Service Interaction Protocol

ECU Reset

0x11

Protocol Identifier

The ECU Reset service is used to request a reset of the server (ECU), simulating various power-cycle or software restart scenarios.

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).

RESET_SCOPE

SYSTEM

Resets affect both application software and hardware states depending on the requested type.

POWER_CYCLE

SIMULATED

Hard Reset (0x01) triggers full re-initialization of all volatile memory and security states.

RESPONSE_TIMING

IMMEDIATE

ECU typically sends a positive response before executing the actual reset transition.

warning _entry

Reset Side Effect: A Hard Reset (0x01) or Key Off/On Reset (0x02) will almost always revert the ECU to the Default Diagnostic Session (0x01) and lock Security Access.

Overview

ISO 14229-1

“The ECU Reset service requests the server to perform a reset. The server shall simulate a specific reset condition based on the sub-function parameter.”

Default Behavior

At startup, the ECU is in a “Running” state. It does not perform any resets unless explicitly requested via service 0x11. A successful Hard Reset (0x01) will return the ECU to its initial boot state, typically reverting to the Default Session (0x01) and resetting all security and session persistence.

Protocol Anatomy

◆ PROTOCOL ANATOMY

View

REQUEST_TX

0x11 ECU RESET

RESPONSE_RX

0x11 RESPONSE

Reset Types (Sub-Functions)

Hard Reset (0x01)

Simulates a full power cycle. Initializes both hardware and software layers. All volatile memory is cleared.

tx_packet

Request

11 01

Key Off/On Reset (0x02)

Simulates turning the ignition key off and back on. Typically used to apply new configuration parameters.

tx_packet

Request

11 02

Soft Reset (0x03)

Restarts the application software without a full hardware reset. Faster than a hard reset.

tx_packet

Request

11 03

Enable Rapid Power Shutdown (0x04)

Prepares the ECU for an immediate shutdown, bypassing normal shutdown sequences.

tx_packet

Request

11 04

Reset Behavior & Side Effects

Click to Enlarge

Visual flow of the ECU Reset process, including validation and reset execution.

Aspect	Hard Reset (0x01)	Soft Reset (0x03)
Session State	Reverts to Default (0x01)	May persisit (Impl. dependent)
Security State	Locked	Locked
Volatile Memory	Cleared	Partially Preserved
Comm. Stack	Restarted	May remain active

Example Workflows

Workflow: Hard Reset Sequence

4 steps

Tester

ECU

Negative Response Codes

Error_Catalog

Negative Response Codes

THREAT_LEVEL4 HIGH1 MEDIUM5 NRCs TOTAL

ISO_14229_ANNEX_ANRC_ENGINE_V2