Circuit/System Description

WARNING: This page is about a different car, the 2015 Cadillac SRX. However, it is still accessible from the selected car via links, so may be relevant.

The devices connected to the low speed GMLAN serial data circuits monitor for serial data communications during normal vehicle operation. The serial data is transmitted over a single wire to the appropriate devices. The transmission speed for GMLAN low speed is up to 83.33 kbit/s. Under normal vehicle operating conditions, the speed of the bus is 33.33 kbit/s. The devices toggle the serial data circuit between 0-5 V during normal communications. To wake the devices connected to the low speed GMLAN serial data circuit, a voltage wake up pulse of 10 V is sent out. If serial data is lost, devices will set a no communication code against the non-communicating device. A loss of serial data communications DTC does not represent a failure of the device that set it.