LV 124 — 12 V Vehicle Components Electrical and Environmental Test Specification

What Is LV 124?

LV 124 is a test specification developed by German automotive manufacturers that comprehensively defines electrical, mechanical, climatic and life tests for 12 V components in vehicles up to 3.5 tonnes.

Purpose of LV 124

The aim is to verify reliable operation of the component under voltage fluctuations in the vehicle 12 V network, environmental conditions and life requirements.

Which Products Is LV 124 Applied To?

12 V electronic control units
Sensors and actuators
Lighting and display modules
Comfort and body electronics

In Which Sectors Is LV 124 Used?

ElectronicsElectricalAutomotiveTelecommunicationsDefence

Standards Related to LV 124

LV 124
ISO 16750 series
ISO 7637electrical transients conducted in vehicles test
VW 80000 (equivalent)

LV 124 Conditions

Electrical tests: Prolonged over/under voltage, voltage drop, jump, polarity reversal, short circuit
Climatic experiments: Temperature cycling, humidity, thermal shock, salt fog
Mechanical tests: Vibration and mechanical shock
Lifespan experiments: Continuous operation and accelerated life tests

Equipment for LV 124

Programmable DC power supply and voltage profile generator
climate cabins
Shaking and shock test setup
Multi-channel data recording and monitoring function

Sample Requirements for LV 124

The number of samples is defined in the specification and varies depending on the experimental group.
Function monitoring points and acceptance criteria should be determined
Wiring harness and connector layout must represent actual vehicle
Software version must be registered

Duration of LV 124

The full LV 124 program is comprehensive; It may take weeks to months with lifespan experiments.

LV 124 Procedure

1The test matrix and sample allocation in the specification are planned.
2Electrical experiments are performed with voltage profiles.
3Climatic experiments are carried out in cabins.
4Mechanical experiments are carried out in shaker and shock systems.
5Function and parameter checks are performed after each experiment.
6Results are reported according to the experiment matrix.

LV 124 Acceptance Criteria

Acceptance criteria are defined individually for each test in LV 124 and are generally evaluated according to function classes (Classes A–C).

Evaluation of Results

The entire experimental matrix is evaluated together; Passing a single test does not mean compliance. Sample allocation and experimental order affect the outcome.

LV 124 Report

Applied specification and revision
Experimental matrix and sample allocation
Parameters and results for each experiment
Function class considerations
Software version and configuration

Accreditation

EUROLAB holds internationally recognised accreditation obtained from accreditation bodies party to the IAF and ILAC multilateral recognition arrangements, under ISO/IEC 17025 for laboratory testing, ISO/IEC 17020 for inspection and surveillance, and ISO/IEC 17021-1 and ISO/IEC 17065 for system and product certification. This chain ensures the reports and certificates issued are accepted worldwide.

Whether this test can be offered within accredited scope depends on your product and the standard applied; since accreditation is method-based, the scope is confirmed in writing at the quotation stage.

Scope and authorisations

Related Regulations

Automotive OEM specifications

EMC / EMI Testleri — What Does This Testing Field Cover?

The section below describes the field that the LV 124 test belongs to; the conditions and acceptance criteria of this particular test are given in the sections above. The scope specific to your product is confirmed in writing at the quotation stage.

EMC testing answers a question with two sides: does the device emit an unacceptable level of electromagnetic interference into its surroundings (emission), and does it withstand the interference coming from them (immunity)? The two sides are measured with separate tests and separate set-ups, and both are required.

The field exists because of a simple physical fact: every conductor carrying current behaves like an antenna. A switched-mode power supply, a motor drive or the clock signal of a microcontroller radiates radio frequency energy even though it was never designed to. The same conductor also works in reverse: an external field induces a voltage across it. In an environment crowded with devices, this mutual effect means devices disturbing one another.

On the emission side, conducted and radiated emission are measured separately. Conducted emission is the interference the device imposes on its mains and communication cables and dominates at lower frequencies. Radiated emission is the field the device releases into the air and comes to the fore at higher frequencies. The two are measured in different set-ups, and the limits vary by product group.

On the immunity side, real-world sources of interference are simulated: electrostatic discharge (human touch), radiated radio frequency fields (a nearby transmitter), electrical fast transients (switching), surges (lightning and mains events), conducted radio frequency, power-frequency magnetic fields, voltage dips and short interruptions.

The standard to be applied depends on WHERE the product is used, and that choice determines the entire outcome. Residential and industrial environments carry different sets of limits; in vehicles the UNECE R10 regime applies rather than CE; for medical devices IEC 60601-1-2 brings additional requirements; and for products containing a radio, radio legislation comes into play and harmonised ETSI standards are used.

In immunity testing the acceptance criterion is a PERFORMANCE CRITERION class, not a binary pass/fail. A device continuing to function without interruption during the test, being temporarily affected and recovering by itself, or recovering only through user intervention are different classes. Which class is acceptable is defined in the product standard; the tolerance for a device carrying a safety function differs from that of a consumer device.

The most common shortcoming of an EMC file is that it covers only one side. A file carrying an emission report alone is not complete in terms of the EMC directive. The second common gap is a test set-up that does not represent actual use: if the device is measured on a bare bench with cables different from its real ones, the result does not carry over to the field.

Method groups in this field

Conducted emission
Interference imposed on the cable through mains and communication ports, measured via an artificial mains network (LISN).
Radiated emission
The field released into the air by the device, measured at a defined distance in an anechoic or semi-anechoic chamber.
Harmonics and flicker
The harmonic content of the current drawn from the mains and voltage fluctuation; the side that affects mains quality.
Electrostatic discharge
Contact and air discharge together with indirect discharge; the most frequently applied immunity test.
Radiated and conducted RF immunity
The device is exposed to a defined field strength and to an RF signal injected into the cable.
Mains-borne events
Electrical fast transients, surges, voltage dips and short interruptions.

Commonly confused in this field

An emission report alone does not complete an EMC file; immunity must be demonstrated as well.
An FCC report is not accepted in a CE file; the limits, measurement distances and set-ups are different.
The EMC Directive does not apply to vehicles; the UNECE R10 regime does. Specifications requiring both together should be reviewed.
The warning that a Class A device may cause interference in a residential environment is mandatory in the manual; market surveillance checks that this warning is present.
The test set-up is part of the report. If cable type, length or routing changes, the result changes; measurement must be made in the series-production configuration.
CISPR 22 and CISPR 13 have been withdrawn; their current counterparts are CISPR 32 and CISPR 35.

Which decisions these results support

CE declaration under the EMC Directive
The EMC part of radio equipment conformity
A UNECE R10 file for a vehicle component
Resolving field interference complaints and correcting the design
Assessing the EMC impact of a board or wiring-harness change

Related Tests

Frequently Asked Questions About LV 124

Is LV 124 a standard or specification?

It is not an international standard, but a test specification developed by automotive manufacturers. Therefore, it should be clarified in advance which revision and which OEM supplement will be applied.