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.
The Optical Connector
| Terminal | Signal type | Miscellaneous |
| 1/B1 | Optical input signal | Input signal for MOST communication |
| 2/B2 | Optical output signal | Output signal for MOST communication |
Each control module in the MOST network has an optical connector which consists of two diodes, a sender diode and a receiver diode. These transmit and receive light pulses.
The actual communication between two control modules is as follows. A sender diode transmits the message as a light pulse. This is transmitted from the control module via the MOST network to a photo-optical receiver diode in the receiving control module.
The two optical terminals in the connector are numbered in the same way on all control modules in the MOST network. There are two sizes of switch that the two optical terminals are mounted in. One with a connector with integrated power supply is integrated with the optical terminals and the other has a connector with only the optical terminals.
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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.
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