B1446 on 2009-2010 Saturn VUE: OnStar Backup Battery Failure Causes and Fixes

What's Unique About the 2009-2010 Saturn VUE

The 2009-2010 Saturn VUE belongs to the second generation, which shares its GM Theta platform and electronics with other vehicles of the era like the Chevrolet Equinox and GMC Terrain. For these vehicles, the OnStar backup battery has a finite lifespan, typically lasting 5-7 years. As these vehicles are now well over a decade old, the failure of the original backup battery is not just common, but expected. The provided Technical Service Bulletins (TSBs) from the manufacturer confirm that this is a well-documented issue across many GM models using this system.

Diagnostic Flowchart

Tap your situation to follow the diagnostic path that matches what you're seeing on this vehicle.

Symptoms You May Notice

• Solid or flashing red light on the OnStar buttons (typically on the rearview mirror).
• "Service OnStar" message may appear on the Driver Information Center (DIC).
• Inability to use any OnStar services.
• OnStar system may give a voice prompt indicating a problem when a button is pressed.

Most Likely Causes

1. Failed OnStar Backup Battery 🔴 High Probability → Shop Vehicle Battery The backup battery is a non-rechargeable lithium component with a finite chemical lifespan of roughly 5-10 years. On a vehicle of this age, the original battery is far beyond its expected service life and failure is inevitable. This is a common service item on aging GM vehicles.
   How to confirm: The presence of code B1446 combined with a red OnStar status light is the primary confirmation. Given the age of the vehicle and high failure rate, this is almost certainly the cause if the battery is original.
   Typical fix: Replace the OnStar backup battery. This involves accessing the Vehicle Communication Interface Module (VCIM), opening it, and swapping the old battery for a new one.
   Est. part cost: $40-$90
2. Improper Service Procedure ⚪ Low Probability As detailed in TSB PIC4541F, if the main vehicle battery is disconnected or the OnStar fuse is removed while the ignition is ON or Retained Accessory Power (RAP) is active, the VCIM activates the backup battery. This is a one-time, irreversible event that drains the battery completely, requiring replacement. This can happen during unrelated repairs if a technician is not careful.
   How to confirm: If the B1446 code appeared immediately after the vehicle's main battery was replaced or other electrical service was performed, this is a likely cause.
   Typical fix: Replace the OnStar backup battery. The damage from the premature discharge is permanent.
   Est. part cost: $40-$90

Rare But Worth Checking

• Faulty OnStar Module (VCIM): → Shop Telematics Interface Module If replacing the backup battery does not resolve the code, the module itself may have an internal fault. This is uncommon.
• Wiring or Connector Issue: Damage to the wiring harness leading to the VCIM could cause this code, but it's extremely unlikely unless other repair work was recently performed in the area.

Diagnosis Steps

1. Confirm the presence of code B1446 using an OBD-II scanner capable of reading Body (B) codes.
2. Observe the OnStar status light on the rearview mirror. A solid red light is a key symptom.
3. Based on the vehicle's age, proceed with the assumption that the backup battery has failed.
4. Locate the OnStar module (VCIM). On the 2009-2010 Saturn VUE, the VCIM is located under the rear passenger seat. You will need to lift the lower seat cushion to access it.
5. IMPORTANT: Turn the ignition completely OFF. Open the driver's door to disable Retained Accessory Power (RAP). Wait at least 10-15 minutes to ensure the vehicle is fully powered down before proceeding. Disconnecting the module with power active can permanently damage the new battery.
6. Disconnect the main vehicle battery as an extra precaution.
7. Lift the rear passenger seat cushion. You may need to release clips or hooks to flip it forward.
8. The VCIM is a silver metal box. The backup battery is a smaller black module attached to it.
9. Disconnect the wiring harnesses from the VCIM. You may need a small flathead screwdriver to release the locking tabs.
10. Remove the VCIM from the vehicle. It is typically held in place by 10mm bolts.
11. Carefully open the VCIM case (often with Torx T15 screws) to access the internal backup battery.
12. Replace the old battery with the new part, ensuring it is connected correctly. The original battery may be branded 'Ultralife'.
13. Reassemble the VCIM, reinstall it in the vehicle, and reconnect all wiring.
14. Reconnect the main vehicle battery.
15. Clear the trouble codes with a scan tool. The OnStar light should turn green after the system initializes (this may take a minute). The code should clear on its own after several ignition cycles if a scanner is not available.

Parts You'll Likely Need

• OnStar Backup Battery (OEM #88861186) — This is the component that fails due to age, triggering code B1446. It is a non-rechargeable, single-use battery designed to be replaced.
  Trusted brands: ACDelco, Dorman (e.g., 926-031, though application should be verified), Ultralife (often the original internal battery manufacturer)
  OEM price range: $60-$95
  Aftermarket price range: $40-$70

Related Codes That Often Appear With This One

• B1447 — This code also relates to the OnStar backup battery, specifically an 'Open Circuit' condition. TSBs from GM often list B1446 and B1447 together as they point to the same failed component.

Technical Service Bulletins (TSBs) & Recalls

• PIC4541F: Provides a diagnostic tip for OnStar back-up battery failure causing B1446 or B1447. Warns against disconnecting power while ignition or RAP is active.
• PIC5141A: Mentions that B1446 or B1447 can appear after module replacement or a Canada-specific upgrade, requiring a call to GM technical support.

Platform-Specific Known Issues

• GM Technical Service Bulletin #PIC4541F directly identifies Diagnostic Trouble Code B1446 as being caused by an OnStar back-up battery failure, accompanied by a red OnStar LED. It contains the critical warning about powering down the vehicle before service.
• GM Technical Service Bulletin #PIC5141A notes that B1446 can also appear after a module replacement or software update, which may require assistance from GM Technical Assistance to resolve.
• A YouTube video by 'Mongo Fix' specifically shows the VCIM location for a 2009 Saturn Vue as being under the rear passenger seat, requiring the seat cushion to be lifted for access.

Mechanic-Grade Diagnostic Values

• Backup Battery Voltage at VCIM Connector X1 — expected: Greater than 15.5 V. Failure: Voltage is less than the specified value, indicating a failed battery or circuit issue.
• Main System Voltage (Condition for running DTC) — expected: Between 9.5 and 15.5 V. Failure: The VCIM will not run the backup battery diagnostic if the main system voltage is outside this range.

Hidden / Shadow Codes Worth Checking

• B1446 03: Replace Backup Power Source Voltage Below Threshold. This is a symptom byte that explicitly confirms the VCIM has detected the backup battery's voltage is too low. (see via A professional GM-specific scan tool, such as a Tech 2 or GDS2, is required to view symptom bytes.)
• B1447 04: Backup Power Source Open Circuit. This code often sets alongside B1446 and indicates the battery is completely disconnected, internally failed, or dead. (see via A professional GM-specific scan tool, such as a Tech 2 or GDS2.)

Scan Tool Commands That Help

• GM GDS2 / Tech 2: Module Diagnostics -> VCIM -> DTC Information — Use this function to confirm the presence of B1446 and view the specific symptom byte (e.g., '03') to verify the exact failure mode before ordering parts.
• GM SPS (Service Programming System): VCIM Vehicle Communication Interface Module Set-up — This function is required if the entire VCIM module is replaced, not just the battery. It configures the new module to the vehicle. TSB PIC5141A notes that issues after this procedure may require a call to GM Technical Assistance.

Wiring & Ground Locations

• VCIM Connector X1, Pin 14 — On the main wiring harness connector for the Vehicle Communication Interface Module (VCIM), located under the rear passenger seat.. This pin is the 'Battery Backup Supply Voltage Circuit'. It is the positive terminal for testing the backup battery's voltage directly at the module's input.
• VCIM Connector X1, Pin 13 — On the main wiring harness connector for the Vehicle Communication Interface Module (VCIM), located under the rear passenger seat.. This pin is the 'Battery Backup Low Reference Circuit'. It serves as the ground/negative pin for testing the backup battery's voltage. A voltage test between pin 14 and pin 13 confirms the battery's state.
• G301 — Under the left front seat.. This is a major chassis ground point located in the general vicinity of the VCIM (which is under the rear seat). While a bad ground is a very unlikely cause for this specific battery code, a technician chasing an unusual electrical fault in this area after replacing the battery might check this ground for corrosion or looseness.