Hi

I have been experiencing a couple of issues with my 2005 fiesta st.

1. Randomly, when driving the dash, stereo and central locking will reset and then the dash will flash EAC FAIL. When this happens, the stereo stops and the central locking activates. It all resets together and then works as normal. And once it happens it does it again and again until I restart the car.
2. At the same time as above, occasionally the engine management light comes on. It will stay on a little while and then if I drive it very hard it will go out.

I have used a diagnostic machine and the dtc shown was #o - P 1900.

If anyone could help it would be great; losing the will here!

Thanks

James

This seems logical, possibly

P1900 Ford - Output Shaft Speed Circuit Intermittent Malfunction

Possible causes

- Output Shaft Speed sensor damaged, or not installed properly
- Harness connector not properly seated
- Harness intermittently shorted, or open
- Harness connector damaged

P1900 Ford Description

The output shaft speed sensor signal to the PCM is irregular or interrupted.

Which sensor is that tho? Abs or dedicated sensor?

Check your battery connections, especially the earth. Sounds like a dodgy earth somewhere.

anybody got a list/locations of connections to check? And contact cleaner?

Also, what will happen if I disconnect the battery?

Will I need the radio code?
Will I lose my bluefin map?

Thanks

It should remember the bluefin but no the radio code.
I personally think there is an earthing fault from what you're saying, ford seemed to like building earth's in corrosive prone places to keep us on our toes, but then again it could just be a wire rubbed through

So I will need the code? I don't have it lol!

ebay! You pay like £1.50 and you email your reg number and phone number then they text it you normally. the guys you buy it off basically pay for the app or program and do it to reclaim the money. I had to do it with a beat up old Focus. Then when you have it write it down in the manual and a few other places just in case hahaha
Although you can get it from a ford dealer I think?

Ahh all good then!

Thanks

Alternator knackered

Would the battery not be flat by now?

Well in theory the battery would be gone as its not charging

The car starts well and battery is fine.