Technical 1.6 fault codes query

[milleplod]

Evening all!

My son's 1.6 Dynamic threw up an 'engine fault' light a few days ago. Its been suffering from lumpy tickover/almost cutting out at low revs/stuttering at lower speeds for a few weeks too. I've cleaned out the throttle body, but no change.

A friend kindly stuck it on his diagnostic kit and the following codes came up - 300....D600....460....304....203....and 201. The codes came with the 'descriptions' to go with them.

Having lurked on here for ages, I've picked up all sorts of very useful info on the codes, and am now wondering if I'm interpreting this lot correctly! Am I right in (hopefully!) thinking that the culprit for the rough running may be the '304', which is 'intermittent cylinder 4 ignition failures'?

203 and 201 show 'intermittent cylinder 3 (and 1) injector SC + batt.v.' About 2 months ago, the battery completely packed in. Could these two, and also 460, 300 and D600 simply be down to that?.....it had been turning the engine over very slowly for a few weeks prior to giving up altogether.

Pete

 

[Deckchair5]

Evening Pete
Fault codes are usually given out as Letter then 4 digits eg P0154 so it's difficult to help you with the codes that you have shown. Some code readers seem to give shortened codes but it becomes difficult to be certain what they are

If you can get the full code then that would help us to give better answers otherwise it's a mystery and a guessing game

P0304 for instance is intermittent misfire cylinder 4 but that could be ignition or fuel injection problem

 

[milleplod]

Thanks for the reply.

The printout shows all the codes except the D600 without a letter. Each one has a 'description' at the side of it -

300 intermittent Ignition failures recognition
Ignition failures generic

D600 intermittent Electronic key
Incorrect key code

460 intermittent Fuel level sensor
Signal not feasible

304 intermittent Cyl 4 ignition failures
Ignition failure

203 intermittent Cylinder 3 injector
S.C. to +Batt.V.

201 intermittent Cylinder 1 injector
S.C. to +Batt.V.

Does that help further?

Pete

 

[Deckchair5]

Yes the descriptions help
Converting them into 4 figures codes
D600 = U1600 = key not recognised
460 = P0460= fuel level sensor
304= P0304= misfire cylnder 4
203 = P0203 = injector cylinder 3 control circuit
201 = P0201 = injector cylinder 1 control circuit

Ok
U1600 = key not recognised
could happen anytime as a one off if you are constantly struggling to start an engine but if it comes up and stays up after clearing then the engine won't be allowed to start


460 = P0460= fuel level sensor
Often happens when battery power is low and low fuel level so it senses an out of limits voltage return from this fuel quantity sensor. Clear it, recharge the battery, put some more fuel than the absolute minimum and often you'll have no problems with that item


304= P0304= misfire cylinder 4
note there is a difference between "misfire" and an ignition fault, it may not be ignition at all. Car senses that cylinder not firing or producing power on a few occasions so it could just as easily be an injector or ignition

203 = P0203 = injector cylinder 3 control circuit
201 = P0201 = injector cylinder 1 control circuit
Self explanatory

Although it may sound a little odd, reading beyond the codes, I'd check your No1 precat lambda sensor output as this will cause lumpy tickover/ misfires/loss of tickover and also the rpm sensor air gap at crank pulley may have become too large. This will cause poor starting and misfires. To get so many random cylinder misfires you need to look for something that could cause misfires on all cylinders

If you haven't got your own fault code reader then get one as it will be the best money saving investment along with a simple multimeter

 

[milleplod]

Cheers for the info!

Next questions.....'rpm sensor air gap at crank pulley'? Easy to find/fix?!

'No1 precat lambda sensor'.....where is it, and is it easy/cheap to swap for a new one?!

Pete

 

[Deckchair5]

rpm sensor
Yes easy to find, the sensor is a magnetic pick up so it needs to be close enough to sense the serrations without touching the crank pulley

Lambda sensor?
Don't change it, check it. As it's an expensive item


I'd look for oscillating voltage between approx 0.1v and 0.8v around every second at tickover like this top trace. Easier to see with a laptop diagnostics program like this but just as easy with a multimeter


Here is the front lambda sensor and its 4 wire connector. 4 wires going in, 2 of the same colour are the lambda sensor heater wires. (You can check for very low resistance there if you want to check heater continuity but car should have spotted any problem there) The other 2 wires are the Lambda sensor (also called O2 sensor).
NOTE black wire if you have one is always the signal wire and not an earth

 

[milleplod]

Thanks very much for the info.....further investigations later today!

Pete

 

[Deckchair5]

Have you had problems of non starting or running the battery down etc? The more symptoms you can give as to what's actually happening the better as fault codes are areas to investigate and not a command to replace everything in sight as some bad garages do

 

[milleplod]

No bad starting problems, ever....even when the battery started getting 'slow', it still started. The battery was around 5 years old, so perhaps well past its best when son bought the car.

Pete

 

[milleplod]

Evening all!

I managed to fix this problem, and forgot to post the remedy.....sorry!.....I thought it might be of interest as it was so simple. I went for the no. 4 cylinder ignition fault, thinking it would be a coil...bought and fitted one....didn't make any difference. Bugger. Then I went back to basics, whipped the plugs out and checked the gaps. For some mysterious reason, no. 4's gap was huge! Re-gapped it, refitted it....bingo! 'Engine fault' light gone, super-smooth tickover, no stuttering at all......

Unfortunately the gearbox went bang a couple of weeks ago....and that definitely wasn't a cheap fix!!

Pete