A small collection of standalone bash + can-utils scripts for CAN bus / OBD-II diagnostics on Linux (Raspberry Pi in-vehicle rigs, bench SocketCAN setups, etc.).

Each script is self-contained — no shared library, no framework, just SocketCAN (cansend / candump) and standard OBD-II services. Drop in whichever ones you want.

⚠️ Working on a live vehicle's CAN bus carries real risk. Writing the wrong bytes can set faults, disable systems, or in rare cases require a dealer reflash. Read each script's header, prefer --dry-run first, and start listen-only. These are provided as-is, no warranty — see Disclaimer.

Clears OBD-II Diagnostic Trouble Codes — the destructive-write counterpart to a read-only dtc.sh. Issues OBD-II Service 0x04 ClearDiagnosticInformation against the ECM on $7E0 / $7E8.

Clears stored DTCs (Mode 0x03), pending DTCs (Mode 0x07), freeze-frame data (Mode 0x02), and resets the emissions readiness monitors; the MIL (check-engine light) goes out immediately. Does not clear permanent DTCs (Mode 0x0A — regulatory, enforced inside the ECM) or non-OBD-II module codes (those need UDS Service 0x14).

Safety-first by design:

• Refuses to write without --yes — no interactive y/n to fat-finger
• --dry-run prints the exact cansend frame without sending
• Previews current DTCs first via dtc.sh (if on PATH); --skip-preview to skip
• Decodes NRC bytes on negative response (e.g. NRC 0x33 securityAccessDenied → SGW hint)

./dtc-clear.sh                 # preview only — refuses to clear without --yes
./dtc-clear.sh --dry-run       # show the cansend that would fire
./dtc-clear.sh --yes           # actually clear codes
./dtc-clear.sh --skip-preview --yes

Flags: [--yes|-y] [--dry-run] [--skip-preview] [--wait SEC] [--verbose] [--help]

A simple terminal dashboard that polls a curated set of standard OBD-II Mode 01 PIDs in a loop and redraws a fixed-size text frame each cycle. Tuned/labelled for the JEEP Gladiator (JT), but every PID is SAE J1979-standard, so it runs unchanged on any 2007+ OBD-II vehicle.

Polls 11 PIDs (~2.2s refresh): engine RPM, vehicle speed, throttle, absolute load, coolant / oil / intake / ambient temps, fuel level, run time, and control-module voltage (≈ battery V). A missing response shows -- for that field without crashing the dashboard.

./engine-dash.sh               # live dashboard, Ctrl+C to exit
./engine-dash.sh --once        # print one frame and exit (scripting / logs)

Standalone — issues Service 0x01 requests directly via cansend / candump with inline single-frame and first-frame PCI parsing. Only runtime dependency is can-utils.

• Linux with SocketCAN (mainline kernel; Raspberry Pi + a CAN HAT is a common rig)
• can-utils — apt install can-utils
• A CAN interface up at the bus bitrate, e.g.:

  ip link set can1 up type can bitrate 500000
  

Most scripts default to CAN_C=can1 (the OBD-II ECM bus); override via the environment variable if your wiring differs.

The scripts are committed as .txt so they render and download cleanly in a browser. To run them, save without the extension (or rename) and chmod +x:

mv dtc-clear.txt dtc-clear.sh && chmod +x dtc-clear.sh

These scripts pair with the CAN bus / OBD-II reference material at magikh0e.pl/pubCarHacking — message maps, UDS read/write guides, the Secure Gateway Module write-up, and a bus-and-message reference with the byte-level detail the script headers point at.

Informational / educational use only. Working on a vehicle's CAN bus can void warranties and, with write operations, cause real damage. You are responsible for what you send on your own bus. No warranty, express or implied.

MIT — see LICENSE if present, otherwise treat as MIT.