B1446 on 2014-2017 Chevrolet SS: OnStar Backup Battery Failure Explained

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

The 2014-2017 Chevrolet SS is based on the Australian Holden Commodore (VF) and built on the GM Zeta platform, which it shares with the 2010-2015 Camaro and 2009 Pontiac G8. It uses a standard GM OnStar system common to other vehicles of the era like the Camaro, Impala, and Buick LaCrosse. For this generation of GM vehicles, the backup battery has a finite service life, and failure after 5-7 years is a very common, predictable maintenance item. The diagnosis is straightforward, as this code almost exclusively points to the aged battery itself rather than a more complex system failure.

Diagnostic Flowchart

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

Symptoms You May Notice

• A solid or flashing red light on the OnStar buttons located on the rearview mirror or overhead console.
• A "Service OnStar System" message may appear on the Driver Information Center (DIC).
• Inability to connect to OnStar services when prompted.
• An email or notification from OnStar stating a diagnostic issue has been detected.

Most Likely Causes

1. Failed OnStar Backup Battery 🔴 High Probability → Shop Vehicle Battery The backup battery is a non-rechargeable lithium unit with a typical service life of 5-7 years. As vehicles in the 2014-2017 range are now well within or past this window, battery failure is an expected maintenance event due to age and chemical degradation.
   How to confirm: The presence of code B1446 combined with a red OnStar LED is the primary confirmation. A professional scan tool may show a symptom byte of '03' for 'Voltage Below Threshold'. The battery is not typically tested; it's replaced based on the code and the age of the vehicle. An OnStar advisor can also run a remote diagnostic to confirm the battery failure.
   Typical fix: Replace the OnStar backup battery module.
   Est. part cost: $40-$90
2. Accidental Discharge of Backup Battery 🟡 Medium Probability → Shop Vehicle Battery Per TSB #PIC4541F, if the main vehicle battery is disconnected or the OnStar fuse is pulled while the ignition is on or Retained Accessory Power (RAP) is active, the backup battery is triggered. Since it's non-rechargeable, this single activation will permanently drain it, requiring replacement. This can happen during unrelated service, like a main battery change.
   How to confirm: If the B1446 code appeared immediately after the main vehicle battery was replaced or other electrical work was performed, this is the likely cause.
   Typical fix: Replace the OnStar backup battery module.
   Est. part cost: $40-$90

Rare But Worth Checking

• Faulty OnStar Module (VCIM): → Shop Telematics Interface Module If a new, known-good backup battery does not resolve the code, the charging/monitoring circuit within the main OnStar module itself may be faulty. This is uncommon. Confirm by testing voltage at the VCIM harness connector; if the circuit tests normal, the VCIM is the likely culprit.
• Wiring Harness Damage: Damage to the wiring connecting the battery to the OnStar VCIM could cause an open circuit, but this is highly unlikely without other work being performed in the area. A quick physical check for a poorly seated black C3 connector at the VCIM is worthwhile.

Diagnosis Steps

1. Verify the trouble code B1446 is present using an OBD-II scanner capable of reading Body (B) codes. A GM-specific tool may show symptom code B1446 03.
2. Confirm the primary symptom: a red LED light on the OnStar buttons.
3. Turn the ignition completely OFF. Open and then close the driver's door to cancel Retained Accessory Power (RAP). Wait a few minutes for all modules to power down. This is a critical step to prevent permanently discharging the new battery upon installation, as noted in TSB #PIC4541F.
4. Locate the OnStar module (VCIM). In the Chevrolet SS and the similar 2014-2015 Camaro, it is found behind the glove compartment.
5. Open the glove compartment, press in on the sides to release the stops, and let it swing down completely.
6. Visually identify the VCIM (typically a silver metal box) and the smaller black battery module attached to it or nearby.
7. Carefully disconnect the electrical connector from the backup battery.
8. Remove the old battery module from its mounting bracket.
9. Install the new backup battery, ensuring its connector is fully seated.
10. Reassemble the glove compartment and any trim.
11. Start the vehicle. The code should clear on its own, and the OnStar LED should turn green after a few moments. If it remains, use a scanner to manually clear the code and re-check. A history code may remain but will clear after about 50 malfunction-free ignition cycles.

Parts You'll Likely Need

• OnStar Backup Battery (OEM #23117460) — This is the component that fails due to age, triggering code B1446. It is a non-rechargeable lithium battery that must be replaced.
  Trusted brands: ACDelco, Genuine GM
  OEM price range: $60-$90
  Aftermarket price range: $40-$70

Related Codes That Often Appear With This One

• B1447 — This code, for 'Backup Power Source Open Circuit', is often set along with B1446. Both point to a failure of the OnStar backup battery system, as noted in GM Technical Service Bulletin #PIC4541F.
• U0198 — This code means 'Lost Communication with Telematic Control Module'. If the entire OnStar module fails, not just its battery, this code may appear alongside the battery-specific codes.

Technical Service Bulletins (TSBs) & Recalls

• PIC4541F: Provides diagnostic tips for OnStar back-up battery failure, which causes DTC B1446 or B1447 and a red OnStar LED. It contains critical warnings about proper procedure when disconnecting power, as activating the backup battery even once will permanently drain it.

Platform-Specific Known Issues

• GM Technical Service Bulletin #PIC4541F: This TSB directly addresses codes B1446 and B1447. It warns technicians to never disconnect the main vehicle battery or OnStar fuse while the ignition is on or Retained Accessory Power (RAP) is active. Doing so can permanently discharge the backup battery, requiring its replacement. This is a critical procedural note for both DIYers and professionals.
• Owner Experience: Main Battery Longevity: → Shop Vehicle Battery In a discussion on the r/ChevySS subreddit, owners of 2014 and 2015 models noted their original main vehicle batteries lasting over 7-9 years. While this refers to the main battery, it provides context that vehicles of this age are at the point where all original batteries, including the OnStar backup unit, are reaching their expected end-of-life.

Mechanic-Grade Diagnostic Values

• Backup Battery Voltage at VCIM Connector X1 — expected: Greater than 12.3 V between terminal 14 (supply voltage) and terminal 13 (low reference).. Failure: A voltage reading below the specified range indicates a failed backup battery or a wiring circuit issue.
• DTC Run Condition - Main System Voltage — expected: 9.5V - 15.5V. Failure: If the main vehicle voltage is outside this range, the VCIM may not run the self-test for the backup battery, and other electrical DTCs will likely be present.

Hidden / Shadow Codes Worth Checking

• B1446 03: This is a symptom byte that specifies 'Replace Backup Power Source Voltage Below Threshold'. It directly confirms the reason for the B1446 code is a low voltage reading from the battery. (see via GM GDS2/MDI or an equivalent professional-grade scan tool capable of reading manufacturer-specific symptom bytes.)

Scan Tool Commands That Help

• GDS2: Read DTC Information / Symptom Byte — Use this to confirm the specific fault. Seeing 'B1446 03' provides maximum confidence that the backup battery itself has failed its voltage test and needs replacement.
• GDS2: Message Monitor — If a parasitic drain on the main vehicle battery is suspected after fixing the B1446 code, or if the VCIM is behaving erratically. This function can identify if the VCIM is remaining 'awake' when the vehicle is off, which could point to an internal module fault.

Wiring & Ground Locations

• VCIM Connector X1, Pins 13 & 14 — On the main Vehicle Communication Interface Module (VCIM) located behind the glove compartment.. These are the specific terminals for the backup battery's low reference (Pin 13) and supply voltage (Pin 14) circuits. A technician can perform a definitive voltage test here to distinguish between a failed battery and a wiring problem.
• VCIM Ground — The VCIM grounds to the chassis or a dedicated instrument panel support stud behind the right side of the dashboard.. While a bad ground is a rare cause for this specific code, a poor ground connection can cause a variety of unpredictable electronic issues. Verifying the ground is tight and clean is a good practice if other diagnostics are inconclusive.

OEM Part Supersession History

• 19118855 → 23117460 — Part has been updated or revised by the manufacturer over time.