ISO 9141 Communications Network
WARNING: This page is about a different car, the 2007 Mercury Mariner and 2007 Ford Escape. However, it is still accessible from the selected car via links, so may be relevant.
The ISO 9141 communications network is a single wire network. The ISO 9141 communications network does not permit intermodule communication. The ISO 9141 is used for the restraints control module (RCM) and the parking aid module. The ISO 9141 is used for diagnostic use only. When the scan tool communicates to the RCM or the parking aid module, the scan tool must request all information, the module cannot initiate communications.
The following fault chart describes the specific ISO 9141 network failures and their resulting symptom:
ISO 9141 NETWORK COMMUNICATION FAULT CHART
| Failure Description | Symptom |
|---|---|
| ISO circuit open | No communication |
| ISO circuit short to voltage | No communication |
| ISO circuit short to ground | No communication |
| Module loss of voltage or ground | No communication |
| Module internal failure | No communication |