Why Your Honda Key Fob Isn’t Working After Replacing the Battery
You went through the trouble of properly replacing the small battery in your Honda smart key fob, but it still won’t work to unlock your doors or start your engine. Now what? Don’t worry – with some targeted troubleshooting, you can get to the bottom of why replacing the battery didn’t restore function and get your keyless entry working again.
Potential Causes
There are a few reasons why changing the battery in a Honda key fob may not resolve issues:
- Incorrect Battery Replacement – If the battery was put in backward, upside down, or is the wrong voltage/size, it won’t power the key fob correctly. This is the most common mistake people make.
- Faulty New Battery – Unfortunately brand new batteries sometimes arrive drained or defective right out of the package. Estimates indicate that 1 out of 100 new batteries have problems.
- Damaged Key Fob – Over time, wear and tear can damage the key fob buttons, housing, or internal components and electronics. Dropping or getting moisture inside can impact operation.
Step-by-Step Battery Replacement Troubleshooting
Before exploring more complicated issues, double-check proper battery installation:
Accessing the Housing
Honda key fob housings typically snap open via a small seam/button on the side or bottom. Gently pry at the edge with your fingernail or use a small flathead screwdriver. Take care not to damage the plastic housing. Roughening the seam edge can impact waterproofing.
Removing the Old Battery
Once inside the housing, carefully note the +/- orientation of old battery and match it when inserting the new one. Gently slide it out to remove using your finger or a non-metal tool. Do not use metal tools as they can harm the battery or internal electronics.
Inserting an Identical New Battery
Confirm your new replacement CR2032 lithium coin cell battery matches the original model in size (32 mm diameter x 3.2 mm height), voltage (3V) and polarity position. Do not attempt substitutions or non-CR2032 batteries.
Check Proper Polarity Positioning
Verify that the positive (+) and negative (-) terminals on the new battery match the corresponding symbols molded into the inside of the key fob housing. Incorrect orientation will prevent operation. Insert the new battery carefully without twisting to maintain the correct polarity position.
[Diagram showing CR2032 Battery polarity position in key fob housing]
Close Up Housing
Re-seal the two key fob housing halves properly by snapping them back together so they seal tightly. Check seam edges to ensure flush alignment. Twist/wiggle testing ensures a water-tight closure to maintain reliability in wet conditions.
Other Troubleshooting Tips
If you’ve eliminated battery replacement mistakes but still no luck unlocking or starting the vehicle, try these additional steps:
- Test a second new CR2032 battery in case the first replacement was faulty from the manufacturer
- Visually inspect for damage/wear on housing seams, buttons, and internal switch contacts
- Attempt to re-synchronize/reprogram the key fob with the vehicle immobilizer security system
- Have a professional locksmith diagnose potential electrical or computer programming issues
"After replacing the battery twice with no success, I had my Honda dealer reset the key fob programming. Finally got it working again after that simple re-sync fix!" - Carlos R.
In some cases, if the key fob PCB internal circuit board is too damaged from water or drop damage, the device may need professional repair or replacement. Your Honda dealer can troubleshoot issues and configure/cut replacement key fob to properly pair with the vehicle computer.
When to Seek Replacement
Changing batteries and minor DIY fixes can save money short term. But continuing to replace CR2032 coin cell batteries every 6-12 months hoping issues resolve themselves long-term often ends up more wasteful.
If you’ve rigorously tried the troubleshooting tips above with no lasting fix, it is likely time to seek key fob repair or replacement. Your Honda dealer or good mobile locksmith has the technical knowledge and software/hardware tools to properly diagnose deeper electrical-computer issues causing failure and restore full smart keyless entry functionality.
Preventing Future Key Fob Problems
Follow this basic maintenance to maximize key fob longevity 5-10 years and minimize problematic loss of battery power at inopportune times:
- Keep the key fob dry and avoid temperature extremes in storage
- Wipe down with isopropyl alcohol if it gets wet
- Change the CR2032 battery proactively every 1-2 years
- Use a protective silicone case or sleeve
- Have spare key fobs programmed for backup
Following the battery change and troubleshooting tips above resolves functionality problems for most Honda owners getting the dreaded key fob failure. But If all else fails, don’t keep wasting batteries hoping the problem resolves itself. Seek professional help to get your keyless entry reliably unlocking and starting your vehicle again.