PIC6602Q Service Bulletin/Repair Instructions

Bulletin No.: PIC6602Q
Service Bulletin
Date: December, 2025
PRELIMINARY INFORMATION

Subject:

Brand:
IOK Radio Issues

Model:
Model Year:

from
VIN:

to
from
Engine:
Transmission:
to
BrightDrop
Zevo 600
2023
All
All
All
All
Chevrolet
Corvette
2024-2025
All
All
All
All
Chevrolet
Silverado

1500
2022-2026
All
All
All
All
Chevrolet
Silverado

2500
2024-2026
All
All
All
All
Chevrolet
Silverado

3500
2024-2026
All
All
All
All
Chevrolet
Suburban
2022-2024
All
All
All
All
Chevrolet
Tahoe
2022-2024
All
All
All
All
GMC
Sierra 1500
2022-2026
All
All
All
All
GMC
Sierra 2500
2024-2026
All
All
All
All
GMC
Sierra 3500
2024-2026
All
All
All
All
GMC
Yukon
2022-2024
All
All
All
All
GMC
Yukon XL
2022-2024
All
All
All
All
GMC
Hummer
2022-2025
All
All
All
All
Involved Region or Country
North America
Additional Options (RPO)
IOK

Customers may comment of:

• No audio concerns.
Condition
• Blank, Black, Freezing/Frozen, or Glitching Display screen.

• "Return to Dealer" or "Demo Mode" message on the display.

• Phone connectivity concerns
Cause
Concerns may be software, connection, or hardware.
Correction

Note: If the VIN you need a radio for is part of N252504460- Customer Satisfaction Program - Radio Replacement

and Reprogramming this PI is not applicable, please call/order as per step 1.8 below and state that the part is

required for a VIN applicable to N252504460 - Customer Satisfaction Program - Radio Replacement and Reprogramming

1. For a blank or black screen that cannot be viewed refer to PIC6540 and perform a reset on the radio to see if

display returns, continue with steps below. If display does not return, follow normal SI diagnostics.

Note: This step does not apply to screens that go blank and recover, if the vehicle comes in with this concern

proceed to step 1.2 and update the vehicle to the latest software
Copyright 2025 General Motors. All Rights Reserved.
Page 2
December, 2025
Bulletin No.: PIC6602Q
1.1 For a return to dealer or Demo Mode message displayed on the radio screen see PIT6209, if the display shows

Device is Starting and is stuck on that screen, please refer to PIC6630.

1.2 Check current software and verify the radio software is up to date per:

• 25-NA-121 for 2025 LD trucks. 2025 HD Trucks and 2022-2023 SUVs

• 25-NA-318 for 2022-2023 LD Trucks, 2024 HD trucks and 2024 SUVs

• 24-NA-168 for Hummer 2022-2024

• 25-NA-098 for Corvette and MY2025 Hummer

If the radio is not at latest software level update the radio, clear all codes and recheck for concern.

1.3 If the customer came in with a phone connectivity concern, please make sure that the customers phone is

updated to the latest iOS or Android software before proceeding further.

1.4. For audio concerns including intermittent 1-2 second loss of audio or loss of audio for an entire ignition cycle

see PIT6406.

1.5. If concerns continue perform a radio data wipe by going to SPS, select A11 radio, then select *ONLY USE if

following PIT6209 instruction* Radio Data Wipe File and follow the on screen instructions.

Note: For the purposes of this PI please ignore *ONLY USE if following PIT6209 instruction* and perform the data

wipe.

Note: Once this operation is performed, the customer will need to log back into their google account, and repair any

mobile devices that were saved on the radio

1.6 If concerns continue disconnect, inspect, and reconnect all related connections, clear any codes and recheck for

concern.

1.7 After the Date wipe has been performed, if concerns are still present for the symptoms below DO NOT

REPLACE THE RADIO:

• A complete loss of audio over an Ignition cycle or short cuts in audio mentioned in PIT6406.

• The Radio display is going blank or black, but always recovers.

• Phone connectivity issues.

DO NOT REPLACE THE RADIO for these issues as it will not correct the customer's concern. Engineering is aware

of the issue and investigating the root cause we ask to please be patient until a resolution is published

1.8 If concern is still present and is not a software anomaly mentioned in step 1.7, these radios are currently

restricted through the Electronic Service Center (ESC). Please contact your preferred ESC to order the new radio.

The ESC will require a response to the attestation question before authorization will be provided. Attestation

question: Have you followed, reset the module, installed the latest software, disconnect and reconnect, and that the

radio still requires a replacement?
Bulletin No.: PIC6602Q
December, 2025
Page 3
Warranty Information

For vehicles repaired under the Bumper-to-Bumper coverage (Canada Base Warranty coverage), use the following

labor operation. Reference the Applicable Warranties section of Investigate Vehicle History (IVH) for coverage information.

Labor

Operation
Description
Labor Time
2810335
Update radio to latest

software
Use

Published

Labor Time
*3480578
Disconnect and reconnect

Radio module
1.0 Hrs.
*3480688
Radio Replacement per

TAC Instructions
MY22-25

Hummer SUV

and Pickup

1.1 Hrs.

MY22.5-25

Silverado and

Sierra 1500

1.2 Hrs.

MY24-25

2500/3500HD

1 Hr.

MY24-25

Corvette 1.3

Hrs.

MY22-24

Tahoe/

Suburban/

Yukon/Yukon

XL 1.1 Hrs.
*This is a unique Labor Operation for Bulletin use only.
Version
16
Modified
04/30/2025 Created on.

05/01/2025 - Updated Correction.

05/13/2025 - Updated Correction.

05/29/2025 - Updated Models.

06/19/2025 - Update to the Correction.

06/30/2025 - Update to correction

07/23/2025 - Updated correction to ESC restriction

07/30/2025 - Update to correction

08/14/2025 - Updated to correction to ESC restriction

10/03/2025 - Updated to change labor operation for programming per BQM request

10/08/2025 - Updated to add note to not replace radio for audio issues

10/17/2025 - Updated to add 25-NA-318 for 2022-2023 LD Trucks and 2024 HD trucks

10/23/2025 - Updated to add 25-NA-318 for 24 LD Trucks and 2024 SUVs

11/11/2025 - Updated to the correction

11/18/2025 - Updated to the correction

12/02/2025 - Updated to the correction
GM bulletins are intended for use by professional technicians, NOT a "do-it-yourselfer". They are written to inform these

technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper

service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions, and know-how to do a job

properly and safely. If a condition is described, DO NOT assume that the bulletin applies to your vehicle, or that your

vehicle will have that condition. See your GM dealer for information on whether your vehicle may beneﬁt from the

information.
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