2014-2015 Infiniti Q50 Access Module Failure: The 'Key Not Detected' and Water Leak Guide
This guide covers the common causes of failure, mandatory programming requirements, and replacement costs for the Vehicle Access Control Module in your 2014-2015 Q50.
- A replacement module MUST be programmed to the vehicle by a dealer or qualified locksmith with a CONSULT-III or equivalent tool; it will not work otherwise.
- Failure is very often caused by water leaking from a clogged passenger-side sunroof drain, which drips directly onto the module. Always fix the leak before replacing the part.
- The most common symptoms are a "No I-Key Detected" warning on the dash and the engine refusing to start.
- This specific module (part number 28595-4HB0A) is for 2014-2015 Infiniti Q50 models with the 3.7L V6 engine only.
Critical Warning: Sunroof Drain Leaks Can Destroy This Module
Warning: The most common cause of failure for the Vehicle Access Control Module (BCM) in the 2014-2015 Q50 is water damage. The passenger-side sunroof drain tube can become clogged or its grommet at the firewall can fail, causing water to leak directly onto the BCM and its electrical connectors. This leads to severe corrosion, causing intermittent electrical problems that eventually lead to complete failure. Before replacing the module, it is essential to find and fix the source of the leak to prevent damage to the new part.
Symptoms of a Failing Vehicle Access Control Module
When the access module begins to fail, you'll notice problems related to the key and ignition system. Often, these symptoms start intermittently before becoming permanent.
- "No I-Key Detected" or "I-Key System Error" Message: The most common symptom is a warning on the instrument cluster stating the key cannot be found, even when it's inside the vehicle.
- Engine Will Not Start: The car may not respond when you press the push-to-start button. All other electronics might turn on, but the engine will not crank.
- Remote Key Fob Inoperable: The buttons on your key fob for locking and unlocking the doors may stop working.
- Interior Lights Malfunction: In some cases, failure can also affect the interior dome lights.
Pro Tip: Before suspecting the module, always perform these simple checks first: replace the battery in your Intelligent Key fob, and ensure your main 12V car battery is fully charged and in good health. A weak car battery can cause similar communication errors with the key system.
Known Issues, TSBs, and Recalls
Infiniti Technical Service Bulletin ITB13-052b
Infiniti issued a technical service bulletin regarding the "Intelligent Key Not Detected" symptom. It notes that radio frequency (RF) interference from aftermarket devices like phone chargers, dash cams, or alarm systems can disrupt the signal between the key and the module. Technicians are advised to rule out these sources of interference before replacing the BCM.
Recalls
As of this writing, there are no specific recalls for the Vehicle Access Control Module on the 2014-2015 Infiniti Q50. Recalls issued for this vehicle have addressed other components like the Direct Adaptive Steering system, airbags, and driveshafts.
Diagnosis and Replacement
Confirming a Bad Module
- Check for Water Damage: The module is located inside the cabin on the passenger side, behind the dashboard finisher near the firewall. Inspect the module, its connectors, and the surrounding carpet for any signs of moisture, corrosion, or water stains. Green or white crust on the electrical pins is a clear sign of water intrusion.
- Scan for Codes: A professional scan tool that can communicate with the BCM is needed. Generic OBD-II readers may not see the necessary codes. Look for codes related to the immobilizer system (NATS) or communication errors with the key.
- Rule Out Other Causes: A no-start condition can also be caused by a bad starter motor or a faulty brake pedal switch, which must be pressed for the car to start.
Important: This module is specific to 2014-2015 Infiniti Q50 models equipped with the 3.7L V6 engine. Ensure you are purchasing the correct part for your vehicle's specific configuration.
Programming is Mandatory
You cannot simply swap this module and expect it to work. A replacement Vehicle Access Control Module—whether it is new or used—must be professionally programmed to your vehicle. The programming process syncs the module to your car's VIN, its specific options, and your existing Intelligent Keys. This is a critical part of the vehicle's anti-theft system.
- Who can program it? An Infiniti dealership is the most common option, as they have the required CONSULT-III plus diagnostic tool. However, many well-equipped independent auto repair shops and professional automotive locksmiths also have tools (such as Autel programmers) capable of performing this service.
- Can I do it myself? No. Due to the need for proprietary software and tools, this is not a feasible DIY job for the home mechanic.
- Cloning as an Option: Some specialized electronics repair services can "clone" the data from your original (but damaged) module onto a donor used module. This can sometimes be a workaround to avoid the need for key reprogramming, but requires sending both modules to a specialist.
Buying a Used Vehicle Access Control Module
A used OEM module is a great way to save money, as the hardware is identical to what the dealer sells. However, you must be careful to ensure you get a good, compatible part.
- Verify the Part Number: The primary OEM part number for this module is 28595-4HB0A. Always match this number exactly. While there are superseding numbers, matching the original ensures compatibility.
- Inspect for Corrosion: When buying from a seller that provides photos, closely examine the electrical pins in the connectors. Do not buy any module that shows signs of green or white corrosion, as this indicates it suffered the same water damage you are trying to fix.
- Factor in Programming Costs: Remember that the price of the used module is only part of the total cost. You must still pay for professional installation and programming, which can cost several hundred dollars.
- Why Used OEM is a Good Choice: For a critical electronic component like this, a used original part is often more reliable than a new, unbranded aftermarket part. It was designed and tested by Infiniti for your specific vehicle.
Replacement Cost Comparison
The total cost can vary significantly based on the source of the part and the labor/programming fees.
| Part Source | Estimated Part Cost | Estimated Labor & Programming | Total Estimated Cost |
|---|---|---|---|
| New OEM (Dealer) | $550 - $1,000 | $250 - $500 | $800 - $1,500+ |
| Used OEM (Recycled) | $30 - $100 | $250 - $500 | $280 - $600 |
| New Aftermarket | $200 - $400 | $250 - $500 | $450 - $900 |
Note: Prices are estimates and can vary based on your location and the repair shop's labor rates. Some dealer quotes for a full replacement have been reported as high as $3,000 when connector repair is needed.
Frequently Asked Questions (FAQ)
Do I have to program a replacement Vehicle Access Control Module?
Yes, programming is absolutely mandatory. The module is tied to the vehicle's anti-theft system and must be configured to your car's VIN and keys using specialized diagnostic tools. The car will not start without this step.
Where is the Vehicle Access Control Module located on a 2014-2015 Q50?
It is located inside the vehicle, on the passenger's side. You can access it by removing the dashboard side finisher panel. It is mounted vertically near the firewall, sometimes described as being behind the glove box area.
Can a locksmith program this module instead of the dealer?
Yes, many professional automotive locksmiths have advanced programming tools that can configure a new or used BCM and program your keys to it. It is often more cost-effective than going to a dealer. Always call ahead to confirm they have the capability for your specific Infiniti model.
Will a bad access module drain my car's battery?
Yes, it is possible. A faulty module, especially one with internal shorts from water damage, can fail to shut down properly and cause a parasitic draw that drains the 12V battery when the car is off.
Technical Specifications
OEM Part Numbers: 28595-4HB0A 284B1-4HB0A 284B1-4HB0C 284B1-4HB0D 284B1-4HB0E 284B1-4HB1A 284B1-4HB1B
Controls vehicle access, keyless entry, and the Nissan Anti-Theft System (NATS). Operates on 315 MHz and 433 MHz frequencies.
We Have This Part in Stock
The information in this article is provided for general reference and educational purposes only. Vehicle specifications, procedures, and part compatibility can vary by production date, trim level, and region. Always consult your vehicle's factory service manual and verify part numbers before purchasing or performing repairs. Safety-critical components such as airbags, seat belts, and braking systems should be installed by a qualified professional.
- INFINITI Q50:
- 🛍️ Shop This Part
- Critical Warning: Sunroof Drain Leaks Can Destroy This Module
- Symptoms of a Failing Vehicle Access Control Module
- Known Issues, TSBs, and Recalls
- Infiniti Technical Service Bulletin ITB13-052b
- Recalls
- Diagnosis and Replacement
- Confirming a Bad Module
- Programming is Mandatory
- Buying a Used Vehicle Access Control Module
- Replacement Cost Comparison
- Frequently Asked Questions (FAQ)
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