Having trouble with your Honda’s smart entry system? That warning light with a key and exclamation mark can be frustrating when it appears on your dashboard. Whether you’re seeing “Smart Entry System Problem,” “Keyless Access System Problem,” or struggling with door locks that won’t respond, this guide covers everything from quick DIY fixes to dealer-level solutions that could save you hundreds.
Most Common Smart Entry System Problems in Honda Vehicles
Honda’s smart entry system lets you unlock doors and start the engine while keeping your key fob in your pocket or bag. When something goes wrong, you’ll typically see one of these warnings:
- A yellow key with exclamation point icon
- “Smart Entry System Problem” message
- “Keyless Access System Problem” message
- “Keyless Start System Error” message
These warnings appear when there’s a communication breakdown between your key fob and the vehicle. The system has three main components:
- Low-power antennas in door handles, trunk, and cabin
- Keyless Access Control Unit (computer behind glove box)
- ENGINE START/STOP push-button switch
When any part loses communication with your key fob, convenience features like walk-away locking, remote start, or even engine starting may stop working.
Check Your Key Fob Battery First
The most common and easiest-to-fix problem is a weak key fob battery. About 40% of smart entry system problems are resolved with a simple battery replacement.
Here’s how to replace it:
- Slide the release tab and pull out the metal key
- Use the key or a coin to pry the fob case apart
- Note the battery position (+ side typically faces down)
- Remove the old battery and insert a fresh CR2032 or CR2025 coin cell
- Snap the case closed and test
A new battery costs about $3 and takes just minutes to replace. Your warning light should disappear once you start the car with the fresh battery.
Electronic Interference Issues
Your smart key uses radio frequencies that can be disrupted by other devices. Common interference sources include:
- Smartphones (especially when charging)
- Other key fobs
- Metal cases or RFID-blocking wallets
- Electronic devices with wireless charging
Try keeping your fob at least 4 inches away from your phone and other electronic devices. If the warning appears only occasionally, interference is likely the culprit.
Simple System Reset Procedures
Before taking your Honda to the dealer, try these reset procedures:
Basic Reset
- Turn the ignition OFF
- Exit the vehicle with your key fob
- Lock all doors using the fob
- Wait 30 seconds
- Unlock and retry
Advanced Reset
If the basic reset doesn’t work, try disconnecting your car’s 12V battery:
- Turn off all electrical accessories
- Disconnect the negative battery terminal
- Wait 10-15 minutes
- Reconnect the battery
- Start the engine and check if the warning is gone
This temporary fix often clears random glitches in the system’s memory.
Check These Fuses
A blown fuse can disable your smart entry system. For most Honda models, check:
- Interior fuse box (under dashboard): Look for fuse #23 labeled “SMART” (10A)
- Also check fuse #12 labeled “IG1 P/Start” (7.5A)
Many owners on forums report that replacing these fuses solved their problems immediately.
Low Car Battery Voltage
Your Honda’s smart entry system needs proper voltage to function. If your car battery is weak (below 12.4V), it can trigger the smart entry warning.
Signs your car battery might be the issue:
- Slow cranking when starting
- Dimming headlights
- Multiple electrical issues, not just smart entry
- Warning appears after the car sits unused for days
Test your battery voltage or have it checked at an auto parts store for free. Battery issues are particularly common in cold weather and with vehicles that make mostly short trips.
The ENGINE START/STOP Button Problem
A common issue on 2015-2017 Honda Fit and 2016-2017 Pilot/Ridgeline models is a faulty push-button starter switch. Symptoms include:
- Having to press the start button multiple times
- Engine cranking longer than normal
- “Keyless Start System Error” message
- Diagnostic trouble code B12C5
Good news: Honda extended warranty coverage for this specific issue to 9 years/125,000 miles on affected models. The switch costs about $140 plus labor if you’re out of warranty.
For DIY repair attempts, some owners have successfully:
- Removed the center trim panel
- Unplugged the switch connector
- Released the four plastic latches holding the switch
- Cleaned the copper contacts with electronic contact cleaner
- Reassembled everything
This cleaning procedure may temporarily fix intermittent starts, but replacement is the permanent solution.
Door Handle Antenna Issues
If you notice the smart entry system works inconsistently with certain doors, the problem might be the antenna in the door handle:
- Driver’s door unlocks only sometimes
- Passenger doors work but not driver’s door
- Trunk works but doors don’t
Each door handle contains an antenna that communicates with your key fob. These can be damaged by:
- Impact (door dings, parking lot bumps)
- Water intrusion
- Wire harness pinching
Replacement door handle sensors cost about $90 each plus labor. This repair is less common but reported by several Civic owners.
Keyless Access Control Unit Failures
The most expensive (but thankfully less common) issue is a failed Keyless Access Control Unit. This small computer is typically located behind the glove box or center console and controls all smart entry functions.
Symptoms of a bad control unit:
- Walk-away auto lock doesn’t work
- Multiple key-related warning messages
- System works intermittently, especially in cold weather
- Diagnostic codes B1175 or B12D5
This repair costs around $200 for the part plus programming labor. Some models have specific warranty extensions:
| Model | Years | Extended Coverage | TSB Number |
|---|---|---|---|
| Ridgeline | 2017-2019 | 5 years/unlimited miles | 21-055 |
| Accord V6 | 2013 | Standard warranty | 13-038 |
If your vehicle isn’t covered by a service bulletin, you can save money by purchasing the OEM unit online (~$190) and paying an independent Honda specialist shop for installation and programming.
Aftermarket Modification Problems
If your smart entry issues began after installing aftermarket equipment, there might be electrical interference or a wiring problem:
- LED headlight kits
- Subwoofer amplifiers
- Dash cams with hardwire kits
- Fog light wiring harnesses
Several Honda forums report that certain aftermarket installations can create RF noise that affects the smart entry system. Try disconnecting your most recent modification to see if the problem resolves.
Model-Specific Extended Warranty Coverage
Honda has issued several Technical Service Bulletins (TSBs) extending warranty coverage for smart entry problems:
| Bulletin | Models/Years | Problem | Coverage | Repair |
|---|---|---|---|---|
| 20-098 | Fit EX/EX-L 2015-17 | “Keyless Start Error” | 9 yrs/125K miles | Replace START button |
| 20-117 | Pilot 2016-17, Ridgeline 2017 | Same as above | 9 yrs/125K miles | Replace START button |
| 21-055 | Ridgeline 2017-19 | Alarm sounds, keyless faults | 5 yrs/unlimited | Replace control unit |
Even if your vehicle isn’t specifically listed, dealers can often submit a “goodwill” warranty adjustment if your mileage is reasonable and you have maintenance records. Always ask about this possibility.
Preventive Maintenance Tips
To avoid future smart entry problems:
- Replace key fob batteries every 2 years or when range drops
- Keep fobs away from electronic devices and metallic objects
- Clean door handle sensors with isopropyl alcohol during car washes
- Maintain your car’s 12V battery (keep it charged above 12.4V)
- Check for Honda software updates for your infotainment system
- Avoid routing aftermarket wiring near the smart entry components
When To Consider Professional Diagnosis
While many smart entry problems can be fixed at home, seek professional help when:
- You’ve replaced the battery, checked fuses, and reset the system without success
- Multiple warning messages appear simultaneously
- The engine won’t start at all (no crank)
- Your model has a known TSB but you need warranty coverage
- You need key fob programming after component replacement
A professional Honda diagnostic tool can read specific fault codes that pinpoint exactly which component has failed.
Costs You Can Expect
| Repair | DIY Cost | Professional Cost | Notes |
|---|---|---|---|
| Key fob battery | $3 | $15-25 | Easiest fix, try first |
| Fuse replacement | $1 | $50-75 | Check both SMART and IG1 fuses |
| START/STOP button | $140 + labor | $250-350 | Often warranty covered |
| Door handle sensor | $90 + labor | $200-300 per door | Requires trim removal |
| Control unit | $190 + programming | $500-1,000 | Most expensive repair |
Remember that diagnostic fees ($100-150) may apply at dealerships but are often waived if you proceed with repairs.
By systematically working through these solutions—from simple battery replacement to component testing—you can solve most Honda smart entry problems without breaking the bank. For the most stubborn issues, having a dealer check for applicable warranty extensions might save you hundreds on what would otherwise be an expensive repair.
