block of data thereby confirming that write command was unsuccessful and re-executing the write command subject to a re-attempt limit of write commands; and

upon reaching the re-attempt limit of write commands, determining a gross failure of the memory.

11. The method of claim 10 further comprising upon determining a gross failure in memory generating a fault message and storing the fault message in a non-volatile memory.

12. The method of claim 10 further comprising upon determining a gross failure in memory, switching the controller to the low power mode.

13. The method of claim 10 wherein the re-attempt limit is set by a timer set to a predetermined time interval.

14. The method of claim 10 wherein the re-attempt limit is set by a counter that counts the number of failed attempts, and wherein upon reaching a predetermined number of failed write commands, the gross failure of the memory is determined.

15. The method of claim 10 wherein a first re-attempt limit is set by a timer set to a predetermined time delay and a second re-attempt limit is set by a counter that counts the number of failed attempts, and wherein upon reaching either the first re-attempt limit or second re-attempt limit the gross failure of the memory is determined.