Commission Directive 2005/78/EC (repealed)Dangos y teitl llawn

Appendix 1 ON-BOARD DIAGNOSTIC (OBD) SYSTEM APPROVAL TESTS

1. INTRODUCTION U.K.

This Appendix describes the procedure for checking the function of the on board diagnostic (OBD) system installed on the engine by failure simulation of relevant emission-related systems in the engine management or emission control system. It also sets procedures for determining the durability of OBD systems.

1.1. Deteriorated components/systems U.K.

In order to demonstrate the efficient monitoring of an emission control system or component, the failure of which may result in tailpipe emissions exceeding the appropriate OBD threshold limits, the manufacturer must make available the deteriorated components and/or electrical devices which would be used to simulate failures.

Such deteriorated components or devices must not cause emissions to exceed the OBD threshold limits referred to in the table in Article 4(3) of this Directive by more than 20 %.

In the case of type-approval of an OBD system according to Article 4(1) of this Directive, the emissions shall be measured over the ESC test cycle (see Appendix 1 to Annex III to Directive 2005/55/EC). In the case of type-approval of an OBD system according to Article 4(2) of this Directive, the emissions shall be measured over the ETC test cycle (see Appendix 2 to Annex III to Directive 2005/55/EC).

1.1.1. If it is determined that the installation of a deteriorated component or device on an engine means that a comparison with the OBD threshold limits is not possible (e.g. because the statistical conditions for validating the ETC test cycle are not met), the failure of that component or device may be considered as qualified upon the agreement of the type-approval authority based on technical argumentation provided by the manufacturer. U.K.

1.1.2. In the case that the installation of a deteriorated component or device on an engine means that the full load curve (as determined with a correctly operating engine) cannot (even partially) be attained during the test, the deteriorated component or device is considered as qualified upon the agreement of the type-approval authority based on technical argumentation provided by the manufacturer. U.K.

1.1.3. The use of deteriorated components or devices that cause engine emissions to exceed the OBD threshold limits referred to in the table in Article 4(3) of this Directive by no more than 20 % may not be required in some very specific cases (for example, if a limp home strategy is activated, if the engine cannot run any test, or in case of EGR sticking valves, etc). This exception shall be documented by the manufacturer. It is subject to the agreement of the technical service. U.K.

1.2. Test principle U.K.

When the engine is tested with the deteriorated component or device fitted, the OBD system is approved if the MI is activated. The OBD system is also approved if the MI is activated below the OBD threshold limits.

The use of deteriorated components or devices that cause the engine emissions to exceed the OBD threshold limits referred to in the table in Article 4(3) of this Directive by no more than 20 % are not required in the specific case of the failure modes described in sections 6.3.1.6 and 6.3.1.7 of this Appendix and also with respect to monitoring for major functional failure.

1.2.1. The use of deteriorated components or devices that cause engine emissions to exceed the OBD threshold limits referred to in the table in Article 4(3) of this Directive by no more than 20 % may not be required in some very specific cases (for example, if a limp home strategy is activated, if the engine cannot run any test, or in case of EGR sticking valves, etc). This exception shall be documented by the manufacturer. It is subject to the agreement of the technical service. U.K.

2. DESCRIPTION OF TEST U.K.

2.1. The testing of OBD systems consists of the following phases: U.K.

• simulating the malfunction of a component of the engine management or emission control system as described in section 1.1 of this Appendix

• preconditioning of the OBD system with a simulated malfunction over the preconditioning cycle specified in section 6.2

• operating the engine with a simulated malfunction over the OBD test cycle referred to in section 6.1

• determining whether the OBD system reacts to the simulated malfunction and indicates malfunction in an appropriate manner.

2.1.1. Should the performance (e.g. power curve) of the engine be affected by the malfunction, the OBD test-cycle remains the shortened version of the ESC test-cycle used for the assessing the exhaust emissions of the engine without that malfunction. U.K.

2.2. Alternatively, at the request of the manufacturer, malfunction of one or more components may be electronically simulated according to the requirements of section 6. U.K.

2.3. Manufacturers may request that monitoring take place outside the OBD test cycle referred to in section 6.1 if it can be demonstrated to the authority that monitoring during conditions encountered during this OBD test cycle would impose restrictive monitoring conditions when the vehicle is used in service. U.K.

3. TEST ENGINE AND FUEL U.K.

3.1. Engine U.K.

The test engine shall comply with the specifications laid down in Appendix 1 of Annex II to Directive 2005/55/EC.

3.2. Fuel U.K.

The appropriate reference fuel as described in Annex IV to Directive 2005/55/EC must be used for testing.

4. TEST CONDITIONS U.K.

The test conditions must satisfy the requirements of the emission test described in the present directive.

5. TEST EQUIPMENT U.K.

The engine dynamometer must meet the requirements of Annex III to Directive 2005/55/EC.

6. OBD TEST CYCLE U.K.

6.1. The OBD test cycle is a single shortened ESC test cycle. The individual modes shall be performed in the same order as the ESC test cycle, as defined in section 2.7.1 of Appendix 1 to Annex III to Directive 2005/55/EC. U.K.

The engine must be operated for a maximum of 60 seconds in each mode, completing engine speed and load changes in the first 20 seconds. The specified speed shall be held to within ±50 rpm and the specified torque shall be held to within ±2 % of the maximum torque at each speed.

Exhaust emissions are not required to be measured during the OBD test cycle.

6.2. Preconditioning cycle U.K.

6.2.1. After introduction of one of the failure modes given in section 6.3, the engine and its OBD system shall be preconditioned by performing a preconditioning cycle. U.K.

6.2.2. At the request of the manufacturer and with the agreement of the type-approval authority, an alternative number of a maximum of nine consecutive OBD test cycles may be used. U.K.

6.3. OBD system test U.K.

6.3.1. Diesel engines and vehicles equipped with a diesel engine U.K.

6.3.1.1. After preconditioning according to section 6.2, the test engine is operated over the OBD test cycle described in section 6.1 of this Appendix. The MI must activate before the end of this test under any of the conditions given in 6.3.1.2 to 6.3.1.7. The technical service may substitute those conditions by others in accordance with section 6.3.1.7. For the purposes of type-approval, the total number of failures subject to testing, in the case of different systems or components, must not exceed four. U.K.

If the test is being carried out to type-approve an OBD-engine family consisting of engines that do not belong to the same engine family, the type approval authority will increase the number of failures subject to testing up to a maximum of four times the number of engine families present in the OBD-engine family. The type-approval authority may decide to curtail the test at any time before this maximum number of failure tests has been reached.

6.3.1.2. Where fitted in a separate housing that may or may not be part of a deNO_x system or diesel particulate filter, replacement of any catalyst with a deteriorated or defective catalyst or electronic simulation of such a failure. U.K.

6.3.1.3. Where fitted, replacement of a deNO_x system (including any sensors that are an integral part of the system) with a deteriorated or defective deNO_x system or electronic simulation of a deteriorated or defective deNO_x system that results in emissions exceeding the OBD NO_x threshold limit referred to in the table given in Article 4(3) of this Directive. U.K.

In the case that the engine is being type-approved according to Article 4(1) of this Directive in relation to monitoring for major functional failure, the test of the deNO_x system shall determine that the MI illuminates under any of the following conditions:

• complete removal of the system or replacement of the system by a bogus system

• lack of any required reagent for a deNO_x system

• any electrical failure of a component (e.g. sensors and actuators, dosing control unit) of a deNO_x system, including, when applicable, the reagent heating system

• failure of a reagent dosing system (e.g. missing air supply, clogged nozzle, dosing pump failure) of a deNO_x system

• major breakdown of the system.

6.3.1.4. Where fitted, total removal of the particulate filter or replacement of the particulate filter with a defective particulate filter that results in emissions exceeding the OBD particulate threshold limit given in the table in Article 4(3) of this Directive. U.K.

In the case that the engine is being type-approved according to Article 4(1) of this Directive in relation to monitoring for major functional failure, the test of the particulate filter shall determine that the MI illuminates under any of the following conditions:

• complete removal of the particulate filter or replacement of the system by a bogus system

• major melting of the particulate filter substrate

• major cracking of the particulate filter substrate

• any electrical failure of a component (e.g. sensors and actuators, dosing control unit) of a particulate filter

• failure, when applicable, of the reagent dosing system (e.g. clogged nozzle, dosing pump failure) of a particulate filter

• a clogged particulate filter resulting in a differential pressure out of the range declared by the manufacturer.

6.3.1.5. Where fitted, replacement of a combined deNO_x-particulate filter system (including any sensors that are an integral part of the device) with a deteriorated or defective system or electronic simulation of a deteriorated or defective system that results in emissions exceeding the OBD NO_x and particulate threshold limits given in the table in Article 4(3) of this Directive. U.K.

In the case that the engine is being type-approved according to Article 4(1) of this Directive in relation to monitoring for major functional failure, the test of the combined deNO_x-particulate filter system shall determine that the MI illuminates under any of the following conditions:

• complete removal of the system or replacement of the system by a bogus system

• lack of any required reagent for a combined deNO_x-particulate filter system

• any electrical failure of a component (e.g. sensors and actuators, dosing control unit) of a combined deNO_x-particulate filter system, including, when applicable, the reagent heating system

• failure of a reagent dosing system (e.g. missing air supply, clogged nozzle, dosing pump failure) of a combined deNO_x-particulate filter system

• major breakdown of a NO_x trap system

• major melting of the particulate filter substrate

• major cracking of the particulate filter substrate

• a clogged particulate filter resulting in a differential pressure out of the range declared by the manufacturer.

6.3.1.6. Disconnection of any fuelling system electronic fuel quantity and timing actuator that results in emissions exceeding any of the OBD thresholds referred to in the table given in Article 4(3) of this Directive. U.K.

6.3.1.7. Disconnection of any other emission-related engine component connected to a computer that results in emissions exceeding any of the thresholds referred to in the table given in Article 4(3) of this Directive. U.K.

6.3.1.8. In demonstrating compliance with the requirements of 6.3.1.6 and 6.3.1.7 and with the agreement of the approval authority, the manufacturer may take appropriate steps to demonstrate that the OBD system will indicate a fault when disconnection occurs. U.K.