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.
Principles of Operation: Ms-Can
The MS-CAN network uses an unshielded twisted pair cable of data (+) and data (-) circuits. The data (+) and the data (-) circuits are each regulated to approximately 2.5 volts during neutral or rested network traffic. As bus messages are sent on the data (+) circuit, voltage is increased by approximately 1.0 volt. Inversely, the data (-) circuit is reduced by approximately 1.0 volt when a bus message is sent. Multiple bus messages can be sent over the network CAN circuits allowing multiple modules to communicate with each other. The MS-CAN is used for the instrument cluster, the audio control protocol (ACP) module and the smart junction box (SJB) communications, and designed for general information transfer. The MS-CAN network will not communicate while certain faults are present, but will operate with diminished performance with other faults present. The MS-CAN bus may remain operational when 1 of the 2 termination resistors are not present.
The following fault chart describes the specific MS-CAN network failures and their resulting symptom:
| Failure Description | Symptom |
|---|---|
| MS-CAN (+) shorted to MS-CAN (-) | No communication |
| MS-CAN (+) short to voltage | No communication |
| MS-CAN (-) short to voltage | No communication |
| MS-CAN (+) short to ground | No communication |
| MS-CAN (-) short to ground | Unreliable communication |
| MS-CAN (+) open | Unreliable communication |
| MS-CAN (-) open | Unreliable communication |
| Module loss of voltage or ground | No communication |
| Module internal failure | No communication |
NO RELATED
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
Affiliate disclosure: We may earn a commission at no extra cost to you.
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.