B1447 on 2014-2017 Chevrolet SS: OnStar Backup Battery Failure Causes and Fixes

What's Unique About the 2014-2017 Chevrolet CHEVEROLET SS

The Chevrolet SS, being a unique, low-volume vehicle based on the Australian Holden Commodore (VF), uses the same common GM OnStar hardware as many other North American models. As these vehicles age, the 3-7 year lifespan of the lithium backup battery expires, making this a very common and expected maintenance issue. The failure is not a design flaw of the SS itself, but rather the natural end-of-life for a consumable electronic component. The VCIM module in the SS is located in the trunk, behind the driver's side trim panel, making access relatively easy compared to other GM models where it might be behind the glovebox.

Diagnostic Flowchart

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

Symptoms You May Notice

• Solid red status light on the OnStar buttons (on the rearview mirror or overhead console).
• OnStar system may be non-functional, including hands-free calling or remote diagnostics.
• Inability of the OnStar system to run a remote diagnostic check.
• OnStar customer service may inform you there is a hardware fault and direct you to a dealer.

Most Likely Causes

1. Failed/Aged OnStar Backup Battery 🔴 High Probability → Shop Vehicle Battery The internal lithium battery has a finite service life, typically 3-7 years. As the 2014-2017 model year vehicles have aged, battery failure is now a common and expected issue across the GM lineup.
   How to confirm: A scan tool that can read Body (B) codes will show B1447. Visually, a red OnStar LED is the definitive indicator. Given the high failure rate, it is the default diagnosis.
   Typical fix: Replace the OnStar backup battery. 🎬 Watch: Step-by-step guide to replacing the Chevy SS backup battery. In the Chevy SS, the OnStar module (VCIM) is located in the trunk, on the driver's side, behind the carpeted liner. The battery is attached to this module.
   Est. part cost: $40-$70

Rare But Worth Checking

• Improper Service Procedure: Disconnecting the main vehicle battery or the OnStar module's power while the ignition is on or Retained Accessory Power (RAP) is active can force the backup battery to activate. Since it's not rechargeable, this one-time activation will permanently drain it, requiring replacement. This is explicitly warned against in GM Technical Service Bulletin #PIC4541F.
• Wiring or Connector Issue: While rare, a damaged wire or loose connector between the backup battery and the VCIM could cause an open circuit and trigger the code. This is unlikely unless the area has been recently serviced or damaged. A diagnostic test involves checking for 15.5 volts or greater between the battery backup supply voltage circuit (Pin 14 on connector X1) and ground.

Diagnosis Steps

1. Confirm the primary symptom: a solid red light on the OnStar indicator.
2. Use an OBD-II scanner capable of reading Body (B) codes to confirm B1447 is present. A professional scanner may show a sub-code like '04' for Open Circuit.
3. Turn the vehicle ignition completely OFF. Open the driver's door to cancel Retained Accessory Power (RAP). Wait a few minutes to ensure all modules have powered down. This is a critical step to prevent draining the new battery upon installation, as per TSB PIC4541F and other GM service bulletins.
4. Open the trunk. Remove the floor covering. On the driver's side, unscrew the cargo net hooks and remove any plastic trim clips holding the side carpet liner in place. A trim removal tool is recommended.
🎬 See this walkthrough for accessing the trunk components and battery.
5. Peel back the driver's side trunk liner to expose the silver OnStar/VCIM module mounted to the chassis.
6. The backup battery is a small black box attached to the VCIM bracket. Disconnect the electrical connector from the old battery and unclip it from its mount.
7. Connect the new battery and secure it in place. Reconnect the electrical plug.
8. Reassemble the trunk liner, trim, and floor covering.
9. Clear the DTC with the scan tool. The code should not return, and the OnStar light should turn green after a short initialization period. This may require a key cycle or a short drive.

Parts You'll Likely Need

• OnStar Backup Battery (OEM #42454411) — This is the direct cause of the code. It is a non-rechargeable battery that fails with age. Part number 42454411 is cited for this application, though other GM numbers may exist.
  Trusted brands: ACDelco, GM Genuine Parts
  OEM price range: $40-$70
  Aftermarket price range: $25-$50

Related Codes That Often Appear With This One

• B1446 — B1446 indicates the backup battery's voltage is low, while B1447 indicates a complete open circuit. Both codes point to a failed backup battery and are often mentioned together in GM service documents like TSB PIC4541F.

Technical Service Bulletins (TSBs) & Recalls

• PIC4541F: Provides a diagnostic tip for OnStar back-up battery failure (DTC B1446 or B1447) and warns against improper service procedures that can drain the battery. This TSB applies to dozens of GM models from 2006-2017, including the Chevy SS.

Platform-Specific Known Issues

• A Technical Service Bulletin (TSB), #PIC4541F, was issued for this exact problem across a wide range of GM vehicles, including the 2014-2017 SS. It warns technicians to never disconnect the main battery or OnStar fuse unless the ignition is fully off and Retained Accessory Power (RAP) has timed out, as doing so can permanently discharge the backup battery.
• Owners on ssforums.com and Reddit confirm the repair is simple, with the VCIM module easily accessible in the driver's side of the trunk, behind the liner.

Mechanic-Grade Diagnostic Values

• Voltage between the backup battery supply voltage circuit and ground — expected: 15.5 volts or greater. Failure: A reading less than 15.5 volts indicates a fault in the circuit or a failed backup battery.

Hidden / Shadow Codes Worth Checking

• B1447 04: Backup Power Source Open Circuit. This is the most common variant and directly indicates the module sees no voltage from the battery, which is the classic symptom of an internally failed battery. (see via A professional scan tool like the GM GDS2/Tech2 is required to see symptom byte details.)
• B1447 07: Backup Power Source Component Protection Timeout Voltage Above Threshold. This less common variant can indicate a short to voltage in the wiring harness between the battery and the module. (see via A professional scan tool like the GM GDS2/Tech2 is required to see symptom byte details.)

Scan Tool Commands That Help

• GDS2/Tech2 or equivalent: Clear DTCs — After replacing the backup battery, the stored B1447 code must be cleared from the Telematics Communication Interface Control Module (TCICM/VCIM) to extinguish the red OnStar light and restore normal system function.

Wiring & Ground Locations

• VCIM Connector X1, Pin 14 — On the main harness connector (X1) at the OnStar module (VCIM), located in the driver's side of the trunk behind the liner.. This is the specific pin for the 'battery backup supply voltage circuit'. A technician would test for voltage between this pin and a chassis ground to determine if a fault lies in the wiring harness or the battery itself.
• VCIM Ground Circuit — The ground for the module is accomplished through dedicated circuits in the body wiring harness that terminate at chassis ground points. While a specific ground point (e.g., G-series number) for the SS's trunk was not found, checking the main ground connections in the trunk area is a valid step if a wiring issue is suspected.. A poor ground connection for the VCIM could potentially cause erratic behavior or incorrect fault codes, although it is a very rare cause for B1447 compared to battery failure.