Systems and methods for diagnosing a vehicle fuel system and evaporative emissions control system
First Claim
1. A method comprising:
- setting an initial vent duration for an engine-off-natural-vacuum test for a vehicle based on a set of engine-off-natural-vacuum test results retrieved from a plurality of other vehicles;
commencing the engine-off-natural-vacuum test with a vacuum phase portion when it is determined that the vehicle can pass during the vacuum phase portion based on the retrieved set of engine-off-natural-vacuum test results from the plurality of other vehicles; and
commencing the engine-off-natural-vacuum test with a pressure phase portion when it is determined that the vehicle can pass during the pressure phase portion based on the retrieved set of engine-off-natural-vacuum test results from the plurality of other vehicles.
1 Assignment
0 Petitions
Accused Products
Abstract
Methods and systems are provided for conducting an engine-off-natural-vacuum (EONV) test diagnostic on a vehicle fuel system and evaporative emissions system. In one example, a method may include setting an initial vent duration for the EONV test as a function of a likelihood that the vehicle will pass the EONV test during a pressure phase portion, or during a vacuum phase portion, and commencing the EONV test with the vacuum phase portion responsive to the likelihood that the vehicle will pass during the vacuum phase portion. In this way, battery power may be conserved and fuel economy improved, by avoiding a pressure phase portion of the EONV test if it is indicated that the vehicle is not expected to pass the EONV test during the pressure phase portion.
43 Citations
19 Claims
-
1. A method comprising:
-
setting an initial vent duration for an engine-off-natural-vacuum test for a vehicle based on a set of engine-off-natural-vacuum test results retrieved from a plurality of other vehicles; commencing the engine-off-natural-vacuum test with a vacuum phase portion when it is determined that the vehicle can pass during the vacuum phase portion based on the retrieved set of engine-off-natural-vacuum test results from the plurality of other vehicles; and commencing the engine-off-natural-vacuum test with a pressure phase portion when it is determined that the vehicle can pass during the pressure phase portion based on the retrieved set of engine-off-natural-vacuum test results from the plurality of other vehicles. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
-
-
13. A method comprising:
-
conducting a test for undesired evaporative emissions at a key-off event stemming from a fuel system and an evaporative emissions system of a vehicle beginning with a positive pressure phase portion of the test first, and then conducting a vacuum phase portion if the vehicle does not pass the test during the positive pressure phase portion, in response to an indication that the vehicle can pass the test during the positive pressure phase portion; and conducting the vacuum phase portion of the test first and not conducting the positive pressure phase portion in response to an indication that the vehicle can pass the test during the vacuum phase portion of the test, wherein the indication that the vehicle can pass the test during the positive pressure phase portion and the indication that the vehicle can pass the test during the vacuum phase portion of the test are based on a set of test results retrieved wirelessly via a controller of the vehicle from a plurality of other vehicles tested after similar drive cycle conditions as the vehicle. - View Dependent Claims (14, 15, 16, 17)
-
-
18. A system for a vehicle, comprising:
-
a fuel system including a fuel tank fluidically coupled to an evaporative emissions system; an engine system including an engine configured to propel the vehicle by combusting air and fuel; a canister vent valve positioned in a vent line of the evaporative emissions system; a wireless communication device configured to send and receive wireless signals; and a controller storing instructions in non-transitory memory that, when executed, cause the controller to; during a current drive cycle, send one or more wireless signals to a plurality of other vehicles that have recently conducted a first test for undesired evaporative emissions stemming from a fuel system and/or an evaporative emissions system of the plurality of other vehicles; retrieve results of the first test from the plurality of other vehicles; process the retrieved results of the first test from the plurality of other vehicles to indicate whether the plurality of other vehicles are tending to pass or fail the first test during a pressure phase portion of the first test or a vacuum phase portion of the first test; set an initial vent time for conducting a second test for undesired evaporative emissions stemming from the fuel system and/or the evaporative emissions system of the vehicle as a function of whether the plurality of other vehicles are tending to pass the first test during the pressure phase portion or the vacuum phase portion of the first test; and responsive to the first test from the plurality of other vehicles tending to fail during the pressure phase portion of the first test, commencing the second test for undesired evaporative emissions with a vacuum phase portion of the second test, where the vacuum phase portion of the second test is commenced after the initial vent time for conducting the second test has elapsed. - View Dependent Claims (19)
-
Specification