Dropped Calls

Customers may perceive dropped calls as being an HFL system fault, but most dropped calls are from cell phone and cell phone carrier issues. The HFL system does not directly handle the cell phone signal. It allows the cell phone to transmit the cell phone audio over the vehicle's audio system.

Before troubleshooting for dropped calls, confirm the cell phone settings:

• Disable Audio Answer. If Auto Answer is enabled, incoming calls are routed to voice mail.
• Disable Always Ask/Trust, Authorize Device, or similar setting, If these settings are enabled, each time the HFL system attempts to link to the phone, the phone will ask if you want to connect. If you do not allow the connection, the HFL will not operate. The phone must be set to Never Ask, Authorize Device, etc. (based on the phone manufacturer and carrier) for permission. Refer to the cell phone owner's manual for more information.
• Disable Flip Open to Answer. If this setting is enabled, the phone must remain open in the vehicle. If it is closed, the incoming calls are routed to voice mail.

Always confirm with the customer if the number of dropped calls is higher while using the HFL system as opposed to using the cell phone only. Customers often confuse problems with their phone or carrier as a problem with the HFL system. The HFL system cannot control or determine:

• Cellular connection quality.
• Signal strength.
• Cellular coverage.
• Ambient weather conditions that affect cellular signals.

When a customer complains about dropped calls, ask questions about when or where the calls are dropped, such as:

• Do you drive the same route on a regular basis?
• Does the call drop in the same location?
• Where do you keep your cell phone?
• Have you compared the number of dropped calls using the HFL versus making calls from the handset?
• Does your phone have an antenna that needs to be extended?

Many reasons for a dropped call are not related to the HFL system. Here are some causes for dropped calls:

• If the quantity of dropped calls is about the same when the customer uses the HFL system versus the handset, the issue is likely due to the cellular phone or carrier.
• If the phone is equipped with a retractable antenna, it needs to be extended to maximize signal strength.
• If a customer also notices that the calls tend to drop in the same areas, the HFL system may be operating normally, but something about the area diminishes cellular coverage to a point where the call drops.
• Hills or mountains can block or interfere with cellular signals.
• High-rise buildings, bridges, or other large structures may block or interfere with cellular signals.
• Placing the cell phone in a purse, in a metal briefcase, under the seat, in the glove box, or in the trunk can all affect signal reception.
• There are coverage gaps in the cellular service. When driving, a call is typically passed from one tower to another. If the customer drives through an area where there is a coverage gap between towers, the call drops.
• Electrical storms, heavy rain, or overcast conditions interfere with signal strength.
• The cell phone battery's state of charge can affect signal reception. A low battery may reduce the phone's ability to boost the antenna's power and function properly, especially in low signal strength areas. Some phone manufacturers trade off signal transmission and reception strength for battery life. As the battery weakens, the signal strength may also weaken. Some cell phones may operate more effectively than others in low signal strength areas, especially with a partially charged battery, and depending on whether or not the retractable antenna is fully extended (if applicable). On these models, make sure the antenna is always extended to maximize signal strength and extend battery life.