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.
Communications Network: Notes
Vehicle communication utilizes the International Standards Organization (ISO) 9141 network, the medium speed controller area network (MS-CAN), and the high speed controller area network (HS-CAN). Information is sent to and from individual control modules that each control specific functions. All 3 networks are connected to the data link connector (DLC). The DLC can be found under the instrument panel between the steering column and the audio control module (ACM).
The 3 module communication networks are:
- ISO 9141
- Medium speed (MS) CAN
- High speed (HS) CAN
All 3 networks are connected to the DLC. This makes diagnosis and testing of these systems easier by allowing one scan tool to be able to diagnose and control any module on the 3 networks from one connector. The DLC can be found under the instrument panel between the steering column and the ACM.
| Module Name | Network Type | Termination Module |
|---|---|---|
| ABS module (if equipped) | HS-CAN | No |
| Audio control module (ACM) | MS-CAN | No |
| Instrument cluster (IC) (gateway module) | HS-CAN MS-CAN |
Yes Yes |
| PCM | HS-CAN | Yes |
| Restraints control module (RCM) | ISO 9141 | N/A |
| Satellite digital audio receiver system (SDARS) module (if equipped) | MS-CAN | No |
| Smart junction box (SJB) | MS-CAN | Yes |
NO RELATED
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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.