Getting Started Guide

Welcome to the UDS Simulator. This guide will walk you through the first 5 minutes of your diagnostic journey, from powering up the virtual ECU to reading live vehicle data.

1. Access the Simulator

Navigate to the Simulator  dashboard from the top navigation bar.

2. Power & Ignition

Ensure the system is ready for communication:

• Check the ECU Power indicator. It should be green.
• Verify the Ignition (KL15) status. If it’s red, toggle it to “ON”.
• The ECU starts in the Default Diagnostic Session (0x01).

3. Your First Request: Session Control (0x10)

Let’s elevate the diagnostic session to unlock advanced features.

1. Locate the Service Selector in the Request Builder panel.
2. Select DiagnosticSessionControl (0x10).
3. Choose Extended Diagnostic Session (0x03) as the sub-function.
4. Click the “SEND REQUEST” button.

Observe the Terminal

Watch the terminal output for the following frame exchange:

The status bar should now display “Session: EXTENDED”.

4. Reading Live Data (0x22)

Now that we are in an extended session, let’s read the current vehicle speed.

1. Change the Service Selector to ReadDataByIdentifier (0x22).
2. Select “Vehicle Speed” from the DID list (Identifier 0x0101).
3. Click “SEND REQUEST”.
4. Observe the Live Cluster — the speedometer should reflect the value read from the ECU.

5. Staying Connected (0x3E)

In non-default sessions, the ECU expects a “heartbeat” to remain unlocked. This is handled by Tester Present (0x3E).

• If you stop sending requests for more than 5 seconds, the S3 Timer will expire.
• The ECU will automatically reset to the Default Session.
• You can enable “Auto Tester Present” in the settings to maintain the connection automatically.

Next Steps

Now that you’ve mastered the basics, explore the detailed protocol specifications:

• 0x10 Diagnostic Session Control
• 0x27 Security Access
• 0x31 Routine Control