Engine Management Light

Davie · Post by **Davie** » Mon Mar 05, 2007 8:51 am

Help!! at the weekend the the MIL came on while out for a run, never had this happen before so slightly concerned. The car seems to be running fine and no unusual noises or loss of power.

I assume this means a trip to MMC, but is there anywhere else local to Aberdeen that could diagnose the problem as it's a bit of a journey to get a light turned off!!

robin · Post by **robin** » Mon Mar 05, 2007 9:33 am

The fault codes are all in the manual - any OBD-II compliant tool will be able to read back the fault codes and reset the light.

Most non-franchised workshops will by now have a generic tool that will work on modern cars, so take the vehicle there and let them read back the codes - make sure you tell them you want the codes written down before they clear them all - then post the codes and let the SE do it's magic.

The OBD-II connector is in the footwell somewhere - I think it hangs down in the middle between driver and pax sides.

BTW, a lot of the codes are common, so the tool will probably offer up a translations like:

P-0000 #2 O2 SENSOR FAULT

But best make sure you get the actual codes too, as there can be some differences in interpretation.

Cheers,
Robin

Davie · Post by **Davie** » Tue Mar 06, 2007 8:43 am

cheers...I'm getting it checked today and will post the error code tonight

Gareth · Post by **Gareth** » Tue Mar 06, 2007 8:57 am

Davie wrote:cheers...I'm getting it checked today and will post the error code tonight

Out of interest, where?
I was going to suggest somewhere like Vauxhall (Belmont)

Davie · Post by **Davie** » Tue Mar 06, 2007 11:54 am

One of my friends has the Dee garage in Banchory and he can get hold of the OBD tool at short notice.

Davie · Post by **Davie** » Tue Mar 06, 2007 6:34 pm

The error code was P1302, which the computer listed as cylinder 2 miss fire, can anyone confirm that this is the correct diagnosis?? Should I be worried??

Novice Racer · Post by **Novice Racer** » Tue Mar 06, 2007 6:46 pm

I had a no. 3 misfire and the filth (MMC service and repair) said I would need a new set of coils and an engine strip to fit them.

Thought "fcuk that" and have had run the car for a year with no similar problems.

Stealers - bunch of chancers.........

NR

robin · Post by **robin** » Wed Mar 07, 2007 2:06 am

P1302

Misfire level causing catalyst system damage.

Misfire detected which could cause possible damage to the catalytic converter. Fluctuations in crankshaft speed are used to determine misfire.

Criteria: Misfires on all cylinders evaluated over 200 revs > 10%

Secondary enable conditions: P0300-P0304 active.
Disable by faults: P0122, P0123, P0107, P0108, P0117, P0108
Time required: 200 revs continuously.
Potential failure modes:
Spark plug fault.
Plug lead loose or faulty.
Ignition coil circuit problems.
Ignition coil problem.
Low compression in cylinder.

Limp home: None.
Note: This fault will be indicated with a flashing 'check engine' light during the misfiring condition.

robin · Post by **robin** » Wed Mar 07, 2007 2:15 am

So the above is the blurb from the book.

P0300 is random misfire.
P0301-P0304 is misfire on cylinder 1/2/3/4.
P1301 is misfire level causing emissions increase.

In theory you should have gotten at least one or two of these out too (the ECU stores multiple trouble codes).

The fact that you got P1302 as #2 cylinder misfire makes me think that it was P0302 not P1302? Anyway, perhaps it's both - i.e. it was P1302 which is a general misfire fault combined with P0302 which is specifically cylinder #2 misfiring and the tool combined them into a single read out.

Either way, I would guess that you have an ignition fault on one or more cylinders (1&4 and 2&3 share a pair of coils so coil faults will show on cylinder pairs) - with a bias to the fault being on #2 cylinder (that's the second one in from the drivers side, I imagine).

It's easy enough to remove the big plastic cover and then whip off the two coil packs (two small bolts each) and whip out the spark plugs while you are at it.

Any damage to the plugs, or one plug having a different colour from the others will be of interest.

Check the leads for signs of arcing - there may be carbonised patches on them if this is happening (also, running the engine in a dark garage with the cover off might show up any arcs as you'll see the blue flashes).

Check the lead ends to make sure they fit on the plugs well.

Did the garage clear the faults too? Assuming they did it would be interesting to know if it has already come back. A persistent misfire will cause one of the P0300-P0304, P1301 and/or P1302 quite quickly.

Cheers,
Robin

Davie · Post by **Davie** » Wed Mar 07, 2007 11:10 am

Thanks for all the information, I'll check the plugs etc at the weekend.

The garage cleared the error and the light has not come back on.
Again thanks for you help!!

Novice Racer · Post by **Novice Racer** » Wed Mar 07, 2007 12:01 pm

robin wrote: It's easy enough to remove the big plastic cover and then whip off the two coil packs (two small bolts each) and whip out the spark plugs while you are at it.

Interesting. I was told by MMC that the engine would need "stripped" and the total cost, including new coils, would be "about £600." Remember nearly choking.

Just goes to show, trust the Jedi master, not the stealer.......

NR

hendeg · Post by **hendeg** » Wed Mar 07, 2007 1:28 pm

Davie wrote:Thanks for all the information, I'll check the plugs etc at the weekend.

The garage cleared the error and the light has not come back on.
Again thanks for you help!!

Davie,

My engine managment light is on as well.

The first time, I took it to MMC and they said it was because I have the sports exhaust and it could come back on at any time. I only drove a few miles before it came back on.

I put it into Jim King for an MOT not long after and it had a leak in the downpipe. I assumed that was the problem when it went to MMC and they never noticed.

It did last a while before it came back on again. I've been driving with it on, but I suppose I should really check it out. Is there any chance that your mate still has the tool and would be able to have a look?

Cheers,
Gary.

Davie · Post by **Davie** » Wed Mar 07, 2007 1:57 pm

Gary,

He actually took me round to the garage next door and used their tool. It cost me £20 but better going to somebody you konw.

mac · Post by **mac** » Wed Mar 07, 2007 2:40 pm

Depending on the age of the car you might find that it's the coil pack on it's way out - I'm having to replace them on Mandy's car as we can feel the misfire and investigation show the contacts starting to fail.

If it's causing a mis-fire enough for the MIL to illuminate then it should be pretty noticeable - whip it out (as described by Robin) and pull off the rubber boot to view.

Mac

robin · Post by **robin** » Wed Mar 07, 2007 2:58 pm

Pretty sure new coil packs are expensive - would consider sourcing them from Geary as seconds or a scrapper (MGTF would have these same plug-top coil packs I think).

Cheers,
Robin