Update
Disconnected the battery and left it disconnected for some days as simply didnt have time till today when I got home early from work. Did all that yiu said including vaseline. Car started fine and engine light was still on but I thought what the heck. Drove off and punched the gas to see what would happen. Accelerate great. Hit 70mph on straight road and drove 23 miles in total. Car never cut out once and I stopped the engine couple of times and restarted t be surenit would work and it did

All this time engine light still on. What does this mean? Is problem fixed but code still stored or what?

 

- you might need to have the code cleared, but ;
- it might self clear after so many known 'good starts', so ;
- continue using it daily and see if it self clears

Best of luck !

 

I've been waiting for this one -- about the battery I mean. If the battery connexions aren't quite right, it could introduce a degree of a 'wierd resistance*' into the starter circuit of hundreds of amps, putting starter-motor "hash" onto the 12volt rail to microprocessors at a voltage of about 9volt from the battery-during-cranking. This could lead the micros to be vulnerable to glitches.
If I fit a battery to a car, I do them up "soft-tight" the rotate the connector backward and forward a few times to ensure a good connexion. Some grease is a good idea too, it will keep any moisture away.

Leedsman.
*Wierd resistance". This is where you get two dis-similar metals (lead and probably brass/copper in this case) plus some oxide secured together acting like an unintentional bad rectifier + some resistance and lot of instability.
Indeed, there were "copper oxide rectifiers" and "selenium" rectifiers in the old days, long since displaced by silicon diodes which are much more efficient and miles cheaper.

 

I call what Leedsman's doing, "Lapping in", as you would do to Cylinder Head Valves to mate to head. This makes a proper fit and reduces high spots, between battery terminal and connector. But saying that a good mechanic usually winds the connector back and fourth over battery stud during tightening.

 

Would an AA guy be able to clear the code

 

Possible, they can only talk to the car at an OBDII level -which is just emission related faults.

Give it a few days of use and see if the indication clears

Regards
Richard

 

Good news is the engine light finally went out when i was driving and I am very happy with that result, thank you all. Saved me having to pay out unnecessarily

Bad news is the Optima was flat in 2 days straight so clearly something is draining the battery. This time I made 100% sure no lights were left on and key was removed at right point

how easy/hard is it to diagnose a batteryndrain issue on these phones

 

This issue of battery terminal condition should be added to the list of common faults that seem to be accruing re. GVs.
I can remember in the old days a kind of white sulphation/oxidation used to grow from the terminals of the "flooded" batteries then in use until it was half an inch thick. Simply pouring boiling water from a kettle got rid of it instantly. I've also seen copper connectors half eaten away with fumes from the battery. Come to think of it, even the spring-connectors to the batteries in my tv handset need a scrape now and then.

So...all these "glitch" problems we've been having with the micros might just be down to imperfect connexions to the battery. This does make electronic sense when you take into account the very heavy current taken from the battery by the starter motor; also dragging it down to 9volt, and putting serious glitches onto the battery's 12volt line from sparking between brushes and commutator. Remember these starter motors make around one horse power, so the sparking will be heavy.

Remedy?
I used to file the inside of the two connectors with a half-inch round file, and scrape the lead posts with a short-bladed knife. Then a licking of grease on the posts and connectors before doing them up. The grease would stop any further sulphation. And now you must be even fussier and ensure the -ve cable connexion to steel body/chassis is good, and the grounding strap from engine/transaxle to body/chassis is also good.

Now we can use the boiling water to make the tea, which is how it should be...

Leedsman.

 

GoTo Maplins and get this 1 ohm 10 watt resistor [Code: H1R] then solder it between a bit of wire and 2 clamps, and put your test meter where the video tells you, and pull the fuses the video tells you. You should be under 35-40mV.

NOTE:

- the car needs to be tested only after its been switched off, locked up and alarmed for 15+ minutes
- REM to tape up the bonnet alarm turret / post or you will set your alarm off

 

Whats alarm turret?