Countries:

CANADA, MEXICO, UNITED
STATES

Document ID: IK0800686

Availability:

ISIS, Bus ISIS, IsSIR

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0

Major System:
Current
Language:
Other
Languages:

Electrical

Created:
Last
Modified:

7/11/2025

Author:

Brandon
Akridge

Viewed:

81

English
NONE

7/18/2025

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Title : Radio Clock is Freezing
Applies To : Next Gen CE Bus

CHANGE LOG
Please refer to the change log text box below for recent changes to this article:
07/18/2025 - Initial Article Release

DESCRIPTION
The radio may not change/update the displayed time. The time will stay frozen until a button or dial on the radio is used, and
then it will update to the current time. This iKNow will provide the steps to update the radio software to correct this condition.
This applies to Radio part numbers 4275485C91 and 4275486C91.

SYMPTOM(s)
Customer Observations or Concerns:
The Radio clock time will freeze and not continue to move forward.

SPECIAL TOOL(s) / SOFTWARE
Tool Description

Tool Number

Comments

USB Flash Drive

SERVICE PARTS INFORMATION
None

Instructions
Obtain Locally

DIAGNOSTIC STEP(s)
Step Action

Decision
Yes: Update the radio software following the
Repair Steps.

#1

Is there a driver complaint that the clock is
displaying an inaccurate time?
No: This iKNow does not apply

REPAIR STEP(s)
You will need to download the radio software and place the files onto a USB flash drive. Then insert the flash drive into the radio
and update the radio software.

Download radio software to your computer:
1. Radio software ZIP file (Click Here)
2. Open the .zip folder
3. Extract the folder to your computer desktop. To do this, right-click on the zip file and select “Extract All…”. Keep the default
settings and select “Extract.”
4. Select Desktop and click OK.
5. Once the file is saved. Confirm there are three files in the folder that was created and opened. The three files should be
“MCU_H.BIN”, “MCU_I.BIN”, and “MPEG.BIN”. See example below.

Move the files to a USB Flash Drive
Once the files are on a flash drive, you can use the flash drive to update multiple radios/vehicles.
1. Insert a USB Flash Drive into the computer. The capacity cannot exceed 32 GB and the file format must be FAT32
2. Drag the three files into the root level of the USB Flash Drive. The files should not be in any folders.
3. Confirm the contents look like the following image with files in the USB folder.

4. Remove the USB Flash Drive from the computer.

Install the Flash Drive into the radio and update the software

Programming is a two-part process.
A. Update MCU
B. Update DEC
Steps 1-6 update the MCU
Steps 7-10 update the DEC
Steps 11-17 verify that the MCU and DEC are up to date and complete the repair
1. Turn the key to Accessory = ON. If the radio is not yet powered on, press the radio power button. Make sure the radio is fully
powered on, not in standby mode (ensure audio is playing).

2. Plug the USB Flash Drive into the USB Port on the front of the radio. The screen will display the following sequence: “USB”
→ “READING” → “USB ERROR”. This is okay
3. Press and hold the “RADIO” and “5” buttons at the same time to access the hidden software menu

4. The radio will display its current software version on the screen.

5. Turn the knob until “UPDATE MCU” is displayed. Press down on the knob, and the screen will now say “LOAD FILE”. After a
few seconds, the radio will automatically start updating.

6. The radio is now updating. Wait for the update to finish. Do not power off the radio or remove the USB Flash Drive. When the
MCU update is complete, the radio will automatically restart.
(Image below is showing at 9% complete)

7. After the restart, press and hold the “RADIO” and “5” buttons at the same time to access the hidden software menu again.

8. Turn the knob to scroll through the options. This time, select “UPDATE DEC”. Press down on the knob to begin the DEC
update.

9. The radio will display “LOAD FILE” → “INITIAL” and then begin updating. The time between “LOAD FILE” and “INITIAL” may
vary.

10. The DEC is now updating. Do not power off the radio or remove the USB Flash Drive. When the DEC update is finished,
the radio will automatically restart.
(Image below is showing 5% complete)

11. After the restart, confirm the radio has successfully updated the MCU and the DEC to the correct versions. Press and hold
the “RADIO” and “5” buttons at the same time to access the hidden software menu one more time.

12. Once in the hidden software menu, confirm the screen displays “MCU-02072H” or “MCU02072I”.

13. Turn the knob once and confirm the screen displays “DEC-V0.34”.

14.
15.
16.
17.

The radio is now updated to the latest software.
Turn the key position to OFF.
Remove the USB Flash Drive.
Software update is complete.

WARRANTY INFORMATION
Warranty Claim Coding:
Refer to the Warranty Coding Manual for Group and Noun Codes.

Standard Repair Time(s):
Refer to the SRT Manual for Repair Times

OTHER RESOURCES
Master Service Information Site

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