KWP 2000 is a communication protocol used in the automotive industry for diagnostic purposes. KWP 2000 is an evolution of the older KWP (Keyword Protocol) protocol and has been widely adopted by vehicle manufacturers and service technicians.

What Is KWP 2000 protocol?

KWP 2000 is a communications protocol for OBD II on-board diagnostic systems. Based on OSI application layer and implemented on either K-line (serial) or CAN transport/network layers, it requires special wakeup sequences for initialization.

An ECU interface connects with an external tool or software and transfers data between them, as well as communicating with various car parts like airbags, engines, and transmissions.

KWP 2000 as a Diagnostic protocol

KWP 2000 is an automotive diagnostic protocol used to access real-time vehicle performance data and configure ECU settings. Furthermore, it detects and interprets engine and transmission malfunctions quickly and accurately, helping technicians diagnose problems more accurately than ever.

KWP 2000 differs from OBD2 by being capable of communicating with any vehicle’s ECU, making it more useful across a broader selection of cars. Furthermore, its advanced functionality includes reading and clearing standard diagnostic trouble codes (DTCs). However, its use requires a separate tool in order to connect with ECU.

KWP 2000 is an application layer protocol covering OSI model layers 3 through 7, often implemented on K-line and CAN networks. Compatible with ISO TP 2.0 transport protocols used on CAN, as well as VW TP 2.0 transport protocols for use on K-line, its messages have variable byte lengths so it is essential that an transport protocol with fixed message length be chosen when used with this protocol.

Keyword Protocol 2000 as a communication protocol

Keyword Protocol 2000 is an automotive communication protocol used by mechanics to gain access to an ECU and gather information regarding various issues in a vehicle. Mechanics use it to access fault codes from sensors, actuators and temperature gauges as well as test performance of actuators or activate and deactivate programs in an ECU.

The KWP protocol can be implemented either on K-line physical layer or CAN, used in modern vehicles. It uses half duplex single line with special wakeup sequences required to start communication; variable message length; and requires transport protocol management of packet lengths.

The KWP protocol is similar to UDS in many respects, yet differs in that it offers more diagnostic services and measurements at once than UDS; additionally it has shorter record Local Identifiers than its UDS counterpart; furthermore KWP allows mechanics direct access to vehicle sensor and actuator data without using gateways.

Keyword Protocol 2000 as a standard

WP 2000 is an OBD-II on-board diagnostics communication protocol used to facilitate connections between external diagnostic tools and car’s ECU. As part of OBD-II onboard diagnostics system and DTC diagnostic trouble codes system, it allows external tools to interface with ECU in order to read/write flash dumps; additionally it also supports other functions like reading/writing the software version and hardware version information about an ECU.

The KWP-2000 physical layer employs a 5-baud wakeup sequence which requires the tester to keep both K-line and L-line at high levels during initialization of ECU via 10 bytes address byte, followed by transfer request being transferred out and waiting for response from ECU.

KWP-2000 and UDS are communication protocols designed to allow test equipment to exchange requests with ECUs and receive key measurement values as a response. Their differences lie in their abilities to access certain services such as event triggering and periodic transmission.

Key Features of KWP 2000 protocol

The main features of KWP 2000 include:

  1. Diagnostic Services: Keyword Protocol 2000 defines a set of diagnostic services that allow diagnostic tools (e.g., scan tools) to request information from and send commands to the ECUs in a vehicle. These services include reading and clearing diagnostic trouble codes (DTCs), accessing sensor data, performing tests, and programming ECUs.
  2. Communication Layers: Keyword Protocol 2000 supports different communication layers, with the most common being K-Line (ISO 9141-2) and CAN (Controller Area Network). K-Line is a slower serial communication interface, while CAN provides higher data rates and is more commonly used in modern vehicles.
  3. Keyword Protocol: It utilizes a keyword-based command structure, where diagnostic requests and responses are encoded using keywords and data bytes. This allows for a more compact and standardized way of communicating with different ECUs.
  4. Diagnostic Modes: It defines various diagnostic modes, including the Key Word Protocol Mode (KWP), which is used for standard diagnostics, and the Key Word Protocol Mode 2000 (KWP 2000) for extended diagnostics and reprogramming.
  5. Compatibility: KWP 2000 is designed to be backward compatible with its predecessor, KWP, which helps ensure that diagnostic tools supporting KWP can still communicate with older vehicles using the KWP 2000 protocol.


KWP 2000 is an automotive communication protocol that enables tools to access the electronic control unit (ECU) of a vehicle and retrieve fault codes or retrieve information such as fault diagrams. Furthermore, this protocol also enables activation/deactivation testing on different actuators to identify any issues with certain vehicle models. KWP 2000 supports various sensor types and models, making it suitable for almost all diagnostic scanners or programmers.

Comparative to OBD2, KWP 2000 uses one wire for both diagnostics and control purposes, reducing wiring harness complexity. Furthermore, manufacturer-specific CAN protocols may also be supported; its communication protocol relies on layers 3-7 of OSI reference model.

KWP 2000 communication protocol is an ideal choice for flash programming ECUs, offering faster data transmission rates than other automotive protocols and being easier to comprehend and utilize than UDS diagnostic communication protocol, which can be more complex.