Symptom
Hands-free calling not working
The vehicle will not pair with a phone, drops the connection, or takes calls with no sound in either direction. Worth treating as more than an inconvenience: hands-free operation is what makes using a phone in a moving vehicle lawful in most jurisdictions, and the temptation created by a broken system is to pick the handset up. Let calls go to voicemail and stop the vehicle if one must be answered.
A free fix works surprisingly often: delete the pairing on both the phone and the vehicle and pair them again from scratch. A phone software update, a new handset or a disconnected battery can leave a stale pairing that fails in ways indistinguishable from a hardware fault.
After that, the usual causes are an aftermarket head unit the vehicle does not recognise, or the roof aerial the phone connection depends on.
Also described as: bluetooth not working, phone will not pair, hands free not working, cannot connect phone, no sound on calls, bluetooth keeps disconnecting, carplay not working, android auto not working, بلوتوث وصل نمیشود, هندزفری ماشین کار نمیکند, manos libres no funciona, bluetooth no conecta, no se escucha llamadas, البلوتوث لا يتصل, المكالمات لا تعمل, ما يسمعوني بالمكالمة
What this usually means
Worth treating as more than an inconvenience: hands-free operation is what makes using a phone in a moving vehicle lawful in most jurisdictions, and the temptation created by a broken system is to pick the handset up. Let calls go to voicemail and stop the vehicle if one must be answered.
A free fix works surprisingly often: delete the pairing on both the phone and the vehicle and pair them again from scratch. A phone software update, a new handset or a disconnected battery can leave a stale pairing that fails in ways indistinguishable from a hardware fault — the devices believe they know each other and the connection never completes.
Do it on both sides. Deleting only the vehicle's record leaves the phone's, and vice versa, which is why a half-done reset often appears not to help.
After that, the usual causes are an aftermarket head unit the vehicle does not recognise, or the roof aerial the phone connection depends on — several vehicles route the phone's antenna connection through the roof aerial assembly, so headlining work or roof bars affect call quality as well as navigation.
A connection that establishes but has no audio in one direction separates neatly: no sound to the caller is the microphone, which lives in the headlining or the mirror and is disturbed by the same work; no sound to the cabin is the audio path, which is the head unit or an amplifier.
And check the phone's own permissions. A phone that has not granted contact and call permissions to the vehicle connects and then fails to do anything useful, which reads exactly like a broken system.
Working through it
| What you find | Likely cause | How to confirm it | What fixes it |
|---|---|---|---|
| Will not pair, or drops the connection | A stale pairing — very common after a phone update, a new handset or a battery disconnection | Try a different phone. If that pairs, the original's record is the problem. | Delete the pairing on BOTH the phone and the vehicle, then pair from scratch. Half a reset often appears not to help. |
| Connects but the caller cannot hear you | The microphone — usually in the headlining or the mirror | Direction is the discrimination. Check whether headlining or mirror work has been done. | Repair the microphone or its lead. |
| Connects but you cannot hear the caller | The audio path — the head unit or an amplifier | Check whether music plays through the same speakers. Working audio narrows it to call routing. | Repair the head unit or amplifier, or its coding. |
| Aftermarket head unit fitted | A unit the vehicle does not recognise, or one without the correct interface | Establish what was fitted. See the infotainment entry, where this is the dominant cause on older cars. | Fit the vehicle-specific interface or restore the original unit. |
| Connects but contacts or call history are missing | Permissions on the phone rather than a vehicle fault | Check the phone's Bluetooth permissions for contacts and calls. This reads exactly like a broken system. | No vehicle repair. Grant the permissions and reconnect. |
| Poor call quality since headlining or roof work | The roof aerial assembly, which several vehicles route the phone connection through | Correlate with the work. Navigation reception is often affected at the same time. | Reconnect or renew the aerial. |
-
Will not pair, or drops the connection
- Likely cause
- A stale pairing — very common after a phone update, a new handset or a battery disconnection
- How to confirm it
- Try a different phone. If that pairs, the original's record is the problem.
- What fixes it
- Delete the pairing on BOTH the phone and the vehicle, then pair from scratch. Half a reset often appears not to help.
-
Connects but the caller cannot hear you
- Likely cause
- The microphone — usually in the headlining or the mirror
- How to confirm it
- Direction is the discrimination. Check whether headlining or mirror work has been done.
- What fixes it
- Repair the microphone or its lead.
-
Connects but you cannot hear the caller
- Likely cause
- The audio path — the head unit or an amplifier
- How to confirm it
- Check whether music plays through the same speakers. Working audio narrows it to call routing.
- What fixes it
- Repair the head unit or amplifier, or its coding.
-
Aftermarket head unit fitted
- Likely cause
- A unit the vehicle does not recognise, or one without the correct interface
- How to confirm it
- Establish what was fitted. See the infotainment entry, where this is the dominant cause on older cars.
- What fixes it
- Fit the vehicle-specific interface or restore the original unit.
-
Connects but contacts or call history are missing
- Likely cause
- Permissions on the phone rather than a vehicle fault
- How to confirm it
- Check the phone's Bluetooth permissions for contacts and calls. This reads exactly like a broken system.
- What fixes it
- No vehicle repair. Grant the permissions and reconnect.
-
Poor call quality since headlining or roof work
- Likely cause
- The roof aerial assembly, which several vehicles route the phone connection through
- How to confirm it
- Correlate with the work. Navigation reception is often affected at the same time.
- What fixes it
- Reconnect or renew the aerial.
Codes that produce this symptom (5)
Listed with the codes that most typically present this way first — the likeliest place to start.
- U0197 Lost Communication With Telephone Control Module Typical of this code Moderate
- U0498 Invalid Data Received From Telephone Control Module Typical of this code Moderate
- U0564 Invalid Data Received From Speech Recognition Module Typical of this code Low
- U0198 Lost Communication With Telematic Control Module High
- U0499 Invalid Data Received From Telematic Control Module High
Information, not instruction
CarGeek is a reference, not a service manual. Its pages are written from public sources and from what other people have found, never from a manufacturer's own service information, so they can be wrong or incomplete for your particular vehicle. Some of what they describe carries real risk: high voltage, fuel under pressure, stored energy, hot and moving parts.
Have anything you intend to act on checked by a trained person against the manufacturer's own procedure for your vehicle. Nothing here replaces that procedure.
Others with this symptom
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- The car — make, model, year and engine. The same fault behaves differently on each.
- What you measured, not only what you replaced.
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