Transcript European Heavy-Duty OBD Update GRPE, Geneva 29-30 May 2001 Dr Paul Greening European Commission Political mandate • Directive 1999/96/EC requires that by end 2000, Commission must propose: –

European Heavy-Duty OBD
Update
GRPE, Geneva
29-30 May 2001
Dr Paul Greening
European Commission
Political mandate
• Directive 1999/96/EC requires that by end
2000, Commission must propose:
– heavy-duty vehicle durability;
– heavy-duty vehicle in-use conformity testing;
– heavy-duty vehicle OBD.
• and deal with issues regarding measurement
of low PM mass for Euro 4.
OBD scope - diesel engines
• OBD monitoring of the engine plus any
downstream emission control system:
– applicable to new diesel engines from 1st
October 2005 (Euro 4).
OBD scope - diesel vehicles
• OBD monitoring of the engine plus any
downstream emission control system:
– diagnostic interface between the ECU and other
vehicle electronic systems that provide an input
to or receive an output from the ECU;
– applicable to new vehicles with diesel engines
from 1st October 2008 (Euro 5).
European Steady Cycle (ESC)
Load
100
Mode
1
2
3
4
5
6
7
8
9
10
11
12
13
75
50
25
0
15%
idle
Speed
idle
A
B
B
A
A
A
B
B
C
C
C
C
Load
100
50
75
50
75
25
100
25
100
25
75
50
50
8%
9%
8%
5%
10%
5%
5%
10%
5%
5%
10%
5%
A
75
B
Engine speed
C
100
OBD demonstration test
• OBD monitoring likely to be evaluated over
the ESC test cycle. Why ?
– ESC provides sufficient steady-state driving (4
min. idle mode, 2 min. per mode) to enable
system monitoring to be demonstrated;
– ESC modes may be too long;
– ESC also has transient elements between modes
(max. 20 sec. per mode change).
European Transient Cycle (ETC)
110
95
n/s
T/Tmax(n)
90
90
85
80
80
70
75
60
70
50
65
40
60
30
55
20
50
10
45
0
40
-10
35
-20
30
-30
25
0
200
400
600
800
1000
Time in s
1200
1400
1600
1800
Normalized Engine Speed (n/s) in %
Normalized Engine Torque (T/Tmax(n)) in %
100
OBD demonstration test
• What about the ETC test ?
– Supposed to represent ‘real’ European HDV
driving;
– ETC does offer some steady-state driving
periods but the variation in engine load is
probably too great;
– Presently reviewing OBD monitoring capability
over the ETC.
Sensors
• NOx sensors:
– Siemens-NGK electro-chemical sensor is
available for test purposes;
– Light duty applications this year (0-500ppm
range); NOx sensor for HDV applications mid2003 (0-1500ppm range);
– Other manufacturer sensors at similar stage of
development;
– Cross-sensitivity to NH3.
Sensors
• NH3 sensors:
– Necessary for SCR applications to monitor NH3
slip;
– Few automotive developments so still far from
production.
• Particulate sensors:
– Pressure drop over trap;
– Sooting, ultrasound, laser-induced
incandescence sensors under development.
OBD monitoring functionality
• Today, big problem is setting appropriate
OBD threshold limits for monitoring
deNOx and DPF;
– sensor developments for application in 2005
(Euro 4) uncertain;
– Durability needs to be defined;
• For 2005 propose to monitor deNOx, DPF
or combined deNOx-DPF only for major
functional failure.
OBD monitoring functionality
• What is major functional failure of deNOx
or DPF:
–
–
–
–
–
removal or replacement of systems;
lack of reagent for SCR;
electrical failure of SCR actuators;
breakdown of NOx trap;
breakdown of DF:
• major melting of trap substrate;
• clogged filter resulting in P out of range.
Failure analysis
• For type-approval, the manufacturer will
have to declare the parameters used as a
basis for major functional failure:
– provide an analysis of potential failures in the
emission control system;
– detail effect of failures on emissions;
– information remains confidential;
– Directive 98/12 requires this for ABS.
OBD monitoring thresholds
• OBD ‘threshold limits’ will be applicable
for diesel engines without after-treatment
dealing with either the emission of NOx or
particulate;
– Major functional failure plus NOx and
particulate threshold limits for 2005;
– Only thresholds for 2008;
– No need for diesel HC and CO thresholds.
OBD monitoring thresholds
• Threshold levels will be defined to:
– be realistic for 2005;
– be progressive for 2008, to push sensor
development;
– take account of the political process;
• 2008 ‘threshold only’ concept should be
reviewed by end of 2004 to assess progress
in sensor development.
General requirements
• Similar in concept to light-duty vehicle
OBD with defined minimum monitoring:
–
–
–
–
reduction in efficiency of deNOx;
functionality & integrity of DPF;
combined deNOx-DPF systems;
fuel injection equipment for functionality and
continuity;
– [lack of cylinder combustion];
– other emission-related components.
General requirements
• Activation and de-activation of malfunction
indicator:
– will include for lack of SCR reagent;
– can be de-activated after 40 engine warm-up
cycles or 100 engine running hours, whichever
first;
– If MI activated due to lack of reagent, MI may
be switched back to previous state of activation
after [urea] re-fill.
General requirements
• Provisions for unrestricted access for repair
etc;
• Provisions for deficiencies included, similar
to light-duty EOBD:
– Two deficiencies;
– Allowed for two years (three years);
– No deficiency if:
• complete lack of diagnostic monitor;
• OBD thresholds are exceeded.
General requirements
• Anti-tampering, like passenger cars, to
cover, e.g:
– manipulation of hardware, software, calibration
parameters;
– data modification;
– addition of new devices that could affect OBD
monitoring;
– exemptions from requirements possible based
on certain criteria.
Temporary disablement
• If fuel level below 20% capacity;
• During the permitted functioning of an
‘auxiliary control device’ (2001/27/EC);
• During exceptional control strategies such
as limp-home or security/safety strategies;
• When power-take off units are active;
• During periodic regeneration of DPF or
deNOx.
Engine family
• Take on-board the provisions of ISO 16185
to define:
– general engine family concept;
– OBD engine family concept.
Small OBD families
• Less than 500 units per year world-wide:
– OBD required but monitoring of engine and
after-treatment only with respect to major
functional failure;
• Less than 50 units per year world-wide:
– OBD required but monitoring of engine and
after-treatment only with respect to circuit
continuity.
Enforcement
• Running hours since activation of
malfunction indicator;
• Reviewing the possible use of more than 1
freeze-frame as FI-FO buffer for an onboard fault history coupled with running
hours/distance.
Access to diagnostic data
• Similar in concept to light-duty vehicle
OBD;
– through standard connector;
– common connector for light-duty vehicles and
heavy-duty vehicles?
• Provisions to allow the use of an on-board
diagnostic facility (in place of off-board
scan tools) if it offers the same level of
diagnostic access.
HDV OBD - next steps
• Commission proposal is due in June;
• Further proposals will come later:
– gas engine OBD;
– OBD test cycle based on WHDC;
– enhanced running time/fault code storage
procedure as enhanced in-use conformity
procedure;
– replacement parts.