Engine variable oil pump diagnostic method

Patent metadata

Field	Value
Publication number	US-10865670-B2
Application number	US-201715792693-A
Country	US
Kind code	B2
Filing date	Oct 24, 2017
Priority date	Oct 24, 2017
Publication date	Dec 15, 2020
Grant date	Dec 15, 2020

Abstract

Methods and systems are provided for indicating degradation of a variable displacement oil pump. In one example, an engine method comprises indicating degradation of the oil pump based on a fuel usage change of the engine, responsive to a commanded change in displacement of the variable oil pump. In response to an indicated degradation, engine wear may be avoided and fuel economy may be improved by adjusting engine operation.

First claim

The invention claimed is:

1. A method for an engine of a vehicle, comprising:
indicating a variable displacement oil pump is stuck in a low displacement mode based on a change in fuel economy of the engine being less than a threshold change following a commanded change in displacement of the oil pump, and further based on an average fuel economy following the commanded change in displacement being substantially equal to a baseline fuel economy; and
increasing a commanded engine idle speed based on the indication that the oil pump is stuck in the low displacement mode.

2. The method of claim 1 , wherein the commanded change in displacement occurs during first vehicle operating conditions that comprise vehicle speed above a threshold vehicle speed and one or more of engine speed and engine load changing by less than a respective threshold amount, and wherein the baseline fuel economy is determined prior to the commanded change in displacement while the vehicle is operating with the first vehicle operating conditions.

3. The method of claim 2 , further comprising commanding the change in displacement of the oil pump by deactivating a solenoid of the oil pump, the solenoid configured to displace a spring when activated, the spring causing one or more internal rotors of the oil pump to pivot when displaced by the solenoid, and wherein the baseline fuel economy is determined while the solenoid of the oil pump is activated.

4. The method of claim 3 , further comprising, upon indicating that the oil pump is stuck in the low displacement mode, maintaining the solenoid deactivated even when vehicle speed is above the threshold vehicle speed, and further comprising indicating that the oil pump is not degraded responsive to the change in fuel economy of the engine being more than the threshold change following the commanded change in displacement of the oil pump.

5. The method of claim 1 , wherein the commanded engine idle speed comprises an engine speed the engine is controlled to operate at when the engine is operating and the vehicle is not propelled by the engine.

6. The method of claim 1 , further comprising indicating that the oil pump is stuck in a high displacement mode based on the change in fuel economy of the engine being less than the threshold change following the commanded change in displacement of the oil pump, and further based on the average fuel economy following the commanded change in displacement being less than the baseline fuel economy.

7. The method of claim 1 , further comprising notifying an operator and/or setting a diagnostic code based on the indication that the oil pump is stuck in the low displacement mode.

8. The method of claim 1 , wherein increasing the commanded engine idle speed comprises adjusting one or more of an idle throttle and an intake throttle to a more-open position during engine idle conditions.

Assignees

• Ford Global Tech Llc

Inventors

• Dudar Aed M

Classifications

• F01M1/18 Primary

  Indicating or safety devices (concerning lubricant level F01M11/06, F01M11/12) · CPC title

• F01M2001/0238

  Rotary pumps · CPC title

• F01M2250/60

  Operating parameters · CPC title

• F01M1/02 Primary

  using lubricating pumps (pumps in general F04; lubricating pumps per se F16N) · CPC title

• F01M2001/0246

  Adjustable pumps · CPC title