Fiesta MK7.5 5" MFD5 Retrofit – SWC Audio Buttons Fail

[mk7_reaper]

Hi everyone,

I’m looking for input from members who have already completed a 4" → 5" MFD5 display retrofit on an EU Ford Fiesta MK7.5, as I’m currently diagnosing a very specific steering-wheel control issue that only appeared after the retrofit.

I’ve been working through this for several days and I’m confident the issue is not related to wiring, clockspring, or SCCM hardware, but instead points to a module compatibility, firmware, or configuration interaction between the FCDIM and APIM.

TL;DR

If you have a working 5" MFD5 retrofit (audio + voice steering-wheel buttons continue working after 20–30 minutes of driving), please share your FCDIM part number/strategy and APIM part number/calibration (NA or RB).
I’m trying to determine whether my issue is caused by a DC-strategy FCDIM, an outdated APIM calibration, or a configuration incompatibility.


Vehicle & retrofit background

Vehicle

• Ford Fiesta MK7.5 (EU)
• Factory SYNC 1.1 (non-navigation)

Hardware BEFORE retrofit

• 4" FCDIM: F1BT-18B955-SA
• Sony non-SATNAV stereo fascia: C1BT-18K811-SA
• Sony ACM: E1BT-18C815-HK
• Steering wheel module: AV1T-14K147-AA
• APIM (SYNC 1.1): D1BT-14D212-NA
• No reverse camera

Hardware AFTER retrofit

• 5" MFD5 FCDIM: F1BT-18B955-DC
• Same stereo fascia
• Same ACM
• Same steering wheel module
• Same APIM (SYNC 1.1)
• Added aftermarket reverse camera (fully functional)

Configuration changes made

Only configuration options were changed using FORScan.
No manual As-Built hex editing was performed.

IPC

• Touchscreen type → With Display, No Touchscreen, MFD5
• Park Assist Camera → Enabled

APIM

• Display Feature Set → MFD5

Symptoms (started only after retrofit)

• Steering-wheel audio and voice buttons work normally after ignition
• After a few minutes of driving, all audio/voice SWC buttons stop responding, including:
  • Volume up/down
  • Track next/previous
  • Centre voice command button
  • Voice button on indicator stalk
• Cruise-control buttons continue to work at all times
• Audio playback, SYNC functions, and reverse camera continue working normally
• After a full vehicle sleep (~30 minutes locked), audio/voice SWC works again temporarily

Troubleshooting already performed

• Rebooted modules individually and in combination:
  • APIM
  • FCDIM
  • ACM
  • IPC
  • BCMii
• SYNC master reset
• Battery disconnected for ~1 hour
• Verified wiring was untouched during retrofit
• Verified clockspring and SCCM functionality (cruise buttons always work)

Why I believe this is FCDIM / APIM-related

Based on the observed behaviour:

• SCCM and clockspring are clearly functioning (cruise never fails)
• CAN wiring is intact
• Steering-wheel button messages continue to be sent
• Only audio/voice SWC processing stops after runtime

This strongly suggests a logic or firmware issue where the FCDIM or APIM stops handling those events after a period of operation, rather than a physical hardware failure.

Current module details (problematic setup)

FCDIM – Front Control / Display Interface Module

• Part number: F1BT-18B955-DC
• Calibration level: F1BT-18B955-DC
• Strategy: F1BT-14D358-DC

APIM – SYNC 1.1

• Part number: D1BT-14D212-NA
• Calibration level: D1BT-14D212-NA (latest known appears to be D1BT-14D212-RB)
• Strategy: E1BT-14D205-AH

What I’m looking for from members

I’d really appreciate replies from anyone who has completed this retrofit successfully and has no long-term SWC issues.

If your setup works correctly, could you please share the following FORScan module details:

FCDIM

• Part number
• Calibration level
• Strategy

APIM (SYNC 1.1 only)

• Part number
• Calibration level
• Strategy

Please also confirm:

• Reverse camera enabled (factory or aftermarket)
• Audio + voice steering-wheel buttons still work after 20–30 minutes of driving
• APIM is SYNC 1.1, not SYNC 3

Goal

I’m trying to determine whether this issue is caused by:

• A limitation or bug in DC-strategy MFD5 FCDIMs
• An APIM issue resolved by updating calibration from NA → RB
• Or a known incompatible combination of SYNC 1.1 with certain MFD5 variants

Any confirmed working data points will help not only me, but anyone else attempting this retrofit in the future.

Thanks in advance for reading, and apologies for the long post, I wanted to include enough detail to avoid guesswork and make troubleshooting easier for everyone.