Service Interaction Protocol

Timing Parameters

0x83

Protocol Identifier

Read and modify the link-layer timing parameters (P2 and P2*) to optimize communication speed or handle slow ECU operations.

A Service Identifier (SID) is a single-byte value (0x00–0xFF) in position 0 of every UDS request frame. It specifies which diagnostic operation the client wishes the ECU to execute. The positive response echoes the SID with the high bit set (SID + 0x40).

P2_SERVER

50ms

Standard response timeout. ECU must acknowledge within this window.

P2_STAR

5000ms

Extended timeout used after NRC 0x78 (Response Pending) is received.

LATENCY

LOW

Optimizing these values can significantly speed up high-volume data transfers.

Overview

ISO 14229-1

“The AccessTimingParameter service is used to read and change the default timing parameters of a diagnostic session.”

info _entry

P2Server (Default: 50ms)
The maximum time the tester waits for any response from the ECU. If the ECU cannot process execution within this time, it must send an NRC 0x78 (Pending).

warning _entry

P2*Server (Default: 5000ms)
The extended timeout used only after an NRC 0x78 is received. Defines how long the tester waits for the final result of a long operation.

Default Behavior

Timing parameters are session-specific. When the ECU is in the Default Session (0x01), it uses OEM-standard default values (e.g., P2=50ms). Transitions to Extended (0x03) or Programming (0x02) sessions may automatically activate a different timing set. Service 0x83 allows temporary overriding of these values until the session is reset.

Protocol Anatomy (Read Capabilities)

◆ PROTOCOL ANATOMY

View

REQUEST_TX

0x83 TIMING PARAMETERS

RESPONSE_RX

0x83 RESPONSE

Validation Logic

Workflow: Reading and Overriding Timing

4 steps

Tester

ECU

Click to Enlarge

Logic flow for validating and applying new timing parameters.

Negative Response Codes

Error_Catalog

Negative Response Codes

THREAT_LEVEL2 HIGH1 MEDIUM3 NRCs TOTAL

ISO_14229_ANNEX_ANRC_ENGINE_V2