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[Diamond Black Geezer]

Hello.

Tried turning the key, waiting 5 seconds, then off and repeat for 30 / 50 times (must have done it 60ish times, to be sure) - I may have got this completely wrong, but that's supposed to clear the fault codes... Anyway, doing the paperclip test again, have the following...

Apologies to ask, as I have a list printed off somewhere of all fault codes, can't find the thing...

12
144
74
73
129
57
31 (standard with engine off, yes?)

Thanks in advance - just looking to see what may be next to investigate / mend before it breaks 

[Diamond Black Geezer]

Found Marks excellent guide to paperclip testing on the old site, so what I've found is...

144 No immobiliser signal
74 MAF voltage high
73 MAF voltage low
129  Exhaust Gas Recirculation (EGR) Valve Feedback Voltage Low
57   Idle Air Control Voltage Low
31 No engine RPM

I actually laughed when I saw MAF voltage high, then MAF voltage low - how both!?

So what does all this actually mean? Thanks all 

[Andy H]

Firstly - there is a theory that some historic codes will clear themselves after the engine has gone through 20 heat cycles (ie cold start - up to working temperature then allowed too cool again.) If you can make it work then let us know. Switching the ignition on and off 50 times is probably just going to wear the lock out.

Second - Is this car actually running now? or are you trying to get it to run? Most of your fault codes can be caused by unplugging the named sensor with the ignition switched on.

Third - not sure about the "No immobiliser signal" is the chip still present in the horseshoe part of the key?

[Diamond Black Geezer]

Thanks for that reply.

Nice to know I've just worn the lock out a bit more...  I read this on a forum a few weeks back, thought it was an interesting idea. It may be that it works on Vectras, or something... or as William Shakespeare once said "You can't believe everything you read on the internet"

Yes, running now. Only recently, though. Been dormant for years, and I've had all manner of things unplugged here and there, so this may well explain these 'errors'

Immobiliser chip could not be present, yes. I'll try starting it with the spare key, which has a red insert, I believe which houses the chip. The other one actually may be the original spare, without a chip, now I come to think.

So is there a reason for me to pick a MAF from the scrappy next time I'm there. Read a few days ago pre-FL ones are pretty much bulletproof..

[chrisgixer]

a fault code indicates a fault. Fix the fault. No?

[Diamond Black Geezer]

Fair point, but if I were looking at this thread and I wasn't the OP, I'd say a 'fault code' is slightly erroneously named... as mentioned, it may indicate the plug was unplugged at some point, or it's a dirty sensor, or there was a fault, but it's since been cleared. Bearing in mind that the old girl has been fired up less than a dozen times in 7 years, with plenum, leads, plugs, and ancillaries all unplugged at various points, I'd say a few if not most of these could easily be down to that. I just didn't want to actually fit a new immobiliser, MAF, EGR, and ICV (that would make it the 4th in 4 weeks) based purely on the fault codes. 

My main reason for posting was there was a 'tickticktick' noise from the rear of the engine. Not a massive worry, not after the thing wouldn't idle at all, but now that's cured, I thought I'd investigate. Couldn't see anything with a leadlight. It was only when I knocked it off did I see a tiny spark coming from an HT lead to a bracket! (I think the bracket made for the Crank sensor, not 100% sure, but a bracket, anyway) I've got a spare set of very good GM leads I can fit, but in the meantime I thought I'd just see what the fault codes said - if they made reference to 'incorrect voltage sparking plug', or words to that effect. Strangely, they don't! 

[Webby the Bear]

Is the CEL actually on? I thought it was running sweet? Although i haven't been on for long in a few days.

If no CEL and the car is running fine I wouldn't worry about it. I'm willing to bet I have a thousand codes from my engine explosion  (although that's been so long ago they've prob gone) 

[Webby the Bear]

Sorry DBG... must type faster 

 

[Andy H]

Fair point, but if I were looking at this thread and I wasn't the OP, I'd say a 'fault code' is slightly erroneously named... as mentioned, it may indicate the plug was unplugged at some point, or it's a dirty sensor, or there was a fault, but it's since been cleared. Bearing in mind that the old girl has been fired up less than a dozen times in 7 years, with plenum, leads, plugs, and ancillaries all unplugged at various points, I'd say a few if not most of these could easily be down to that. I just didn't want to actually fit a new immobiliser, MAF, EGR, and ICV (that would make it the 4th in 4 weeks) based purely on the fault codes. 

My main reason for posting was there was a 'tickticktick' noise from the rear of the engine. Not a massive worry, not after the thing wouldn't idle at all, but now that's cured, I thought I'd investigate. Couldn't see anything with a leadlight. It was only when I knocked it off did I see a tiny spark coming from an HT lead to a bracket! (I think the bracket made for the Crank sensor, not 100% sure, but a bracket, anyway) I've got a spare set of very good GM leads I can fit, but in the meantime I thought I'd just see what the fault codes said - if they made reference to 'incorrect voltage sparking plug', or words to that effect. Strangely, they don't! 

Pre facelift ECU doesn't have any way of checking for a misfire or problems with the HT side of the ignition system AFAIK (facelift does).

Because it has been standing for so long the HT leads may have deteriorated without any harm occuring to the DIS but it is quite common for faulty leads to cause breakdown of the DIS if the vehicle is driven with a misfire

[Diamond Black Geezer]

Much appreciated - even though the leads are 'good' - I decided to get some replacements sorted.

On examining the leads currently on the car, these alleged 'good' leads... the rubber is cracked, still traces of oil from when they were boiled from the camcover gasket failure, with insulating tape holding one fo them together...

  Niiice


So I'll be fitting the replacement leads, for sure 

[Diamond Black Geezer]

Is the CEL actually on? I thought it was running sweet? Although i haven't been on for long in a few days.

If no CEL and the car is running fine I wouldn't worry about it. I'm willing to bet I have a thousand codes from my engine explosion  (although that's been so long ago they've prob gone) 

Noo, no worries. Yeah, it's running sweet as a nut - perhaps a slight shudder here n there as the revs die down to a nice low idle, which may be just the ECU putting a little too little something in there, momentarily - or a misfire, of course, but no, runs lovely, without any engine vibration (aside from the fractional one mentioned above) So, now she's running nice, that means I get nice and picky - ie looking/listening for slight niggles - these being
-this slight tickticktick from the back of the engine.
-a slight wheeze/whistle from the breather bridges - I've been told it normal.
-slight, very quiet 'HSSSS...one...two...three...HSSSS' literally like a cartoon snore for the first secs of startup - sound like a vac reservoir non-return valve? That's a straw-clutching answer though, no idea, and as it goes after about 30 secs, can't ever trace it!
-Squeak from a belt or pulley

As you point out, fault codes aren't anything to get hung up on - I mean how many people regularly check their fault codes on their cars? (apart from us!) I'd wager 60% of vehicles never have a code reader plugged in their lives. Just looking out of interest, really, and if they can tell a story, you know?

[Marks DTM Calib]

Now you see a fault code does not actually tell you the fault.......a very common mistake which sadly the pro spanner twirlers appear to be unable to understand.

The ECU is telling you the symptoms it is or has seen e.g. its seen that the MAF voltage has been higher than expected and on another occasion the MAF voltage has been lower than expected......all symptoms.

As an example, the MAF voltage could have been lower than expected due to unmetered air getting in. Similarly, the MAF voltage being higher than expected might have been due to the throttle pot reporting throttle open less than it really was (just an example).

The good diag people look at fault codes as symptoms and nothing more.....the average mechanic swaps out everything related to the fault code and pisses customers off 

[Diamond Black Geezer]

Now you see a fault code does not actually tell you the fault.......a very common mistake which sadly the pro spanner twirlers appear to be unable to understand.

The ECU is telling you the symptoms it is or has seen e.g. its seen that the MAF voltage has been higher than expected and on another occasion the MAF voltage has been lower than expected......all symptoms.

As an example, the MAF voltage could have been lower than expected due to unmetered air getting in. Similarly, the MAF voltage being higher than expected might have been due to the throttle pot reporting throttle open less than it really was (just an example).

The good diag people look at fault codes as symptoms and nothing more.....the average mechanic swaps out everything related to the fault code and pisses customers off 

Approve of this!



Cheers Mark

[chrisgixer]

The assumption here is that the reason for looking for fault codes, is that there is a fault with the car that prompted the owner to look further. That is to say that the owner might think something is wrong and want more info. The codes are there to give you clues.

However if your just checking to see what might be going on from a pro active maintenance PoV then good man but the normal course of action would then be to note the codes, as you have here, and then clear them, by deleting with a code reader/tech 2/scanner thats capable of the job.

Then run the car and re check the codes in a day or so of normal running after it's been up to temp and things have settled down. Then see what codes return, then you have a good idea that the codes are recent, and not historic, from say, turning on the ignition with the engine in bits maybe to open a window to save opening the door or something soft like that.

You may then find the ecu disregards the codes your now seeing. (I don't know how that Ecu works as its the inferior pre face lift btw)

IMO get the car up and running. Go from there. If it drives ok, pulls well, no flat spots/misfires/ or stalling... Happy days, no need to worry.

If the eml stays on or it plays up, look further. Check the codes periodically, which won't hurt, and clear any remaining codes when a code Rader is to hand.

Other wise, I'd just chill tbh.

[Diamond Black Geezer]

The assumption here is that the reason for looking for fault codes, is that there is a fault with the car that prompted the owner to look further. That is to say that the owner might think something is wrong and want more info. The codes are there to give you clues.

However if your just checking to see what might be going on from a pro active maintenance PoV then good man but the normal course of action would then be to note the codes, as you have here, and then clear them, by deleting with a code reader/tech 2/scanner thats capable of the job.

Then run the car and re check the codes in a day or so of normal running after it's been up to temp and things have settled down. Then see what codes return, then you have a good idea that the codes are recent, and not historic, from say, turning on the ignition with the engine in bits maybe to open a window to save opening the door or something soft like that.

You may then find the ecu disregards the codes your now seeing. (I don't know how that Ecu works as its the superior pre face lift btw)

IMO get the car up and running. Go from there. If it drives ok, pulls well, no flat spots/misfires/ or stalling... Happy days, no need to worry.

If the eml stays on or it plays up, look further. Check the codes periodically, which won't hurt, and clear any remaining codes when a code Rader is to hand.

Other wise, I'd just chill tbh.

Good advice, cheers for that, too. Feeling very positive about things. Oh, and I amended the typo, for you