B1447 on 2010-2017 Buick LaCrosse: OnStar Backup Battery Failure Explained

What's Unique About the 2010-2017 Buick LACROSSE

This issue is not unique to the LaCrosse but is common across a vast range of GM vehicles from the 2010s, including Buick, Cadillac, Chevy, and GMC models. The OnStar backup batteries have a finite service life, typically 3-7 years. As these vehicles have aged, battery failure has become a routine maintenance issue. 🎬 Watch: Step-by-step guide to replacing the OnStar backup battery. The key difference for this platform is the location of the OnStar module, which changed between the second (2010-2016) and third (2017) generations, affecting the repair's difficulty.

Diagnostic Flowchart

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

Generation note: This range covers the second generation (2010-2016) and the first year of the third generation (2017) LaCrosse. On second-generation models, the OnStar module is commonly found in the trunk, mounted to the underside of the rear package tray, making access relatively easy. The location on third-generation models is likely behind the dashboard or glove compartment, similar to other GM vehicles of that era like the Chevy Equinox, which is more difficult to access.

Symptoms You May Notice

• A solid red light on the OnStar indicator panel in the overhead console or rearview mirror.
• A 'Service OnStar' message appearing on the Driver Information Center (DIC).
• OnStar services being completely non-functional.
• Receiving a diagnostic alert email or notification from OnStar about the issue.

Most Likely Causes

1. OnStar Backup Battery (BUB) Failure 🔴 High Probability → Shop Vehicle Battery The backup battery is a non-rechargeable lithium battery with a limited service life. After 5-7 years, natural degradation causes it to fail, which is a common occurrence noted by owners.
   How to confirm: A red OnStar LED combined with a scan confirming DTC B1447 is a definitive diagnosis. Calling OnStar may also allow them to run a remote diagnostic to confirm the failure.
   Typical fix: Replace the OnStar backup battery, which is located inside the OnStar/VCIM module. The module itself is opened to swap the battery.
   Est. part cost: $40-$80
2. Improper Main Battery Disconnection ⚪ Low Probability → Shop Vehicle Battery This is a user-induced failure. Per TSB PIC4541F, if the main vehicle battery is disconnected while the ignition is ON or Retained Accessory Power (RAP) is active, the OnStar module interprets it as a crash and activates the backup battery. This action permanently drains the non-rechargeable backup battery.
   How to confirm: If the B1447 code appeared immediately after the main vehicle battery was replaced or disconnected for service.
   Typical fix: Replace the OnStar backup battery. The previous battery was likely good but was depleted by the incorrect service procedure.
   Est. part cost: $40-$80

Rare But Worth Checking

• Backup Battery Internal Protection Activated: → Shop Vehicle Battery

Diagnosis Steps

1. Verify the symptom: Check if the OnStar status light is red.
2. Scan the vehicle's Telematics Communication Interface Control Module for codes. Confirm that B1447 is present.
3. CRITICAL: Before any repair, turn the ignition OFF. To ensure Retained Accessory Power (RAP) is inactive, open and close the driver's door and wait for all interior lights to turn off. Failure to do this before disconnecting power will drain the new battery instantly.
4. Locate the OnStar (VCIM) module. For 2010-2016 models, check the underside of the package tray in the trunk, accessible by removing trunk liner panels. For 2017 models, prepare to look behind the glove box or lower dash panels, likely on the passenger side.
5. Disconnect the main harness connector(s) from the OnStar module.
6. Remove the module from the vehicle. It is typically held by a few bolts or screws.
7. Open the module's plastic casing to access the internal backup battery.
8. Disconnect and replace the battery, ensuring the new one is connected correctly.
9. Reassemble the module, reinstall it in the vehicle, and reconnect the harness.
10. Clear the DTC with a scan tool. The OnStar light should turn green after a short initialization period.

Parts You'll Likely Need

• OnStar Backup Battery (OEM #23117460) — This is the component that has failed and triggered the B1447 code. It is a consumable part that fails with age. Part number 23117460 is cited for 2013-2016 GM vehicles and is listed as compatible with the LaCrosse. Older part numbers like 88861186 or 22704633 may apply to earlier models but have likely been superseded.
  Trusted brands: ACDelco, Genuine GM
  OEM price range: $50-$80
  Aftermarket price range: $40-$60

Related Codes That Often Appear With This One

• B1446 — This is another GM code for OnStar backup battery failure. B1446 typically sets when the battery voltage drops below a certain threshold, while B1447 sets when the module detects a complete open circuit (no voltage at all). They point to the same root cause and are often listed together in service bulletins.

Technical Service Bulletins (TSBs) & Recalls

• PIC4541F: Provides diagnostic information for OnStar backup battery failure, linking it to DTCs B1446 and B1447 and a red OnStar LED. It contains a critical warning about not disconnecting power while the ignition or RAP is active and lists dozens of affected GM models.
• PIT5463B: A preliminary information bulletin for older GM models that also references DTC B1447 after certain OnStar upgrades, instructing technicians to install a new Back Up Battery (BUB).

Platform-Specific Known Issues

• The location of the OnStar module varies by generation. 2010-2016 models typically have it in an accessible location in the trunk, making for a sub-1-hour repair. 2017 models may have it buried in the dashboard, significantly increasing the labor time and difficulty for replacement.

Mechanic-Grade Diagnostic Values

• Conditions for Setting DTC B1447 — expected: The VCIM detects no voltage from the back-up battery.. Failure: The VCIM detects an open/high resistance in the battery backup voltage supply circuit or ground circuit, or a short to voltage.
• Conditions for Setting DTC B1446 (related code) — expected: Backup battery voltage is above the minimum threshold.. Failure: The backup battery voltage has dropped below the minimum threshold value, or the VCIM detects a short to ground in the supply circuit.

Hidden / Shadow Codes Worth Checking

• B1447 04: This code with a '04' symptom byte (indicating an open circuit) was noted in a TSB related to OnStar upgrades on other GM vehicles, instructing technicians to install a new backup battery. (see via A professional scan tool like GM GDS2 that can read DTCs with symptom bytes.)

Scan Tool Commands That Help

• GDS2: ID Information Screen (in Battery Energy Control Module menu) — While not directly for the OnStar battery, this function is used on other GM modules to read the 16-digit Battery Identification Number (BIN) without physically removing the module. This indicates the GDS2 has deep communication ability with battery modules that may extend to reading parameters on the VCIM.
• GDS2: Clear DTCs — After replacing the backup battery, a scan tool is required to send the 'clear DTC' command to the VCIM. The code will not clear on its own immediately and will move to history status only after 50 malfunction-free ignition cycles.

Wiring & Ground Locations

• VCIM Ground Wire — For a 2011 LaCrosse, the main ground wire for the audio system (which integrates OnStar) is specified as Black/Lt. Green.. While the B1447 code is almost always the battery itself, a poor main ground to the VCIM could cause a variety of electrical issues. Verifying this ground is secure is a valid, though unlikely, diagnostic step if battery replacement does not solve the issue.
• VCIM Connector X1 (or C1) — The main harness connector on the VCIM module.. Service information specifically warns to disconnect this connector first before any other connectors on the module. This ensures the backup battery circuit is properly depowered and prevents accidental discharge of the new battery during service.

Real Owner Repair Stories

• Reddit user deadhorsegaming on r/volt (2012 Chevrolet Volt (uses a similar OnStar module)) — Main 12V vehicle battery draining every 2-3 days. Pulling the OnStar fuse stopped the drain but disabled Bluetooth and compass.
  ❌ Tried (didn't work) Replacing the main 12V battery did not fix the parasitic drain.
  ✅ What actually fixed it The user went to a junkyard, pulled an OnStar module from a Buick, and swapped it into their Volt. This restored Bluetooth and compass functionality and resolved the parasitic battery drain. This suggests a failure mode where the VCIM itself can fail and cause a drain, though the B1447 code is typically just the internal battery.

OEM Part Supersession History

• 19118855, 22704633, 42454411 → 88861186 — Standard part evolution and consolidation by GM over many model years.
  Heads up: These older numbers are frequently replaced by 88861186, which itself may be superseded in some applications by newer numbers like 23117460. Always verify with a dealer using the VIN.
• 88861186 → 23117460 (in some applications) — Likely related to updates in battery chemistry or connector design for newer generation OnStar modules.
  Heads up: While 23117460 is listed for many 2013+ vehicles, 88861186 is still sold and specified for many others. Compatibility is not guaranteed without checking the specific vehicle's build.