Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Reference Waveform
CAN Communication Wave monitors signals from CAN High line and CAN Low line simultaneously.
The reference value for the High Speed CAN signal is 2.5V, which is in BUS IDLE state (DIGITAL 1). If it rises to 3.5V, it is considered 'High' whereas it sets 'Low' if it drops to 1.5V. "0" is detected when the difference between 'High' and 'Low' is greater than 2V. Also, the information can be used to determine if the 'High' and 'Low' display voltage values reverse to each other.
1 BIT can be detected by computing "SOF (Start of Frame)" that signals the beginning of a frame. It indicates an error when the "0" signal continues for over consecutive 6 BITs. Thus, check if this occurs.
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.