Commission Directive 2005/78/EC (repealed)Show full title

6. DIAGNOSTIC SIGNALS U.K.

6.1. Upon determination of the first malfunction of any component or system, ‘freeze-frame’ engine conditions present at the time must be stored in computer memory. Stored engine conditions must include, but are not limited to calculated load value, engine speed, coolant temperature, intake manifold pressure (if available), and the fault code which caused the data to be stored. For freeze-frame storage, the manufacturer must choose the most appropriate set of conditions facilitating effective repairs. U.K.

6.2. Only one frame of data is required. Manufacturers may choose to store additional frames provided that at least the required frame can be read by a generic scan tool meeting the specifications of sections 6.8.3 and 6.8.4. If the fault code causing the conditions to be stored is erased in accordance with section 3.9 of this Annex, the stored engine conditions may also be erased. U.K.

6.3. If available, the following signals in addition to the required freeze-frame information must be made available on demand through the serial port on the standardised data link connector, if the information is available to the on-board computer or can be determined using information available to the on-board computer: diagnostic trouble codes, engine coolant temperature, injection timing, intake air temperature, manifold air pressure, air flow rate, engine speed, pedal position sensor output value, calculated load value, vehicle speed and fuel pressure. U.K.

The signals must be provided in standard units based on the specifications given in section 6.8. Actual signals must be clearly identified separately from default value or limp-home signals.

6.4. For all emission control systems for which specific on-board evaluation tests are conducted, separate status codes, or readiness codes, must be stored in computer memory to identify correctly functioning emission control systems and those emission control systems which require further vehicle operation to complete a proper diagnostic evaluation. A readiness code need not be stored for those monitors that can be considered continuously operating monitors. Readiness codes should never be set to ‘not ready’ status upon ‘key-on’ or ‘key-off’. The intentional setting of readiness codes to ‘not ready’ status via service procedures must apply to all such codes, rather than applying to individual codes. U.K.

6.5. The OBD requirements to which the vehicle is certified (i.e. stage 1 OBD or stage 2 OBD) and the major emission control systems monitored by the OBD system consistent with section 6.8.4 must be available through the serial data port on the standardised data link connector according to the specifications given in section 6.8. U.K.

6.6. The software calibration identification number as declared in Annexes II and VI to Directive 2005/55/EC shall be made available through the serial port of the standardised diagnostic connector. The software calibration identification number shall be provided in a standardised format. U.K.

6.7. The vehicle identification number (VIN) number shall be made available through the serial port of the standardised diagnostic connector. The VIN number shall be provided in a standardised format. U.K.

6.8.

The emission control diagnostic system must provide for standardised or unrestricted access and conform to either ISO 15765 or SAE J1939, as specified in the following sections(1). U.K.

6.8.1. The use of either ISO 15765 or SAE J1939 shall be consistent throughout sections 6.8.2 to 6.8.5. U.K.

6.8.2. The on-board to off-board communications link must conform to ISO 15765-4 or to the similar clauses within the SAE J1939 series of standards. U.K.

6.8.3.

Test equipment and diagnostic tools needed to communicate with OBD systems must meet or exceed the functional specification given in ISO 15031-4 or SAE J1939-73 section 5.2.2.1. U.K.

6.8.3.1. The use of an on-board diagnostic facility such as a dashboard mounted video display device for enabling access to OBD information is permitted but this is in addition to enabling access to OBD information by means of the standard diagnostic connector. U.K.

6.8.4. Diagnostic data, (as specified in this section) and bi-directional control information must be provided using the format and units described in ISO 15031-5 or SAE J1939-73 section 5.2.2.1 and must be available using a diagnostic tool meeting the requirements of ISO 15031-4 or SAE J1939-73 section 5.2.2.1. U.K.

The manufacturer shall provide a national standardisation body with emission-related diagnostic data, e.g. PID’s, OBD monitor Id’s, Test Id’s not specified in ISO 15031-5 but related to this Directive.

6.8.5. When a fault is registered, the manufacturer must identify the fault using the most appropriate fault code consistent with those given in Section 6.3 of ISO 15031-6 relating to emission-related system diagnostic trouble codes. If such identification is not possible, the manufacturer may use diagnostic trouble codes according to Sections 5.3 and 5.6 of ISO 15031-6. The fault codes must be fully accessible by standardised diagnostic equipment complying with the provisions of section 6.8.3 of this Annex. U.K.

The manufacturer shall provide a national standardisation body with emission-related diagnostic data, e.g. PID’s, OBD monitor Id’s, Test Id’s not specified in ISO 15031-5 but related to this Directive.

As an alternative, the manufacturer may identify the fault using the most appropriate fault code consistent with those given in SAE J2012 or in SAE J1939-73.

6.8.6. The connection interface between the vehicle and the diagnostic tester must be standardised and must meet all the requirements of ISO 15031-3 or SAE J1939-13. U.K.

In the case of category N2, N3, M2, and M3 vehicles, as an alternative to the connector location described in the above standards and provided all other requirements of ISO 15031-3 are met, the connector may be located in a suitable position by the side of the driver’s seat, including on the floor of the cabin. In this case the connector should be accessible by a person standing outside the vehicle and not restrict access to the driver’s seat.

The installation position must be subject to agreement of the approval authority such that it is readily accessible by service personnel but protected from accidental damage during normal conditions of use.

(1)

The use of the future ISO single protocol standard developed in the framework of the UN/ECE for a world-wide global technical regulation on heavy-duty OBD will be considered by the Commission in a proposal to replace the use of the SAE J1939 and ISO 15765 series of standards to satisfy the appropriate requirements of section 6 as soon as the ISO single protocol standard has reached the DIS stage.