OnStar Power Consumption - keywords battery digital discharge drain draw parasitic VCIM
| Subject: | OnStar® Power Consumption |
| Models: | 2000 - 2009 OnStar Equipped vehicles with Digital Hardware |
The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.
Condition/Concern:
During battery parasitic drain testing, there may be some confusion as to the normal power consumption reading from the OnStar® system.
Recommendation/Instructions:
When performing current draw tests it is important to understand the power cycles of the various OnStar® systems. All OnStar® customers with currently active vehicles have digital/analog cellular capability. A green status LED on the OnStar® keypad normally indicates an active OnStar® account. A red LED indicates a system DTC. On Gen 6 and later systems, a clear, or "dark" LED may indicated the OnStar® system has been deactivated or may possibly have a no power concern/no communication.
The OnStar® system will stay powered up after ignition off for an extended time in order to allow for remote services like door unlock, horn honk, light flash, etc to take place as requested by the customer. Power cycle (also referred to as DRX) times vary depending on the generation of the OnStar® system. Technicians may identify the system generation by using a Tech 2 (Body>VCIM>Module ID Information>Module Information 2) or by using www.onstarenrollment.com.
All Gen 6, Gen 7, and 8 systems are powered up continuously for 48 hours from ignition off. After the 48 hours the Gen 6 and some Gen 7 power off; Gen 7.xxL, and all Gen 8 systems will enter a 9 minute OFF 1 minute ON power cycle for an additional 72 hours. At the beginning and end of the 1 minute ON stage, you may or may not experience a short spike of current at the beginning and at the end. This allows for calls from OnStar to be received by the system. After 120 hours from ignition off, these systems then completely power off.
The expected current draw of the OnStar® module is:
| • | IGN ON - 240 to 400 mA |
| • | IGN OFF - 3 to 20 mA for 48 hours |
| • | IGN OFF - after 48 hours (120 hours on specified VCPs) - 0.2 to 0.8 mA |
| • | During extended voltage monitoring for platform battery parasitic it is possible that you may see a voltage spike caused by a cellular registration call that was triggered by the local cellular system, or that OnStar® has set a monthly trigger for a vehicle data upload call for the OnStar® Vehicle Diagnostic email upload. Note that in analog cellular markets all module generations completely power down after 48 hours. You can contact Technical Assistance to find out if your dealership cellular market or the customer's home cellular market still has analog service. |
Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.
