Hi guys

me again 👋

For anyone new, I have a Mk2 Focus, Titanium spec 3dr in (in my biased opinion) the best colour, Panther Black. 92k miles, shes a very pampered princess.

another error message thats popped up on the dash is "engine systems fault" > "brake light fault" and leaves me with the red warning bulb on the dash.

I've plugged in with the ever reliable forscan and have got the following:
 

Code: P0571 - Brake Switch A Circuit

Additional Fault Symptom:
 - Signal is Above Maximum Threshold

Status: 
 - DTC Present at Time of Request
 - Malfunction Indicator Lamp is Off for this DTC

Module: Powertrain Control Module

Diagnostic Trouble Code details

Brake Switch A Circuit

Noise on the CAN derived signal is greater than the calibrated limit.

CAN message times out.

Fault status reported over CAN.

The number of BLS transitions with no BPP switch transitions exceeds the calibrated limit.

This DTC may be caused by :

Electrical Interference

CAN communication bus fault.

Faulty switch operation.

To clear this DTC, it is necessary to reset the KAM.

now. symptoms: none.

brakes work.
lights come on when the pedal is pressed and the switch engaged.
ABS engages if I'm going fast enough and I stamp hard enough 😁.
no CEL.

reading the blurb, I'm guessing this is an electrical interference issue from the cluster? wheel speed sensor? open circuit? it comes not long after I had the cluster "repaired" for cheap. my concern is, it wasnt done properly. (but it its worth to note, i THINK the LCD panel is dying as the top row of matrix text is corrupted/doesnt show - possible source of electrical noise?

resetting the KAM, can I do this with the freebie Forscan, or, do I need grown-up toys to do this?

I'll be taking the car into the mechanics to, hopefully, put a long standing running fault to bed (fuel vapour solenoid/purge valve) so any advice that can be offered will be appreciated. I'm waiting on parts at the mo so I have a little time to poke and prod before I take it back in.

The instrument cluster solder issue usually requires all the old solder to be removed and replaced with new. There are resistors at the end of the cab bus leads and the solder there is another point as well as the plug pins. All possible solder joints should be resoldered, not just reflowed.

Another area with checking is the gem/Fusebox and it’s plugs above the passenger footwell.

Both common issues 

note battery should be disconnected before unplugging the gem/BCM fusebox

1 hour ago, kingarthur83rd said:

resetting the KAM, can I do this with the freebie Forscan, or, do I need grown-up toys to do this?

Disconnecting the cars Battery resets the Keep Alive Memory.

Probably best to leave it disconnected for 20 minutes or so.