Service Vehicle Indicator

The service vehicle indicator is controlled by the following:
^ The Powertrain Control Module (PCM)
^ The instrument cluster

The PCM sends a Class 2 message through circuit 1036 to the instrument cluster to turn on the indicator when problems with the engine have been detected.

The instrument cluster turns on the service soon indicator under the following conditions:
^ Class 2 communication has been lost between the instrument cluster and any other module. (PCM, SDM, EBCM)
^ The air bag indicator is defective. DTC B0670 is set.
^ For approximately 3 seconds at bulb test.