ISO 9141 Communications Network
WARNING: This page is about a different car, the 2008 Mercury Sable, 2008 Ford Taurus X, and 2008 Ford Taurus. 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 and is used for diagnostic use only. The only module on the ISO 9141 network is the PAM. When the scan tool communicates to the PAM, 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 |