'CHECK DRIVETRAIN' VZ 2005 3.6l Alloytec analysis

[Skipper2017]

I have a 2005 VZ Commodore with a 3.6l 175kw Alloytec engine that is now showing the 'check drivetrain' warning on the dash. There is no obvious power drop, rough idling or high fuel use, yet! After some investigation it seems most likely due to an o2 sensor. Now I havent looked under the bonnet yet but I'm getting conflicting info on how many sensors there are on the car and what type they may be. This came from trying to purchase a couple. It appears there can be a couple of different connections with either 4 or 5 pin plugs and also whether there are 2 precat and 2 post cat in total or just 2 precat! Also their exact location although I'm inclined to guess one on either exhaust outlet up near the manifold. Guys can you please clear this up for me so I dont make the wrong purchase. Oh and why I havent looked under the bonnet yet is because the car is left in a carpark because I have to catch a further means of transport to get to and from home, ie ferry.

 

[timmy201]

The check powertrain message could be anything. You'd be better off getting the codes checked before spending any money on unnecessary parts. My car had the powertrain warning, and it turned out to be a faulty oil pressure switch (and it ran perfectly fine).

 

[greenacc]

There will be 4 O2 sensors, 2 pre and 2 post cat as you said. The pre cat are likely 5 wire ones with square plugs but don't go and waste $450 buying a set based on a wild guess. Also make sure you've got a good set of tools and Ramps to work under or you'll never get the pre cats out.
AFIaustralia website will show you which ones would fit. Go to buy online as guest...

 

[rambunctious]

Best way you can find out.
Get a scanner and scan the car, or have it scanned by someone who knows what they are doing.

Meanwhile you can still drive the car, and when scanned, if it shows up oil pressure switch, make sure you get the right one, best to go to either Bursons or Holden.
Repco sold me the wrong one.

I borrowed a scanner form neighbour(under $100 on ebay he tells me)
and mine scanned up "hot O2 sensor bank 1 sensor 2" for memory, which is drivers side, and second sensor near rear of gearbox.
I then gave my VIN to local Holden dealer who got the correct sensor.

Hardest job was getting my hand up over the rear cross member to undo the wiring clip, other than that, they are not hard to change over, and they don't need to be extremely tight as they have an aluminium compression washer to do the sealing.

Many have said we should replace all sensors just like plugs and coils, but so far I have got away with changing just the one.

The 2 you refer to as precat you can see if you lift the bonnet.
Drivers side would be the hardest to get to because of the steering.
The other 2 are near the rear of the gearbox.

 

[rcsv6]

I had o2 fault codes and it was the passengers side precat sensor on my 05 sv6 because the wires were touching the exhaust manifold and had melted through the insulation and have had no problems since and I made sure new wires were secured away from exhaust manifold.

 

[Skipper2017]

thanks everyone for the info, suppose the best course is to have the fault scanned first

 

[Skipper2017]

thanks everyone for the info, suppose the best course is to have the fault scanned first

I just posted re scanner cables and software but I have a question... as the o2 sensors feed data back to the ecu on fuel/air mixture is it possible that a dirty air cleaner could also cause this warning to appear on the dash if the airflow was restricted in any way? just thinking

 

[greenacc]

It could throw a code if there was a major blockage or dirty sensor eg MAF. Not just the average dirty air filter.

 

[cockney rebel]

I have a 2005 VZ Commodore with a 3.6l 175kw Alloytec engine that is now showing the 'check drivetrain' warning on the dash. There is no obvious power drop, rough idling or high fuel use, yet! After some investigation it seems most likely due to an o2 sensor. Now I havent looked under the bonnet yet but I'm getting conflicting info on how many sensors there are on the car and what type they may be. This came from trying to purchase a couple. It appears there can be a couple of different connections with either 4 or 5 pin plugs and also whether there are 2 precat and 2 post cat in total or just 2 precat! Also their exact location although I'm inclined to guess one on either exhaust outlet up near the manifold. Guys can you please clear this up for me so I dont make the wrong purchase. Oh and why I havent looked under the bonnet yet is because the car is left in a carpark because I have to catch a further means of transport to get to and from home, ie ferry.

drivetrain warning lights are designed to give you ADVANCED warning of any fault, so you can still drive. 90% of faults are minor, but, if you dont check what they are, they can become major. mechanics i have heard of, are charging, between $90 - $140, to check and erase, fixing is extra. getting your own scan tool will save you heaps in diagnostic fees, and most faults CAN be fixed by the home mechanic. after a lot of checking around on the net, i just bought the, AUTEL AUTOLINK AL519, $100. works great, i checked my 2 fault codes, created one of my own by removing a sensor lead, while the scanner was connected and engine running, fixed the problems, erased the codes, and after, drove a ' DRIVE CYCLE ', to check all was fixed, this is in the instruction book. you will have to read the instruction book several times, and practice with the scanner, before you understand how to use it, after which, you will never worry about a 'check drivetrain' light again. now you have a new toy.

 

[MartinJS]

My Check Powertrain light came on the other morning, car runs a bit rough on cool/cold start up other than that drives fantastic and once warm runs smooth as, can hardly hear it!
Looks like I'll be getting a scan tool soon! Also have the service vehicle soon message, maybe an oil senors issue as some seem to say both can be linked to faulty oil sensor!

Got the car fully service and checked only a month ago so am guessing sensor issue.
Good info peoples.