ZEVonUDS

ZEVonUDS is being introduced in order to read out EV-specific measurement data with a scan tool in particular, e.g. battery state-of-health, which is used as a quantitative variable in determining the residual value of an electric vehicle.

In addition, it must be ensured that electric vehicles are operated as energy-efficiently as possible to minimize pollution arising from electrical power generation. Energy losses during the storage of electricity in the vehicles' traction batteries and during the conversion of electrical energy into kinetic energy should be minimized. Faulty operating states are then easily read out from the vehicle by scan tools based on the new ZEVonUDS standard.

Furthermore, the SAE J1979-3 ZEVonUDS standard is used by CARB to record repairs on electric and plug-in hybrid vehicles registered for sale in California. In the U.S., a so-called ZEV warranty has been introduced for electric and hybrid vehicles. This states that in the first three years (equivalent to 50,000 miles), there must be no defects in drive-related parts. For cost-intensive parts that need to be replaced, the period is set at 7 years (equivalent to 70,000 miles). In addition, a minimum residual capacity of 80% applies to the battery after 8 years (corresponding to 100,000 miles). If a threshold for warranty claims is exceeded, vehicle manufacturers are required to submit quarterly status reports to CARB. These include the number and percentage of warranty claims.

ZEVonUDS describes vehicle access also for OBD diagnostics via DoIP (ISO 13400-2 Diagnostics over IP) for the first time. Thus, ZEVonUDS allows access via CAN (ISO 14229-2) as well as via DoIP (ISO 13400-2). However, a vehicle may only support one of the two types of access at a time.

ZEVonUDS is a subset of OBDonUDS diagnostics. This is also based on the use of UDS (ISO 14229, Unified Diagnostic Services). Unlike the OBDonUDS standard, the ZEVonUDS standard does not include any functions for monitoring exhaust gas behavior. The latter is limited to reading out current diagnostic data and vehicle information, reading out and deleting fault memory entries, and controlling routines.

New challenges arise for both ECU development and diagnostic testers, especially for ZEV start-ups. In the past, these did not have to support On-Board Diagnostics - but now have to implement ZEVonUDS in their ECUs by MY 2026. This requires a fundamental change in the ECU software.

In addition, appropriate specification tools are needed to precisely specify the ZEVonUDS scope per ECU. In particular, future diagnostic variants for different markets must be taken into account in the specification. Further development of diagnostic testers (scan tools) and validation tools is also required. Old tools for J1979-1 OBD II or even modernized tools for J1979-2 OBDonUDS are incompatible and must support vehicle access via DoIP with ZEVonUDS.