C1110 on 2014-2019 Toyota Highlander Hybrid: "Braking Power Low" Causes and Fixes

What's Unique About the 2014-2019 Toyota Highlander Hybrid

The Highlander Hybrid's complex, electronically controlled braking system is highly sensitive to system voltage. Unlike many conventional vehicles where an ABS code points directly to a component failure, the Highlander's system often displays brake-related warnings as a secondary symptom of a failing 12V battery. Owners on forums like Reddit and ToyotaNation frequently report that a simple battery replacement resolves the C1110 code and the associated "Braking Power Low" warning, avoiding an expensive and unnecessary trip to the mechanic for brake system diagnosis.

Symptoms You May Notice

• "Braking Power Low" message on the dashboard
• ABS warning light illuminated
• Brake system warning light illuminated
• Vehicle may not start or 'power on'
• Multiple other warning lights may appear simultaneously, such as "Check AWD System" or "Check Hybrid System"
• Dim interior lights
• Audible clicking noises when trying to start the vehicle

Most Likely Causes

1. Weak or Failing 12-Volt Auxiliary Battery 🔴 High Probability → Shop Vehicle Battery The brake control module is highly sensitive to voltage drops, a common occurrence when trying to start the vehicle with an aging 12V battery. These batteries typically last only 2-4 years.
   How to confirm: Test the 12V battery with a multimeter or a load tester. 🎬 Watch: How to test your battery with a digital tester A healthy battery should be ~12.6V at rest. During startup, the voltage should not drop below 10.5 volts. Many auto parts stores will test the battery for free. A new battery that repeatedly dies suggests a parasitic drain.
   Typical fix: Replace the 12-volt auxiliary battery. It is a specialty vented AGM battery located in the rear cargo area on the driver's side. Aftermarket Group 35 AGM batteries can be adapted, but require care with the vent tube.
   Est. part cost: $250 - $450
2. Faulty ABS Actuator / Control Module ⚪ Low Probability While less common than the battery issue, the complex ABS actuator assembly can fail internally over time, sometimes from a small internal brake fluid leak. This is the component the C1110 code technically points to.
   How to confirm: If a new, fully charged battery does not resolve the code, a professional diagnostic scan tool (like Toyota's Techstream) is needed to communicate directly with the ABS module and run internal tests. Resistance across the actuator's valve solenoid coil terminals should be between 4 and 8 ohms.
   Typical fix: Replace the ABS actuator assembly. This part is extremely expensive and requires specialized procedures, including bleeding the brake system using Techstream software, and may require 🎬 Watch: How to replace the hybrid brake actuator programming to the vehicle.
   Est. part cost: $1200 - $3000+

Rare But Worth Checking

• Corroded Wheel Speed Sensors or Wiring: → Shop ABS Wheel Speed Sensor In some cases, general ABS faults from corroded sensors can trigger a cascade of codes. One owner of a 2015 Highlander with 11 ABS codes found that cleaning corrosion from all four wheel speed sensors resolved the issue.
• Faulty Brake Booster or Vacuum Pump: → Shop Power Brake Booster Though more commonly associated with non-hybrid models, a failure in the brake booster or its vacuum supply can also trigger a 'Braking Power Low' warning and may set various DTCs. A recall was issued for the vacuum pump on some 2018 Highlanders.
• Parasitic Electrical Drain: In a case documented on Reddit, a user replaced the battery to fix the "Braking Power Low" warning, only to have the new battery die again within months. This indicates a potential parasitic drain from another module or component is slowly killing the battery, causing the voltage-sensitive brake system to report a fault.

Diagnosis Steps

1. Check for the "Braking Power Low" message on the dashboard.
2. DO NOT attempt to drive the vehicle. Have it towed.
3. First, fully test the 12-volt auxiliary battery. It is located behind a trim panel in the rear cargo area on the driver's side.
4. Use a digital multimeter to check the static voltage (should be ~12.6V). More importantly, perform a load test to see how the voltage holds during a startup attempt. It should not drop below 10.5V.
5. If the battery is more than 3-4 years old or fails the load test, replace it. This is the most likely fix.
6. After installing a new battery, clear the trouble codes and see if C1110 returns. Note that some systems may need re-initialization after battery disconnection, but owners report most settings are retained.
7. If the code returns with a new, fully charged battery, the issue is more complex.
8. Visually inspect the brake fluid level and check for any obvious leaks around the master cylinder and brake lines.
9. At this point, professional diagnosis is required. A technician will use a Toyota-specific scan tool (Techstream) to check for other related codes (like C1391, C1252, etc.) and test the functionality of the ABS actuator, brake booster, and wheel speed sensors.
10. Using an ohmmeter, a technician may test the resistance across the ABS actuator's valve solenoid coil terminals. A reading outside the 4-8 ohm range indicates a faulty actuator.
11. Based on the advanced diagnostics, the fault will be isolated to the ABS module or another component in the braking system.

Parts You'll Likely Need

• 12-Volt Auxiliary Battery (AGM Type) (OEM #28800-31293) — This is the most common cause of a false C1110 code and 'Braking Power Low' warning on this vehicle. It is a specialty battery due to its location inside the cabin requiring a vent tube.
  Trusted brands: Toyota (Panasonic), Deka Intimidator, Optima YellowTop (with modifications)
  OEM price range: $350-$450
  Aftermarket price range: $250-$350
• ABS Actuator Assembly (OEM #44050-0E110 (Superseded by 44050-48320)) — If the 12V battery is not the cause, the ABS module itself has likely failed, which is what the code technically indicates.
  Trusted brands: Toyota (OEM)
  OEM price range: $1300 - $2500+
  Aftermarket price range: Not commonly available; rebuilding services may exist for $400-$800. Used units are available for ~$650.

Related Codes That Often Appear With This One

• C1431 — A user on Reddit reported a C1431 (Pedal Force Switch ON Stuck) code appeared alongside the 'Braking Power Low' message, indicating that various brake system faults can trigger the same dashboard warning.
• C1391, C1252, C1256, C1253 — These codes relate to accumulator leak and pump motor issues within the brake actuator assembly. A draft TSB for 2017-2019 Highlander Hybrids indicates these codes point to an internal brake fluid leak in the actuator, requiring replacement. They act as clarifying codes to the general C1110 controller failure.

Technical Service Bulletins (TSBs) & Recalls

• { "id": "T-SB-0072-18 Rev1", "title": "Front Brake Vibration", "relevance": "Addresses a common issue of front brake vibration or shudder during light braking, often mistaken for warped rotors. The fix involves replacing front pads and rotors with updated parts. While not directly related to C1110, it's a notable brake system issue for this platform." }
• { "id": "Draft TSB for 2017-2019 Highlander HV", "title": "ABS Brake Warning Lights On", "relevance": "A draft TSB indicates that codes C1391, C1252, C1256, and/or C1253, along with brake warning lights, may be caused by a small internal fluid leak in the brake actuator, requiring replacement of the actuator (P/N 44050-48320). This is a likely root cause if the battery is not at fault." }

Platform-Specific Known Issues

• The extreme sensitivity of the brake control module to low voltage is a well-documented quirk of this platform among owners, frequently leading to a misdiagnosis of a major brake failure when only a new battery is needed.
• The 12V auxiliary battery is located in the rear cargo area, not under the hood. It is a vented AGM type battery that is not always stocked at standard auto parts stores.
• Owners report a short lifespan for the 12V battery, often requiring replacement every 2.5 to 3 years.

Mechanic-Grade Diagnostic Values

• ABS Valve Solenoid Coil Resistance — expected: 4 - 8 Ohms. Failure: A resistance reading below 4 ohms or above 8 ohms suggests an internal fault in the ABS actuator assembly.
• ABS Module Power/Ground Voltage Drop (Load Test) — expected: < 0.5V drop from battery voltage. Failure: A voltage drop greater than 0.5V when the circuit is under load (e.g., tested with a headlamp bulb) indicates high resistance in the power or ground wiring, which can trigger false codes.

Scan Tool Commands That Help

• Toyota Techstream: Air Bleeding — This is a mandatory utility function after replacing the ABS actuator or opening any brake lines. It runs a specific, automated sequence to cycle the internal pump and solenoids to purge all air from the complex hybrid braking system. Manual bleeding is insufficient.
• Toyota Techstream: Zero Down — This utility is used before servicing the brake system to safely depressurize the high-pressure accumulator, returning fluid to the reservoir.
• Toyota Techstream: Active Test: ABS Pump Motor — Allows a technician to command the ABS pump motor on and off directly. This helps verify if the motor itself is functional and receiving the command, isolating a motor failure from a control module or wiring issue.

Real Owner Repair Stories

• YouTube channel 'Tom Bates' (2008 Toyota Highlander Hybrid (similar system to 2014-2019 models)) — All brake warning lights on, hard brake pedal, and an audible beeping noise.
  ❌ Tried (didn't work) Initially replaced only the electric motor on the ABS actuator assembly. After bleeding the brakes, the warning lights returned.
  ✅ What actually fixed it Replaced the entire ABS actuator assembly with a used unit. The repair required using Toyota's Techstream software and a specific cable to properly bleed the electronically controlled brake system, as the rear brakes cannot be bled manually.

OEM Part Supersession History

• 44050-0E110 → 44050-48320 — The reason for supersession is not officially documented in public sources, but it typically involves internal improvements for reliability or manufacturing process updates.
  Heads up: The new part number 44050-48320 is the correct replacement for the entire 2014-2019 Highlander Hybrid generation.

Model Year Variations Within This Range

• From Aug. 2016 Production: A wiring diagram indicates that some wiring related to the ABS system was changed starting from August 2016 production. This could affect pinouts and wire colors during diagnosis.
• 2017-2019: Models from 2017 onward feature LED brake lights, whereas 2014-2016 models use conventional bulbs. This is unlikely to be related to code C1110 but is a known electrical system difference.

Diagnostic Flowchart

Other Known Issues on This Vehicle

Issues unrelated to this code that are worth knowing about as an owner of this generation:

• Transmission Hesitation/Lurching (8-speed) 🟠 Medium — Common on 2017-2019 models with the 8-speed automatic transmission. Can occur at low mileage. (Ref: Software updates may be available, but some owners report persistent issues.)
• Front Brake Vibration / Shudder 🟡 Low — Common across the generation, especially during light braking at highway speeds. (Ref: T-SB-0072-18)
• Faulty Fuel Pump 🔴 High — Subject to a major recall affecting many Toyota/Lexus models. Can cause engine stalling. (Ref: NHTSA Campaign 20V012000)
• Infotainment System Freezing/Lagging 🟡 Low — Frequently reported by owners. Issues include black screens, freezing, and Bluetooth connectivity problems. (Ref: Software updates from the dealer may resolve some issues.)
• Moldy Smell from A/C Vents 🟡 Low — Caused by poor drainage design in the evaporator box, allowing water to stagnate. (Ref: No official fix, requires periodic cleaning of the evaporator case.)
• Power Tailgate Malfunction 🟡 Low — Owners report the power tailgate failing to open or close properly. Sometimes can be fixed by resetting the system.

Used vs. New Parts: Buying Guide for This Vehicle

When a used part is the smart pick: A used ABS actuator assembly is a reasonable choice given that a new OEM unit can cost over $1,500. Forum users and DIYers have successfully used parts from salvage yards or specialty recyclers to fix their vehicles for a fraction of the cost.

Donor-vehicle mileage cap: roughly under 100000 miles for the part to have meaningful remaining life.

What to inspect on the donor part:

• Verify the source is a low-mileage, clean-title vehicle if possible.
• Inspect the unit for physical damage or heavy corrosion.
• Crucially, ensure the seller capped all brake line ports immediately upon removal to prevent dirt and moisture contamination, which can destroy the unit.
• Ask about the seller's return policy or warranty period.

OEM-only on this vehicle (don't cheap out):

• ABS Actuator Assembly (when buying new)
• 12-Volt Auxiliary Battery (recommended for perfect fitment of the cabin vent tube)

Aftermarket brands forum-validated for this vehicle:

• For general brake maintenance (pads/rotors), owners report good results with Advics, Brembo, Bosch, and Power Stop.

Brands owners have reported issues with on this vehicle:

• No specific aftermarket brands for the ABS actuator were consistently cited as problematic; the primary choice is between new OEM and used OEM.

Real Owner Stories

Aggregated from forums and TSBs cited above. Mileages and costs reflect what owners reported in those sources.

Documented NHTSA Reports

Related OBD-II Codes

• C1391 — Often appears alongside brake warning lights due to a small internal fluid leak in the ABS brake actuator.
• C1252 — Related to brake actuator/pump malfunctions; cited in draft TSBs for 2017-2019 models regarding internal leaks.
• C1256 — Indicates low accumulator pressure, frequently occurring with C1110 when the ABS actuator assembly fails.
• C1253 — Relates to the hydro brake booster pump motor relay, often triggered by the same actuator internal faults as C1110.

Frequently Asked Questions