GMC 2001 Sierra 1500 Pickup Owner's Manual page 207

EJECT: Press this button to remove the tape or stop
the tape and play the radio.
CLN: If this message appears on the display, the cassette
tape player needs to be cleaned. It will still play tapes, but
you should clean it as soon as possible to prevent damage
to the tapes and player. See "Care of Your Cassette Tape
Player" in the Index. After you clean the player, press and
hold EJECT for five seconds to reset the CLN indicator.
---
The radio will display
CD Adapter Kits
It is possible to use a portable CD player adapter kit
with your cassette tape player after activating the bypass
feature on your tape player.
To activate the bypass feature, use the following steps:
1. Turn the radio on.
2. Insert the adapter into the cassette slot.
3. Within five seconds, press and hold the REV and FWD
buttons at the same time for three seconds. The tape
symbol on the display will flash, showing that the
broken tape detection feature is no longer active.
This override routine will remain active until EJECT
is pressed.
3-20
to show the indicator was reset.
AM-FM Stereo with Cassette Tape Player
and Automatic Tone Control (If Equipped)
Playing the Radio
-
PWR VOL: Press this knob to turn the system on
and off. To increase volume, turn the knob clockwise.
Turn it counterclockwise to decrease volume. The knob
is capable of being turned continuously.
RECALL: Display the time with the ignition off by
pressing this button. When the radio is playing, press
this button to recall the station frequency.