Ford Focus MK2 acceleration reduced & transmission malfunction fix

Hi,

I got a 2008 Ford Focus MK2 that suddenly started to go crazy. Here is a list of all the issues:

• Instrument cluster intermittently stopped working while driving, all the gauges go limp to 0.
• Engine fault light was turned on.
• Acceleration reduced message on the instrument cluster screen.
• Transmission malfunction message on the instrument cluster screen.
• Sometimes the car would not start.
• Went into limp mode, refusing to rev over 3000 rpm and sometimes unexpectedly changed to a lower gear.
• Significant increase in gas usage.
• No AC while instrument cluster is down.

It all started by displaying the acceleration reduced and transmission malfunction messages, then after a while it escalated.

Video example while driving: https://gfycat.com/foolhardyseparatebellsnake

Using an ODB2 connector the trouble codes indicated that some tests failed and there was a CAN communication problem, unfortunately I didn't save the codes.

Using the IC test mode I remember that I saw these codes and another one that I can't remember:

• DTC #01 - D900
• DTC #02 - E510

The reason for those issues:

Apparently there's a computer module in the instrument cluster that is connected to the PCM. Since Ford was using an environmentally friendly unleaded soldering lead instead of regular soldering lead to connect the CAN interface to the PCB, it has a tendency to crack with age and lose connection.

The fix:

Re-soldering that connector that is behind the instrument cluster fixed all those issues for me.

You need to remove the IC and disassemble it (see linked videos for reference).

Then all you need is to re-solder the connector pins on the other side of the PCB:

I didn't record how I did it since I didn't think it would work, but here are a couple of YouTube videos that I used for reference:

Short - shows how to remove the cluster.

Comprehensive - shows how to correctly disassemble the cluster and re-solder the connector.

After re-soldering I cleared the codes using an ODB connector.