Circuit Description
WARNING: This page is about a different car, the 1998 Pontiac Grand Prix, 1998 Chevrolet Monte Carlo, 1998 Chevrolet Lumina, and 1998 Buick Century. However, it is still accessible from the selected car via links, so may be relevant.
A Class II serial data communications system is used on these vehicles to allow various modules to communicate and share information with each other. Each bit of information has 2 lengths, long or short. This allows vehicle wiring to be reduced and the transmission and reception of multiple signals over a single wire. The messages carried on a Class II serial data streams are also prioritized. If two messages attempt to establish communications on the data line at the same time, the message with a higher priority will continue. The message with a lower priority will wait. If a module cannot respond to the PCM, a DTC will set.
Conditions for setting DTC:
- Ignition on.
- System voltage greater than 8.2 volts.
- PCM cannot communicate with EBCM.