Remote Vehicle Start Circuit Description

WARNING: This page is about a different car, the 2010 GMC Terrain and 2010 Chevrolet Equinox. However, it is still accessible from the selected car via links, so may be relevant.

The BCM receives a signal from the keyless entry transmitter indicating a remote vehicle start request. A message is then sent to the BCM which determines if a crank request message will be sent to the ECM to allow engine starting. To determine if conditions are correct for an remote vehicle start event, the BCM will ensure the following conditions are met:

All vehicle doors are closed.
A valid hood ajar switch closed signal is present.
The doors are locked.
The hazard switch is OFF.
The vehicle power mode is correct.
No content theft deterrent alarm triggers are present.
The vehicle is not in valet mode, if equipped.

When the BCM determines all conditions meet those required for an remote vehicle start event, a message is sent via serial data to the ECM. The ECM relies on the remote vehicle start message from BCM to enable remote vehicle start when the crank request signal is received. If the ECM does not receive a valid remote vehicle start message, it will not attempt to start the engine. While the ECM is in remote vehicle start mode it will suspend engine operation if any of the following additional conditions occur:

Vehicle speed is greater than 0.
Transmission is not in PARK.
Excessive engine coolant temperature
Low oil pressure
The malfunction indicator lamp (MIL) is commanded ON.
Engine crank time is greater than 30 seconds.
Excessive engine speed
Accelerator pedal position too high
Remote start timer equals 0.
Immobilizer system indicates tamper