Radio, Stereo, and Compact Disc: Description and Operation

RADIO

CIRCUIT OPERATION

Battery Voltage is provided to the radio at all times through the P wire. In addition to the anti-theft feature, this input voltage keeps the preset station memory alive. Whenever battery power to the unit is lost, the anti-theft code must be entered and the preset stations must be reprogrammed (if enabled).

When the Radio (Z111) and the ignition are turned on, the voltage signal through the WK wire to the control head "wakes up" the unit. The Radio (Z111) plays, the LCD display comes on and the control buttons illuminate. On some models, when the park lamps or headlamps are turned on, a voltage signal is sent through the RW wire to dim the LCD display and control buttons for night driving.

Radio (Z111) signals are received via a coaxial cable from the side screens and antenna amplifiers. The amplifiers filter and boost the signal from the side screen, using power supplied on WO wires, whenever the ignition switch (X274) is in position I or II.

The CD Changer (Z114) is permanently supplied with power through the P wire via the radio and a DIN cable.

The high line (NAS/JAPAN) radio has the following features: Electronically tuned AM/FM cassette radio (Z111), RH antenna amplifier (Z178) for AM/FM signals, LH antenna amplifier (Z177) for FM signals only, a subwoofer amplifier (Z176), a CD changer (Z114) a Digital Signal Processor (DSP) amplifier (Z293) and 10 speakers plus a subwoofer speaker (K146).

Subwoofer
The subwoofer amplifies frequencies between 20 and 150 Hz to give an enhanced bass sound.

Subwoofer Amplifier
The subwoofer (K146) is supplied with power and ground from the Subwoofer Amplifier (Z176) via two separate channels which consist of 4 BW/B wires. The subwoofer amplifier (Z176) is permanently switched on when the radio supplies a signal on the SB wire.

Speaker Amplifier
The DSP amplifier (Z293) is located behind the LH rear luggage compartment behind the subwoofer. The DSP amplifier (Z293) now incorporates the door amplifiers which are no longer fitted separately. Navigation information is supplied to the DSP amplifier (Z293) which outputs the information to the relevant speaker(s).

Side Screen Antenna
The antenna is printed into the rear side screen. For NAS and Japan, the element is fitted in both rear side screens. This is referred to as a diversity antenna system. Other markets have a single element in the right hand screen only. Diversity reception means that as vehicle movement results in loss of signal due to reflections from buildings (known as multipath distortion), the radio will switch to the antenna receiving the strongest signal. This results in less interference and better stereo performance.

Antenna Amplifier
Antenna amplifiers are in the LH and RH side of the luggage compartment behind trim panel.The FM and AM amplifier would be located on the RH side, and the FM only amplifier is located on the LH side.

Speakers
Trim level 1/2 - The low/midline radio is equipped with 6, 8 or 10 speakers fitted in the doors. The midrange speakers (K200, K201, K211, K212) are filtered by capacitors in the wires (K239, K240, K247, K248) and the tweeter speakers (K197, K198) filter the signals by built-in capacitors.

Trim level 3/4 - the high line radio is equipped with 10 speakers. The signals for the tweeter speakers (K197, K198) are filtered by their internal capacitors, similar to the mid/low line tweeters.