PIC4935F

Bulletin No.: PIC4935F
Published date: 02/24/2017
Preliminary Information
PIC4935F Normal Characteristic - OnStar Power Consumption
Models
Brand:
All
Model:
All
VIN:
Model Years:
2000 - 2017
from
All
Engine:
to
All
All
Transmissions:
All
With OnStar Gen6, Gen7, Gen8, Gen9, and Gen10
Supersession Statement
This PI was superseded to update model years, and gen10 information. Please discard PIC4935D.
The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.
Condition / Concern
During battery parasitic drain test, there may be some confusion as to what the normal power consumption reading should be from
the OnStar® system.
Recommendations / Instructions
When performing a current draw test it is important to understand the power cycles of the various OnStar® systems. All OnStar®
customers with active accounts on their vehicles have digital 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 dark or no LED lit
may indicate the OnStar® system has been deactivated or possibly it may have a no power/no communication concern.
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 using GDS/GDS 2 (Telematics
Communication Interface Control Module/ Identification Information.
All Gen 6, 7, 8, and 9 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.
Gen9 and FCP1 (Volt) will remain in that mode for 120 hours (5 days). At the beginning and end of the 1 minute ON stage, you may
experience a short spike of current. 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 and in DRx (Stand by mode) - 3 to 20 mA for 48 hours on Gen 6,7, 8, or 120 hours on Gen9, FCP1 (Volt), and specified VCP's
• IGN OFF and after DRx has been canceled - 1 to 3 mA after 48 hours on Gen 6,7, 8, or 120 hours on Gen9, FCP1 (Volt), and
specified VCP's
Gen 10 from the factory is set to 4 days DRx (Stand by mode) with (no active service). At time of subscriber activation, DRX
mode changes to 10 days.
If DRx mode is active, module current draw may be 3-20 mA.
Once DRx mode times out (after the 4 or 10 day time frame), the parasitic draw should be 1-3 mA.
• During extended current monitoring for platform battery parasitic it is possible that you may see an amperage 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.
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.
© 2016 General Motors. All Rights Reserved.