Need For Automotive Diagnostics

Automotive diagnostics also referred to as UDS(Unified Diagnostic Services) is also an ISO standard named under ISO 14229–1. Now to illustrate the need for UDS, see below.

A common machine language or in this case a communication protocol was required to talk to different and ever-growing Electronic control unit (ECUs) in any vehicle and across the globe. Hence an international standard was created.

In simple terms, imagine a fault in the vehicle e.g., with the engine, so the module related to the engine, engine control module (ECM) would set a flag in it, saves a lot of data about the issue, and would be communicated to the IPC (instrument panel cluster, or the speedometer unit underneath the steering wheel). Once, the IPC receives the issue, it enables a service Engine LED.

Now consider, when this happens, and the vehicle is at the service center, how would the technician understand the issue?

The technician would have a device to query the issues which are ISO-14229 compliant and can read the saved data pointing to the issue to take any further steps (Upgrading the SW, Replacing the ECU, etc.).

Seems simple? Very well then. Now that we know how automotive diagnostics is used in one of the mentioned scenarios above, we can start learning more in detail to know other advantages.

PRE-REQUISITE

Before moving forward, the article assumes that you are aware of the CAN protocol.