Mk8 1.1 Fiesta - fault codes and electrical issues

Mk8 1.1 Fiesta - fault codes and electrical issues

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LPH

Original Poster:

333 posts

173 months

Thursday 21st March
quotequote all
Just bought a Mk8 (2018MY) 1.1 Fiesta for my son to learn to drive.

All good when purchased (privately) but air con needed re-gassing.

When I got the car home after buying it I hooked it up to Forscan and checked for codes etc. There were some stored codes which I cleared. After using the car a few times I did the same and found codes some related to AC pressure etc. which I expected but lots of others that all had a common theme, and open circuit or earth issue. Things like rear left taillight, handbrake switch, fuel pump, horn relay etc. Mostly listed under the Body Control Module section.

Cleared again and used the car.

Took it for an aircon re-gas today. They did the usual tests, pressurised the system, checked the pressure switch operation and AC clutch etc. and all checked out fine. Re-gassed the car and then tested the AC. The radiator fan won't come on as it should when you switch on the AC. They plugged in a scanner and all the signals and info checked out - just no movement of the fan. So looks like the fan might be knacked. Not a massive issues and fairly easy to replace.

But....when they were doing the AC and checking with the OBD reader and airbag light came on. Never seen that before. They cleared it and it didn't come back. I drove the car home and all was OK. Then whilst I was sat checking codes again on Forscan it threw an airbag light and it won't go out. Checked other codes and again I've got lots of 'ground' type faults. I've run the PCM, BCM , GFM, ABS etc. etc on demand tests using Forscan and they all return no issues. And everything works in the car, there are no issues 9apart from the rad fan and airbag light now). The car never throws a general MIL.

I'm thinking it's a dodgy earth somewhere? I checked the BCM and fuses under the bonnet and they all look OK. Fuses under the glovebox inside look OK too. No obvious corrosion or anything.

Anybody had anything like this before? Any advice would be gratefully received!

Cheers

Edited by LPH on Thursday 21st March 16:45

finlo

3,763 posts

203 months

Thursday 21st March
quotequote all
Have you checked the battery terminals are tight?

LPH

Original Poster:

333 posts

173 months

Thursday 21st March
quotequote all
I presumed they were but I will defo check this evening!

LPH

Original Poster:

333 posts

173 months

Thursday 21st March
quotequote all
All very tight!

anyoldcardave

106 posts

67 months

Saturday 23rd March
quotequote all
The Battery is always a good place to start with Fords, even if they start or turnover the car, before going any further make sure the battery is 100%, and it is charging correctly, it is probably a 6 year old battery.

A very slight drop in efficiency can cause all sorts of random issues.