ECU Engine Sim

ECU Engine Sim transforms your Android device into a virtual car engine controller for OBD-II software development and testing. Connect two Bluetooth-paired Android devices—one running this app as the ECU simulator, the other running an OBD-II diagnostic tool—to test and validate your automotive software without needing a real vehicle.

Develop and test OBD-II applications indoors at your own pace. The simulator runs stably and reliably, emulating the ISO 15765-4 CAN 11/500Kb OBD-II standard. This eliminates the cost and complexity of test-driving with actual vehicles during development cycles. The app has been validated with leading OBD-II readers including Code Reader Pro, Torque Pro, DashCommand, and ELMScanToyota, delivering consistent results across multiple platforms.

The simulator operates as a data server, listening for AT and OBD-II command requests from external diagnostic testers, processing them, and returning appropriate responses. It supports most AT commands commonly used with the ISO 15765-4 CAN standard, including ATZ, ATWS, ATSP0, ATH0, ATH1, ATE0, ATE1, ATDP, ATRV, ATCAF0, and ATCAF1. The app also works seamlessly with command-line interfaces on Android terminal applications, giving developers flexibility in how they test and interact with the simulation.

Full OBD-II command support includes live data parameter IDs (PIDs) for engine speed, throttle position, fuel pressure, and vehicle speed; vehicle information queries for VIN numbers and calibration data; diagnostic trouble code retrieval and clearing; and freeze frame data capture. On the main data screen, you can live-adjust visible parameters for testing scenarios while other data returns fixed, realistic values.

Setup is straightforward. After launching the app, tap "Start simulating the ECU" to begin. The display shows your device's Bluetooth adapter name and address, which the simulator uses to emulate an ELM327 Bluetooth adapter that OBD-II apps recognize and connect to. For terminal-based testing, initialize the adapter with standard AT commands (ATZ to reset, ATSP6 to set protocol), then send OBD-II requests as needed.

Note: Some OBD-II apps with strict Bluetooth signal threshold detection may not connect due to differences between real ELM327 adapters and Android's Bluetooth Low Energy thresholds. ECU Engine Sim is designed for developers who need a cost-effective, lab-based testing environment before real-world deployment.