Ford Fiesta - EAC Fail | Technical matters | Back Room Forum

Mon 23 Apr 2018 23:02

Ford Fiesta - EAC Fail - Dainius Sutkus

Hi all,

I’m scratching my head right now as to what to do with my car. Recently I brought it second hand and have driving it for around 300 miles then at some cases engine light and pressure light came on momentarily for a couple seconds with a slight loss of power then everything would turn back ok. In that case I got it serviced asked them about it and they said they would plug it in. No fault codes, nothing. Car is all good runned for 300 further miles when the light came on again but this time after it went off a minute later the car completely died on me with an EAC Fail coming on at the mileage part of the dash. Got it towed off where I got it serviced they could not do anything as the car seems to be fully immobilised so when i turn the ignition on the padlock flashes.

When AA tried to fix it , I got the fault codes sent over to me as to i’m not sure how he managed to retrieve and even a proper garage couldn’t get any codes at all when immobilised :We have recovered your vehicle.Patrol found the following fault code/s:\N{ }\N{ }System : Engine control 1 - 07N / SIM 22\N{ }\N{ }U0122 - Unknown fault. Error Message : .\N{ }P0608 - Unknown fault. Error Message : .\N{ }P0646 - Air conditioner compressor relay. Error Message : Short to ground.\N{ }P1632 - Unknown fault. Error Message : .\N{ }P1794 - Battery voltage. Error Message : Outside specified range.\N{ }P2107 - Engine control unit (throttle valve monitoring). Error Message : Malfunction.\N{ }P0625 - Alternator charging voltage. Error Message : Value/signal outside min. range.\N{ }B1681 - Immobilizer signal. Error Message : Communication error.\N{ }\N{ }\N{ }\N{ } - Requires further investigation required at Garage.

I tried disconnecting battery, fuses seem all fine. Its a MK6 Ford Fiesta pre facelift 2005 reg 1.25L 16V petrol engine. Car is now over to fords hands but as which it take them over a week to even diagnose it for a ridiculous amount of £114. During this i’m here to ask for any guidance as to what I am in here for? Looked everywhere cannot find anything on what I am experience. Mileage is also 65k so not too bad. Any help would help thanks for reading :)

Reply | Report as offensive | Link

Tue 24 Apr 2018 07:34

Ford Fiesta - EAC Fail - hardway

Given that this cars electrical system is "Smart charge"I'd be looking/ testing there

smart charge means basically the PCM or computor ECU controls when it charges or not.

The PCM can dissable the alternator charge function during crank/starting for example.

First step in this test sequence would be a battery load test,

Chances are it's not going to pass this test.

They don't last for ever!

Reply | Report as offensive | Link

Tue 24 Apr 2018 09:30

Ford Fiesta - EAC Fail - Dainius Sutkus

The car was hooked up to booster by the AA (like the jump leads) that did not help. I believe the battery is only a couple months old?

Reply | Report as offensive | Link

Tue 24 Apr 2018 09:37

Ford Fiesta - EAC Fail - elekie&a/c doctor

With all these fault codes logged,a proper test plan needs to be carried out. Power and earth supplies to various components and fuse box and relays.The main fuse box is behind the glovebox.Small power distribution box behind battery. Not too sure why you need to take it to a Ford dealer. Take a look for a good indy diagnostic specialist.

Reply | Report as offensive | Link

Tue 24 Apr 2018 14:19

Ford Fiesta - EAC Fail - Dainius Sutkus

They insisted that they cannot do anything as the key does not link up wth the car and i have no spare key otherwise. When they try to scan they cannot retrieve anything even the AA managed to get something. AA did test the fuses snd they seemed all ok. Not the relays though. The fuel pump does switch on and the are clicking noises for about 8 seconds in the fuse box. The relays seem to tick for some reason. Its not at my drive right now its at ford as it was better to get to them asap rather than staying at my house as they may check it earlier then the booked date.

Edited by Dainius Sutkus on 24/04/2018 at 14:20

Reply | Report as offensive | Link

Tue 24 Apr 2018 09:53

Ford Fiesta - EAC Fail - hardway

I don't think hooking up a booster pack would help,

As stated it's a smart charge system so the PCM/ECU would still read the battery V.

As the Doc suggests get a good diagnostician.

Reply | Report as offensive | Link

Tue 24 Apr 2018 11:48

Ford Fiesta - EAC Fail - John F

Jeez! It took me 5mins of searching to just find out what EAC stood for! (electronic accelerator control).

I wonder if this link might help? It seems to be a common problem for Fiestas of this vintage.