An aftermarket telematics unit (“ATU”) for use with a telematics service system having a call center is disclosed herein. The ATU is adapted for mounting to a vehicle and is configured for operation in an on-mode, a standby-mode, and an off-mode. The aftermarket telematics unit includes, but is not limited to, a memory unit and a processor that is operatively connected to the memory unit. The processor is configured to send a first notification to the call center when a number of transitions from the off-mode to the on-mode experienced by the ATU exceeds a predetermined number during a first predetermined length of time. The processor is further configured to send a second notification to the call center when the ATU has been continuously operating in the on-mode for greater than a second predetermined length of time.