ST170 Engine Management Light

DevilsAdvocate · 30 Jun 2008 at 19:13

Hi Folks,

Went to view a Focus ST170 this evening, all seemed well enough except the Engine management light was on. The chap selling it said it was due to the battery going flat before hand and because it had detected low volts, the light had lit up. Sound genuine enough? What other possible problems could there be? And what costs involved?

The chap said he'd get it reset, but I don't want it coming back on again the minute I drive away! Thanks guys.

Defcon5 · 30 Jun 2008 at 19:48

Sounds possible, but then again it could be something major

DevilsAdvocate · 30 Jun 2008 at 19:51

The car drove fine on the test, no knocks and it pulled well. Have read online about possible Lambda sensor failure causing this, expensive fix?

lordrobs · 30 Jun 2008 at 19:58

DevilsAdvocate said:
Hi Folks,

Went to view a Focus ST170 this evening, all seemed well enough except the Engine management light was on. The chap selling it said it was due to the battery going flat before hand and because it had detected low volts, the light had lit up. Sound genuine enough? What other possible problems could there be? And what costs involved?

The chap said he'd get it reset, but I don't want it coming back on again the minute I drive away! Thanks guys.

The guy is selling his car with a fault light on the dash and claims its for a genuine reason and can simply be reset... so instead of getting it reset he just leaves it so potential buyers think twice about the car.

Either he is a plank or he's got something to hide, either way- walk away.

IMO of course

Firegod · 30 Jun 2008 at 20:11

Engine Management light I'd say was the lambda also. But if it's anything like the Fez it can take awhile to clear, unless taken to Fords and they can reset it for you. Because I have a sports-cat I had to get a MIL-Eliminator to get the light to turn off for me.

I guess if the cat was knackered it would also come on?

I wouldn't say battery though...

jon.bda · 30 Jun 2008 at 20:29

DevilsAdvocate said:
The car drove fine on the test, no knocks and it pulled well. Have read online about possible Lambda sensor failure causing this, expensive fix?

We had one in at work a few months back with the same thing, we kept on putting the light out but it would come on again after a few days to a few weeks. Even after fitting a new 02 sensor i think the light actually came on once more for the same thing before they finally chopped it in for an A3...

SoliD · 30 Jun 2008 at 21:57

Leave it alone, I would not buy one with engine light on unless it had been diagnosed and was due to be fixed before buying.

Goliath · 30 Jun 2008 at 22:08

Walk away from it. Seriously. Don't even go there. There are rafts of them knocking about (a quick search on Pistonheads reveals 8 pages worth) so you can afford to be picky.

Apart from anything else, if the battery is not charged/charging properly it's the battery warning light that comes on, not the engine management light.......

Overlag · 30 Jun 2008 at 22:10

DevilsAdvocate said:
Hi Folks,

Went to view a Focus ST170 this evening, all seemed well enough except the Engine management light was on. The chap selling it said it was due to the battery going flat before hand and because it had detected low volts, the light had lit up. Sound genuine enough? What other possible problems could there be? And what costs involved?

The chap said he'd get it reset, but I don't want it coming back on again the minute I drive away! Thanks guys.

it could mean anything really. id walk away plenty of other ST170s about?

ethos · 30 Jun 2008 at 22:11

Or if you are keen.... get him to include a diagnostic session with ford? It MIGHT be something that simple.

Duke · 30 Jun 2008 at 22:17

Could also be ABS sensor. Had that with my Puma anyway.

Torch [P4] · 30 Jun 2008 at 22:21

a dead battery wouldnt throw up a fault code, however if a sensor were unplugged and then the engine started it would throw a code into the ecu which has its own battery backup
having experienced this first hand recently its a royal pita as you need to first read the code and then delete it to see whether or not it comes back.

could be genuine enough tho, if you are genuinely interested get him to take it to a main ford dealer and get the codes read and reset (cost me £30 to have an airbag fault code cleared on my old focus after a false trigger)