Ohmic Audio

🔧 INSTALLER LEVEL: Installation and Bypass Modules

Bypass Module Selection

Illustration in preparation Description: Complex wiring diagram showing bypass module connected between vehicle immobilizer, remote start module, and ignition harness with all wire functions labeled

Modern vehicles have immobilizers (transponder keys, push-button start). The vehicle ECU verifies a chip in the key before allowing the engine to start. Remote start doesn't have this chip.

Bypass module tricks the immobilizer by: - Storing the key's transponder signal when programmed - Presenting this stored signal to the immobilizer when remote start activates - Releasing control back to physical key when driver enters

Brand matching:

Bypass modules are often brand and module specific:

Always use a vehicle-specific harness when available. These plug directly into the factory connectors without cutting wires. Non-destructive, fully reversible.

Programming bypass:

Most bypass modules require an initial programming procedure: 1. Place physical key near bypass module antenna (3–5 seconds) 2. Module reads transponder signal and stores it 3. Verify: Start vehicle with stored signal (remote start test) 4. On success, module is ready

Alarm Zone Wiring

Door trigger wiring:

Most vehicles have a "door pin switch" circuit — a wire that goes to ground when any door opens (triggers dome light). Connect this to the alarm module's "door input" terminal.

Some vehicles use a positive-pulse door signal. Check with voltmeter: does voltage go up or down when door opens?

Hood pin:

Simple normally-closed switch. When hood closed: circuit closed. When hood open: circuit opens. Connect to alarm hood input. Alarm triggers if hood opened while armed.

Shock sensor calibration:

Illustration in preparation Description: Diagram of two-stage shock sensor calibration, showing sensitivity adjustment and warning zone vs alarm zone thresholds

Two-stage shock sensors have two sensitivity levels: - Stage 1 (warning): Light impact → single chirp warning, no full alarm - Stage 2 (alarm): Hard impact → full alarm

Calibration procedure: 1. Install with moderate sensitivity 2. Tap vehicle lightly — should trigger Stage 1 only 3. Tap firmly — should trigger Stage 2 4. If too sensitive: false alarms from wind, large trucks passing 5. If not sensitive enough: Miss actual tampering

Field-tune in the actual parking environment — a sensitive setting appropriate for a garage may be inappropriate for a busy parking lot.

Telematic Systems and GPS Tracking

GPS receiver:

Module receives GPS position from satellites (L1 frequency, 1575.42 MHz). Accuracy: 2–5 meters horizontal with good sky view.

Cellular modem:

Sends GPS coordinates and vehicle status to server. Uses 4G LTE (most modern systems). Communication: AES-encrypted HTTPS to manufacturer's cloud server.

Vehicle interface:

Geofencing:

Define a geographic boundary on a map. System alerts when vehicle leaves or enters the zone. Useful for: - Teen driver monitoring - Fleet management - Theft detection (notification if vehicle moves while parked)

Subscription economics:

Most telematic systems charge $3–15/month for cloud service and cellular connectivity. Over 5 years: $180–$900. Evaluate whether features justify cost for your use case.

For theft recovery specifically: Consider that a GPS unit with tracking costs ~$200 installed + subscription. Compare to comprehensive insurance deductible. For high-value vehicles, the math often works.