VZ 06 Computer problems

[Loopy1978]

I know this has been covered and ive read a lot on this forum about it but i thought id share my current dilemma and hopefully get some ideas as to what the problem may be. When i first purchased a second hand VZ 2006 Executive Alloytec V6 back in September it wasn't long after i got the car i had the good ol powertrain error. Anyway i used to be able to disconnect the battery and clear it and it would go away for a while then when it came back id do the same thing (sometimes turning the car off and waiting a minute it would come good also). Anyway I kept persevering with this until i had a different code come up it was an SRS Airbag fault. No matter how many times i disconnected the battery or reset the computer it wouldn't go away. So i took it to a mechanic who put it on his laptop and couldn't find any hard coded errors (probably because i kept clearing it disconnecting the battery) . Anyway he cleared it with his laptop and reset the computer and everything was fine for about 3 months until all of a sudden my LCD display on my cluster crapped itself. It slowly started to fade in and out until it finally went black and I couldn't read or see anything or tell if it was on or not because everything looked on. Read up heaps about this and everything points to replacing the cluster...right. Anyway couldn't afford that and because all my manual instruments still worked and car hadn't thrown any errors for ages i just kept driving it until i could afford a new cluster.


UNTIL i had the powertrain error come back again today. I didn't know this at first because obviously i cant read the LCD as its all black just had the normal loss of power and orange engine light come on. This happened to me on a trip and stupid me had forgotten to leave a shifter or a 10mm spanner in the car and was in middle of nowhere without being able to reset the computer how i previously did to fix the problem. So i thought stuff it ill pull the main 60 amp fuse out and reset it that way. Anyway no matter how long i waited or reset the computer this way it wouldnt go away. The error would clear but as soon as i started driving bang engine light comes back on loss of power cars obviously in safety mode. At this point getting rather frustrated as wasn't 100% sure what error was as still cant read the cluster LCD. Any pulled over again and this time without turning the car off i just ripped the 60amp main fuse out and the 60amp engine main out and car stopped. As it should. Waited about 5 minutes then plugged them back in with key still on reds and walla magical fairy dust the LCD screen on the cluster starts working again. (so much for needing a new cluster) . Anyway now i could read the LCD it told me there was an ABS Fault. So i ripped the 60 amps out again with engine running and cleared computer again. Now i have no ABS fault error coming up at all but the powertrain warning keeps coming on and cars is always in safety mode. resetting computer via battery or pulling out 60 amps doesn't get rid of it. It has fixed my LCD display though. Now im no mechanic but im a computer IT Specialist (not cars jut normal computers) and what im starting to think from all the bullshit the computer is telling me and all the faulty codes its telling me plus the LCD display being how it was and could possibly still go and coming good again im thinking that the computer is probably corrupted, screwed or dodgy??? Any Ideas would be very helpful LOL. Im at my wits end with it LOL. Oh and just to add when the problem first arose before Christmas 2014 i always had a strong smell of fuel inside the cabin. Hadnt had that at all for ages but as soon as computer started throwing powertrain error again the strong smell of fuel is back

 

[Not_An_Abba_Fan]

Limp home mode adds more fuel as well so there is no danger of leaning out the engine and damaging it.

If the ABS light came on as well as the powertrain warning, I'd be looking at the ABS module. Unplug it, clean the contacts really well and plug it back it.

Oh, and taking out the engine fuse with the key off, then turning it on for 10 seconds, then off again and replacing the fuse will also reset the PCM. But resetting it is only clearing the current error, all the codes will still be stored, plug it into a Tech 2 and see what codes actually come up.

 

[Loopy1978]

Thanks for the help. Ill have a look at tthe sensors tomorrow. And post here what i find if anything. It may be something has been bumped. Had the water pump replace recently in the last week actually so mechanic may have bumped something or something may have got drenched maybe. I had them flush the radiator also . I cleared the ABS fault earlier and it hasn't returned although power train is coming on every time i clear. The LCD screen doing what its doing is weird still. I thought it had completely crapped itself yet its working again. For how long i don't know i wont count my chickens so to speak. Ill have to take it to the mechanic for the diagnostic scanner. Dam things cost me a pretty penny since Christmas so was hoping its something i can diagnose without using the mechanics Tech 2.

 

[The1]

sounds like a bad wiring or just a dirty or loose connector somewhere, if your down this way i can plug tech2 in and check for codes/ history codes and check over it, can do software updates etc as well.

 

[Loopy1978]

Thanks for the offer The1. If i get down that way ill be sure to take you up on the offer. Much appreciated. Going over all wiring and sensors this morning to see if i can find anything out of the ordinary

 

[Loopy1978]

Ok checked all sensors and plugs. Everything seems ok. Reset PCM as Not_An_Abba_Fan suggested. Took it for a drive managed to get about 2km just normally driving (no flooring the accelerator or revving engine over 3500rpm) ran fine as it should. So i thought ill give a gut full so i floored it last 500 metres to home. i slowed down to about 30kms an hour before i floored it. As soon as it went over 4000rpm and went to change gears up towards the redline part of taco it lagged on the gear change and wammo check powertrain came back on. Also LCD screen went all black again when i started it this morning. Funny thing with that is i pull the main 60 amp out with reds on and it comes back normal (i leave key on reds when i do this). Could be something simple like a fuel filter maybe??? It is dual fuel and i only ever put about a qtr of a tank in it as i run it on gas 90% of the time so the gas module only uses fuel on start up and when tank gets low. Is gas injection also and does this automatically. The computer seems pretty screwed though. Its obvious i don't need a new cluster if i can get the screen to work. It points more to the computer though. Throwing errors for things that clearly isnt an issue. Like ABS and SRS. I mean if these were actual problems and not the computer being a corrupted piece of junk i would get the error all the time and it wouldnt go away. right?? But once ive cleared those thy never come back. Just powertrain

Correction. Reset PCM again now ABS fault is back

 

[Loopy1978]

Sorry taken a few days to get back about this problem. Im thinking The1 is right. Its faulty wiring of some sort somewhere. After the last post i made id had enough of the car so i didnt clear any errors or do anything to the car instead i let it sit there for 2 days without evening turning it to accessories or reds; I didnt touch the car at all, didnt even look at it. Anyway i decided after 2 days i needed to try and get it running properly again so i went out turned it over and magically there are now no errors at all. I took it for a spin not over revving to much on day 1 just to see if it threw an error again and it didnt. On day 2 i drove it half a dozen times again this time on 2 or 3 occasions i gave it a good flooring (only twice i red-lined it) to see if it would throw an error and it didnt. Im now on day 3 and it still hasn't thrown an error but I havent taken the car over 85kms an hour. I'm being gentle with it as my theory is once it goes into safety mode and you reset the PCM the car may need to be driven without over revving (havent really taken it over 3000rpm much) to allow it to re-synch everything properly before putting it under pressure especially if there is no real error and its just a false positive. Today I will take it for a quick spin on the freeway at 100kms an hour and see if i trigger any errors driving it how i would. Accelerating to get on freeway to merge etc. etc. Ill report back either way after i test it. Ill still take it and have it put on the Tech 2 when i can afford to take it to mechanic again. Its 2000kms off its next service anyway.

 

[Loopy1978]

Ok took it for the spin on the highway. Car has thrown no errors. I should have mentioned previous post LCD screen is all black again. The only thing i noticed with the car is it seems to be taking longer to change gears than it should. Its a 4 speed auto. Not sure if power shift is on or off because of the LCD screen. But when i was on the freeway i over took another car an floored it from about 100kms an hour and car changed into 4th at about 130kms/h. Is this normal for a 4 speed? I know a 5 speed does because my old VY acclaim had a 5 speed auto in it and always changed to 5th at 130 when i was over taking. Also when it dropped into 4th it wasnt smooth it jerked. I did notice this last few days also with it changing from 1st to 2nd to 3rd. It would jerk. Before i got all the computer errors it was changing smooth as.