Study of Durability Test System for Powertrain Control Module (PCM)
Dec 29, 2022 View: 383
The Powertrain Control Module (PCM) is the control nerve center of a vehicle, which directly affects the power and fuel economy of the vehicle and exhaust emissions. With the development of the automotive electronics industry, PCM has become a standard configuration of automobiles. Since PCM systems are very complex and work in extremely harsh environments, their reliability is critical. Therefore, PCM durability testing is important for developing PCMs for automotive engines.
In the 1980s, several internationally renowned PCM module manufacturing companies, such as Bosch, Siemens, Delphi, and Visteon, researched PCM durability testing technology for their products and developed corresponding equipment. As such equipment still follows the design system of more than 20 years ago, it can no longer adapt to the development of the rapidly changing automotive EFI engine technology, the overall technical platform is backward, and there are some impossible defects, such as not being compatible with PCM modules of different manufacturers, not being able to set the automatic cycle strategy, not being able to configure the analog signal type and parameters on site, etc.
This paper introduces the overall design idea and test specification of the automotive PCM durability test system, focuses on the design principle of key subsystems, and verifies the reliability and universality of the system through the longevity test of several PCM modules by the prototype.
PCM Working Principle
The automotive engine control module (PCM) is the core component of the automotive control system, which mainly consists of five parts: input circuit, analog signal, digital signal converter, microcomputer, and output circuit. Its role is to receive various sensor signals through the microcomputer's calculation and processing, send commands to the actuators, turn on the ground wire of each actuator so that they are energized and work to accurately control the fuel supply, ignition advance angle, and idle airflow.
The design idea of the PCM durability test system
Based on the control technology of the EFI engine, this paper designs a general open PCM durability test system using multi-layer CAN bus communication technology, virtual instrument technology, and an embedded computer system. It mainly consists of industrial control computer (IPC), signal generation subsystem, analog load subsystem, load monitoring subsystem, high-power programmable power supply, environmental experiment box, field bus communication subsystem, application software, and database management system.
The test principle of this test system: taking PCM as the test object, the industrial control computer sends setting instructions according to the different test types and test items, controls the environment variables and high-power DC power supply, quickly switches the car sensor signal, and analog load connection, and sends reading instructions to the load monitoring system in time to monitor the PCM operation status online.
PCM durability test specification
The durability test specification is the basis of the PCM durability test and is related to the overall quality of PCM. To improve the reliability and durability of PCM during normal operation, it is necessary to establish a set of test specifications that can stimulate PCM failure to the maximum extent. Principles for establishing durability test specifications for this system.
(1) Fully consider the multiple stress parameters that cause PCM failure.
(2) Ensure sufficient test time to verify that the PCM module has sufficient reliability over its expected lifetime.
Because the PCM is a mission-critical subsystem that ensures vehicle performance and enables a safe driving experience, its reliability and durability are critical. That's why best-in-class automotive customers trust us to customize PCM solutions for their end-use needs.