Faster and some-more efficient: new processes for on-board diagnostics system

On-board diagnostics (OBD) monitors a functionality of exhaust-related components over a life of a vehicle. To do this, exam routines are implemented in all applicable control units of a car and run while a car is in motion. If an electronic control section (ECU) earnings improbable feedback, a analogous formula is stored in a OBD blunder memory of a ECU—for instance if AFR sensor no longer rightly detects a oxygen calm in a empty gas and a engine control section afterwards changes a explosion parameters. At a same time, a yellow malfunction indicator light in a cockpit flashes.

OBD originated in a United States: It was introduced in California in 1988 and around a US in 1994. Two years later, stricter emissions boundary led to a some-more absolute OBD II complement still in use today, that monitors emissions some-more precisely, includes other components in a check, and offers some-more minute evidence options for workshops. OBD became imperative in Europe in 2001, though with partly opposite mandate than in a US. In particular, emissions boundary and dimensions cycles differ significantly. Other regions such as China followed fit in successive years.

OBD was initial introduced in California in 1988 and around a US in 1994. It has also been imperative in Europe given 2001. China and other regions followed fit in successive years.

At Porsche, a checking of a OBD complement for a new car indication is divided into 3 steps: firstly, peculiarity declaration tests while a car is still being calibrated; secondly, form capitulation tests in a supposed OBD demo proviso as a mandatory exigency for approval; and thirdly, after a start of array production, a extensive hearing of all intensity OBD blunder memory entries on vehicles from stream production. Throughout all phases, Porsche Engineering and Porsche AG pull on a partnership that has grown over many years. “As a rule, we start checking a OBD calibration about 6 months before a start of production. If a tests exhibit any abnormalities, we investigate a causes and advise probable visual measures,” says Dr. Matthias Bach, Senior Manager Engine Calibration and Mechanics during Porsche Engineering, underneath whose reach on-board diagnostics falls.

Coordination with acceptance authorities

In a OBD demo proviso that follows, it is demonstrated that a vehicle’s OBD complement complies with authorised requirements. To this end, Porsche AG coordinates exam array with a acceptance authorities in a individual regions around a world, that a experts in Porsche Engineering’s contrast dialect afterwards work their approach through. “We cover 145 markets, 10 of that have particular acceptance procedures,” says Thomas Rauner, Director of a Homologation Powertrain Department during Porsche AG. The opposite emissions laws, exam cycles, and OBD mandate make growth and contrast intensely complex. A new instance is China, where a China 6b standard, that will be adoped in 2023, stipulates perfectionist OBD exam conditions. “Unlike in a rest of a world, a certain exam news will afterwards no longer be sufficient in China to plead a new car model. Rather, a OBD exam contingency be carried out on site and underneath a organisation of a authorities,” explains Dr. Sebastian Rüger, who is obliged for OBD acceptance during Porsche AG, among other roles.

3,500 probable blunder codes from a framework and powertrain areas exist in hybrid vehicles.

As Porsche China’s disdainful vital partner, Porsche Engineering supports on-site acceptance by providing technical services such as conducting a exam series. Porsche AG is obliged for coordinating the exam formula with a particular acceptance authorities. “Thanks to tighten mild relations and continual sell of information between a colleagues of Porsche Engineering in China and Germany as good as Porsche AG, we are means to exercise a capitulation of a car indication on a parsimonious timeframe in a process,” says Rauner.

For a OBD form capitulation tests of a new car model, Porsche Engineering carries out adult to 80 exam runs on a dynamometer, recreating several emissions-relevant events such as a shop-worn lambda sensor line. For example, a engineers implement specifically prepared components in a car or copy predefined blunder cases. To copy a wear and rip of many years, they also use components such as catalytic converters that have been subjected to an fake aging process.

In serve to authorised requirements, a ever-increasing series of electronic systems in a car is also heading to larger OBD complexity. OBD not only monitors particular components, though also checks whole organic sequences, including intensity cross-influences from other car systems. 

“We cover 145 markets, 10 of that have particular capitulation procedures.”
Thomas Rauner, Director of a Homologation Powertrain Department during Porsche AG

This also includes control units that could indirectly change emissions in a eventuality of a defect, for instance for Adaptive Cruise Control (ACC), Porsche Stability Management (PSM), and a Remote Park Assistant, that automatically parks a vehicle. “As partial of a OBD corroboration tests compulsory by a authorities, a Product Vehicle Evaluation, we have to infer that a emissions-neutral remuneration magnitude is carried out correctly—in other words, that it no longer has any change on a vehicle’s emissions behavior,” says Rüger. “Experts impute to this as an Emissions Neutral Default Action, or ENDA for short.” The ensuing contrast bid is together high: “In complicated hybrid vehicles, we have adult to 14 ECUs from a powertrain and framework areas with around 3,500 probable blunder codes,” says Bach.

Simulation of errors

These have to be accurate within a duration of adult to 6 months after a car goes into production. To save time and costs, Porsche Engineering relies roughly exclusively on a make-believe of faults. “Instead of installing and stealing poor components for exam dais examinations or highway tests during good expense, we cgange a particular sensor signals or messages in a vehicle’s electronic information system,” explains Bach. This requires an in-depth bargain of a member and a duty in a altogether system, which Porsche Engineering, as an OBD use provider from a really beginning, has gained in large growth projects. “Our strength is a imagination in a areas of finish vehicles and testing. On this basis, we have grown a possess contrast and make-believe tools, that can be used to imitate around 95 percent of a defects in a OBD system,” explains Bach.


Investigation of emissions-related events: for a form capitulation tests of a new car model, Porsche Engineering carries out adult to 80 exam runs on a dynamometer.

For example, a duty of a stifle valve actuator is unnatural outwardly during engine operation, so a stifle valve commissioned in a car can be tested separately. In sequence to arrangement a preferred blunder memory entries for a injectors, specifically grown program is used to change a injection apportion of a injectors within a really excellent range. “When it comes to simulating networking faults in a wiring architecture, we are always adult to date interjection to a clever team-work with colleagues in growth and can therefore benefaction a suitable exam procession as shortly as new evidence functions are introduced,” says Bach.

“Our strength is a imagination in a areas of finish vehicles and testing.”
Dr. Matthias Bach, Senior Manager Engine Calibration and Mechanics during Porsche Engineering

The outcome is an intensely quick and fit OBD process. It is foreseeable that a ensuing advantages will turn even some-more critical in a future, as stricter emissions standards, such as a Euro 7 customary now underneath discussion, serve revoke a slight empty gas boundary worldwide. Thus a turn of OBD growth continues to turn: new systems and functions capacitate reduce emissions values, that are afterwards tested again around a softened OBD. In addition, there are evidence tasks outset from a use of fake fuels famous as e-fuels. “It can be insincere that electric cars will also have to pass an OBD exam in a future,” says Bach with a perspective to a future. “It would afterwards be about a condition of a powertrain and battery rather than nitrogen oxide or particulate emissions.”

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Text: Richard Backhaus

Text initial published in a Magazine Porsche Engineering, emanate 2/2021.