There is no volume for the radio, Onstar and phone do not work in car? Radio panel lights up-Display showed that Onstar called but no sound.

The Radio and OnStar are monitored by the BCM, so removing the stock radio will have confused it. Details in the link.

https://www.google.com/search?q=2009+chevy+tahoe+ltz+disable+OnStar

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What system does it have ? Base or up level ,does it have a amp ? Do you know what a RPO code is ? Without testing no one could say for sure what the issue is . First off would need to know what system we are dealing with .
RPO Options
The entertainment system on this vehicle is configured with either a base or uplevel audio system. Both the base and uplevel audio systems contain a radio, antenna, and speakers.
The following shows the Enteratinment RPOs that are available for this vehicle:
• (UM7) AM/FM Stereo
• (U1C) AM/FM Stereo CD
• (US8) AM/FM Stereo, CD, MP3, RDS, EQ
• (US9) AM/FM Stereo, 6-Disc CD, MP3, RDS, EQ
• (UXQ4) Base Four Speaker
• (U79) Uplevel Four Speaker
• (WBM) Premium Audio
• (U2K) Digital Radio

Circuit Operation
Radio Power: The main radio power is supplied by the 10A RADIO (BATT1) fuse in the body control module (BCM). Radio switch-on power, 12 volts in ACC, RUN or RAP, is supplied by the 10A RADIO (ACC.) in the BCM.
Radio Grounds: The main radio ground provides a ground for the radio circuits. An additional braided ground strap provides a shielding radio case ground to reduce EMI noise. Both grounds are connected together inside the radio.
Radio Speaker Outputs: At zero volume, the plus (+) and minus (-) speaker outputs are both approximately 5-6 volts, measured to vehicle ground. If a plus or minus for any speaker output is shorted to ground or voltage, the radio circuitry will turn OFF all 4 speaker outputs for component protection. Above zero volume, the plus and minus change to create a voltage difference between each other, to drive the voice coil of the speaker.
Radio Park Lamp Input: The radio park lamp input allows the radio to sense when the vehicle parking lamps are ON. When the parking lamps are ON, this circuit goes to battery voltage, and the radio display back-lighting switches from full bright to the brightness level determined by the I/P illumination input.
Radio I/P Illumination Input: A pulse width modulated (PWM) voltage for instrument panel (I/P) illumination is provided to the radio I/P illumination input. The Radio uses this input to directly illuminate the radio buttons and adjust the radio display back-lighting when the park lamp input is ON.
Amplifier Power: The main amplifier power is provided by the 20A PREM AUDIO fuse in the instrument panel fuse block..
Amplifier Radio Speaker Inputs (WBM only): The radio speaker outputs, at a reduced output level for amplified systems, are the amplifier inputs. The amplifier boosts these inputs and outputs them to the vehicle speakers. Speaker plus and minus circuits from the radio change to create a voltage difference between each other. If one speaker plus or minus is open between the radio and the amplifier, the input to the amplifier is approximately half because only one of the circuits is changing. The speaker for that channel then operates at approximately only half the normal volume.
Amplifier Speaker Outputs (WBM only): At zero volume, the plus (+) and minus (-) speaker outputs are both approximately 5-6 volts, measured to vehicle ground. If a plus or minus for any speaker output is shorted to ground or voltage, the amplifier circuitry will turn OFF either the front outputs or rear outputs for component protection. Above zero volume, the plus and minus change to create a voltage difference between each other, to drive the voice coil of the speaker.
Amplifier Radio-On (WBM only): When the radio is ON, this circuit is pulled to 12 volts by the radio. The amplifier switches ON when this circuit is 12 volts and switches OFF when this signal is 0 volts.
Remote Radio Audio Signal Inputs (UE1 only): Audio output from the OnStar® communications module connects to the remote audio signal inputs of the radio. When the cellular telephone mute signal goes to 0 volts, the radio over-rides any other audio signal and uses these inputs as the source for output to the speakers.
Cellular Telephone Mute (UE1 only): The OnStar® communications module uses the cellular telephone mute signal circuit to over-ride the radio for OnStar® communication. When cellular telephone mute is not active, this circuit is held at 2 volts by the radio. When the cellular telephone mute signal is pulled to ground, the radio over-rides any other audio signal and uses the remote audio signals as the source for output to the speakers. If the radio was OFF when this circuit is pulled low, the radio will turn ON. Additionally, the radio fades the speakers to full front, adjusts the volume to an initial audible level, and sets an AutoTone designed for optimal use with OnStar®. When the mute signal is no longer pulled to ground, the radio returns to the mode it was in previously.

Hooking up a professional or factory scan tool that can read radio codes would be one of the first test's to do .
DTC B1025, B1035, B1045, or B1055 (w/out RPO WBM)
DTC B1025, B1035, B1045, or B1055 (w/ RPO WBM)
DTC B1030, B1040, B1050, or B1060 (w/ out RPO WBM)
DTC B1030, B1040, B1050, or B1060 (w/ RPO WBM)
DTC B1259
The following conditions are present for 250 ms or longer:
B1025 - B1055 01
One of the speaker positive output circuits is shorted to battery.
B1025 - B1055 02
The speaker positive output circuit is shorted to ground.
B1025 - B1055 04
The speaker positive output circuit is open.

Your best bet , take it to a qualified repair shop .

http://gmauthority.com/blog/2015/07/general-motors-recalls-50731-units-of-chevy-spark-and-sonic-over-freezing-radios/


If your radio has the onstar capability, gm has issued a recall for the issue. If not, check the fuses to see if the display fuse is different than the actual radio fuse in your owners manual. Many new, especially "touch screen radios", connected to onstar for navigation have a tendency to freeze up or not display and gm will fix it for you as they recalled over 50,000 vehicles for it.

Could be that the potentiometer is not tracking properly. If that is not it, then it is the chip that controls the volume at fault.

It could be a bad amp. Those come with a factory amp usally right behind the radio. Hopefully you can find a used one from a scrap yard. Click Here to search in your area.

This is an Internal problem in the radio. and the radio will need to be repaired Or have an aftermarket radio installed.Installing an aftermarket radio is usually the least expensive way to go unless you have onstar. than have the radio repaired since onstar works through the factory radio.

I was told by on star that if you leave the drivers door open for 90 seconds and then lock all of the doors and wait until the next day the system will reset itself. I know this sounds like smoke and mirrors but it does work. Please let me know. Hope this helps.

I had the same problem with my 04 Suburban, sound and then no sound from anything (radio, on star, door chime, etc). The dealership thought it was the radio, so they put a new radio in. A day later the same problem. It turned out to be the amplifier under the center console. Everything is working with no problem for over a year.

Depress the volume bottom or rotate the volume knob. When on a Bluetooth phone call, the speaker symbol will mute, but unmute when the call ends. Either rolling the right steering wheel scroll or the volume button on the shifter area will should unmute the radio volume.

It is a fault in the phone. The system is designed to where you can not talk on the phone while you are driving unless you are in hands free mode.