VZ no acceleration, safety mode

[ben315vz]

Hey guys,

Just thought I would post this up just in case anyone is interested or is having this problem.

Within the last 2 weeks, 3x VZ Commodores (Alloytec V6) have came into my workplace on a tow truck. And believe it or not, they all had exactly the same problem.

A warning message is displayed on the LCD screen "safety mode" (or similar). The engine wont rev up when the accelerator is depressed.

Anyway, the problem with the 3 cars was the plug on the bottom of the throttle body was broken (it would still plug in but kept sliding back off), and this happened right after the 120,000km service (when the spark plugs were changed), so when the inlet manifold was removed, the clip on the plug was damaged while unplugging it.

So in the end, we ended up buying the plugs from a wreckers (cut off a wiring loom) and re-wired another plug onto it, properly.

Just wanted to share that with everyone because it isn't too often that something like this happens and if someone has the same problem, hopefully I just saved you alot of time and money.

 

[azazeldeath]

Chances are its another mechanic ripping the plug out instead of removing it carefully. Though its good to know about.

 

[ben315vz]

Chances are its another mechanic ripping the plug out instead of removing it carefully. Though its good to know about.

Yeah the cars were serviced at another mechanic/workshop (not at Holden dealer), but I don't think all 3 cars were serviced at the same place. The clips that hold the plug in were broken, and one of them even had silastic on it (so they knew that it was broken and tried to 'fix' it).

 

[VZ5.7]

I've been having "Safety Mode" issues with my 2005 VZ SS 5.7L LS1 Manual. Long story you can look at my own post for full details if you like.
Anyway after months of break downs and with no fault codes at all to help, I went with the most common thing and replaces the fly-by-wire throttle body which contains the TPS sensor. The car ran faultlessly for about a month then the problem re-occurred... The plug on my car is fine so any other ides of what may be causing my problem??

 

[Don71]

Got the same prob did u fix your car

 

[azazeldeath]

Very old thread to bring up. But there are a couple of checks you can do quickly Don71, can you check the error codes. Even the ones displayed on the dash can be useful.

Ok to both of you now. Doing a basic check over may be helpful. Check your throttle body (Don also check your connector for the fly by wire) see if there is any buildup of oils/grim you would be surprised how much problems a sticky throttle can cause on fly by wire.

Secondly I would look at when you last changed your plugs. And fuel filter. The plugs can easily be removed on a 5.7 check the gaps and see how far off it is and the overall condition. The fuel filter can be heavily blocked and cause the same problems, if you can remove it, tap it on your hand so you are forcing the IN side to come out depending on how much crap comes out you may need to change that.

Check your oils low oil, over filled, and very thick oils can cause issues. Try unplug you MAF Sensor see if it changes how it runs, if not high chance of it being burnt out/overly dirty.

Does it sound like its running on less than 8 cylinders? If so disconnect a coil pack one by one. When you hear no change double check spark plug, test lead (swap one around) then if no change still it has a high chance of being the coil pack. Check your coolant levels and condition, if its milky you have serious problems, same goes for the oil if its milky. Has it overheated lately? Try run the car up to operating temp with the cap off and see if the coolant flows it is has overheated recently. I have encountered a lot of water pumps on both LS and Alloytecs that just perish completely (same with the thermostat).

Hard part is I am going off very little info other then safety mode (which can have alot of causes). If there was any previous problems please list them or PM them to me and I will do what I can to help.

 

[Don71]

Thanks AZAZELDEATH thanks for your help this problem has been going on for months, had 4 mechanics put scan tool on 1st said c02 sensor did that and it didn't fix problem, then scan tool said throttle body code had throttle body cleaned didn't fix it, other two times said no fault. safety mode happens when maintaining speed and gently touching accelerator specially when going down hill and just touching petal. Have had problem with electrical plug on top of motor near pulleys. also when doing very slow speed 20kms per hour or so car serges a little bit, can feel pedal moving up and down slightly under your foot turn car off and re start ok for short time then does again scan tool did give a code 2120 acelator pedal senscor

 

[Don71]

Still on this thread AZAZELDEATH

 

[azazeldeath]

First off sorry about the delay, was in the process of moving interstate and appear to have missed the previous notification.

Now there is a few things that can go wrong, and the code is actually something that the alloytecs had a problem with that required plugs being replaced on both sides of the accelerator wiring (near pedal and throttlebody). Try unplug the pedal wiring and see if there is any corrosion or wiring that feels a little off. Even spraying a little electronic contact cleaner in may help. It can also be the actual pedal sensor, as the early fly by wire models did seem to have alot of issues with it failing.

Another problem that can happen is the injectors or spark system (spark plugs, leads or coils) as much as you will hate this one remove each spark plug one by one (or number them as you remove) and check for buildups, heavy fuel smells, burn marks and the likes.

You could also have a faulty throttle body but I honestly rate its chances at low. Depending on how confident you are you can remove the plastic black case and check the contacts but there is alot of stuff in there that can move around and cause problems if your not 100% sure on what your doing.

I will state that some may not work, but due to me not having taken the car for a test drive means it is harder to tell for certain. Finally once you do any repairs disconnect your battery best overnight but even 10-15 mins will do (try flicking the headlights after it is disconnected).

 

[Don71]

Thanks mate will give it a go