Checking the Cradle Signal

Checking the cradle signal

Troubleshooting information
The phone module (PHM) decides if the call is to be connected via handsfree or the handset based on the cradle signal. When the handset is placed in its holder, all voice calls are routed via handsfree. The handset is activated when it is removed from the holder. The cradle signal to the phone module (PHM) is controlled by a magneto switch located in the handset. The switch is closed by a permanent magnet located in the holder. The magnet on XC90 is embedded in the plastic holder. When the handset is placed in the holder, the cradle signal to the phone module (PHM) is 0 V, if the handset is used the signal is 5 V.
The handsfree will not work if there is no signal from the cradle. If there are intermittent malfunctions, calls may be disconnected when handsfree is in use.
Causes of lost function may be:
- The permanent magnet in the holder demagnetized.
- Defective magneto switch in the handset.

Continue - Checking the magnet and switch

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Checking the magnet and switch




- Ignition on.
Check the function of the cradle by measuring the signal at the handset connector. Take readings with the handset in and removed from the holder.

Checking the permanent magnet
If the correct cradle signal value is not obtained when the handset is on the cradle, check the cradle function as follows:
- Lift off the handset
- Run a metal object over the magnet (paper clip or similar), see illustration.

Checking the switch
Check the switch in the handset using a magnet. Hold the magnet in the marked area in the illustration. Check that the cradle signal changes. Also check that the switch is working (closes) when the magnet is a couple of centimeters from the handset.
Remedy as necessary.

Other information:
- Connecting the breakout box Connecting the Breakout Box, Phone Module (PHM)
- Signal description Signal Specification, Phone Module (PHM)
- Handset, replacing Handset, Replacing













Was a malfunction detected?

Yes - FAULT FOUND

No - No Fault Found

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