Mercedes Viano (2011, Model 2012) - CANbox issue.

[rbro]

Hello

I have some issues with a CANbox for an Android car radio.
I hope you can help. Please see summery below. I did some debugging with ChatGPT+CoPilot and CoPilot recommends to replace the BZC1.20 with BZ11.20 - is that the best solution?

Thank you.

/Rasmus


Android Head Unit – Technical Summary for Support

Below is a complete summary of the information I provided, the diagnostic tests performed,
the results, and the recommended solution.

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1. Device Information
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• Model: MT8163 AJ Android Head Unit
• Android Version: 15
• Kernel Version: 4.9.117+
• RAM: 2 GB
• Storage: 64 GB
• Platform: MT8163
• Screen: 1280x720
• Touch Panel: GT9xx (1080x600)
• Build Number: AJ_2025.10.11.09_3_2424
• MCU Version: CVD1810-WJ_24.09.21_399
• CAN Settings: Hiworld -> Benz/SMART -> ABCE_W02
• CAN Version: 40.0.1.20251103
• Current CAN‑box model: Hiworld BZC1.20 (H1N4BZC10A)
• Vehicle: Mercedes-Benz Viano W639 (Dec 2011, model year 2012, facelifted version)

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2. Problem Description
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• The screen goes black for approx. 33 seconds, then turns on for about 3 seconds.
• The device does NOT reboot – only the display power cycles.
• The issue ONLY occurs in the vehicle.
• When powered on a stable 12V bench PSU, the head unit works perfectly.
• When installed in the car, the CAN‑box is the only component connected besides ACC, B+, GND.
• Reverse gear popup appears intermittently, even when ACC is bypassed.

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3. Diagnostic Tests Performed
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A) ACC Bypass Test
• The ACC wire from the CAN‑box was disconnected.
• ACC was directly bridged from B+ (constant 12V).
Result:
→ The screen stayed ON permanently with no blackouts.
→ This confirms the CAN‑box was sending an unstable ACC signal.

B) CAN Signal Behavior
• Even with ACC bypassed, reverse gear popups still appeared occasionally.
Result:
→ Confirms unstable or incorrect CAN messages from the current CAN‑box.

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4. Conclusions
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• The ACC output from the Hiworld BZC1.20 CAN‑box is unstable.
• This CAN‑box is NOT fully compatible with Mercedes-Benz W639 (2011–2014 facelift).
• The unstable CAN‑ACC signal caused the display to enter power‑save / blackout cycles.
• The radio itself is functioning correctly.
• A correct CAN‑box is required for full vehicle integration (ACC, SWC, reverse, etc.).

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5. Recommended Solution
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A different CAN‑box model must be used. Recommended compatible options:

1) Hiworld BZ11.20 (most compatible with W639)
2) Hiworld H1N4BZC03A
3) Hiworld H1N4BZC08A
4) ZC‑MB‑W639 (EU-market version)
5) RoadTop W639 CAN‑adapter

Most reliable & cheapest manufacturer‑compatible option:
→ Hiworld BZ11.20

Most reliable EU‑warehouse SWC‑compatible option:
→ ACR‑Hof W639 CAN‑adapter (Germany)

Note: None of these CAN‑boxes support OEM Mercedes PDC (parking sensor visualization).

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6. Current Status
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• ACC bypass proves the radio is fine.
• Current CAN‑box is incorrect for this vehicle.
• A compatible CAN‑box is required OR the radio must be rewired to ISO format.

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7. Important Additional Note (from ACR-Hof, Germany)
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ACR-Hof states:
• The CAN‑box must match the radio’s proprietary connector.
• Their EU CAN‑box will only work if the radio is converted to standard ISO wiring.
• They offer a conversion service for €179 including return shipping.

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End of Summary
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[HIWOORD SONG]

Our consulting engineers have confirmed that your vehicle model is more compatible with the BZ11 protocol box.

[rbro]

Can you confirm if the "Hiworld BZC1.20 (H1N4BZC10A)" is compatible or not compatible?
- if it is compatible, please advise how I can:
- - get stable ACC signal from CAN box to radio
- - remove the parking CANbus signal

Thank you