Hilux limp mode issue

You do know that if there is a fault the nothing short of fixing it will clear the code? Scangauge will also only give you the code. It is up to the user to have a list of what the codes mean.

That’s stating the obvious or so I thought.

Once you've got the code try this


Regards

Thanks for those suggestions RMD. I had already checked the earth at the battery terminal, but maybe there's another lose connection somewhere.
Yes lots of cruising on light throttle over the years as it has a diesel-gas system installed. And before you suggest this may be the problem, I have the same problem with the gas turned off and running straight diesel.
I'll pass on your comments to a diesel mechanic when I find one in Perth.
Any recommendations for a mechanic by you Perthies out there?
Cheers,
Shep

Shep
I didn't mean the battery terminal, it is the most unlikely to be the problem as it passes enough current to start. It is likely to be a body earth which has been bolted to the cabin sheetmetal, either inside or outside the cab and is an earth for the systems. There are a few of them, some singles and some multiple eyes which could be firmly bolted to a nice paint underside and vibes make it not touch sometimes.
I know of Nissan Navaras which has similar problems and until it was accidently found by removing the bolt and cleaning to make a good contact, when it happened the vehicle just stopped dead. No start. All the injectors earth to negative somewhere and their connection to negative has to be good. If done through the ECU it's neg connection must also be correct.
Look for any wiring to earth/negative and check the integrity of the connection. If you find a loose one then rattling will make it intermittent.
Such a fault may show a code but not indicate where or what.

Sounds like I need to find someone to devote some serious time to exploring all these connections both under the bonnet and from under a hoist.
Thanks again for your thoughts RMD.

No chip, but thanks for your sugg William.

Pop
If you have a list of the codes, it will point to a fault in that system.
The Scangauge or similar only displays the info stored in the ECU memory.
All good if the fault is a component or sensor, but if it is an itermittent connection type fault the ECU may not record anything as wrong or more importantly it may indicate many sensors are at fault.

My local Nissan dealer had a Navara which indicated multiple sensor faults all at the same time, in a near new vehicle which stopped and would not start. After fiddling with wiring and negative earthing points it was then perfectly OK and indicated NO Faults present after they were initially cleared.
The unfortunate thing is, the owner then wanted to trade it in for another vehicle and was told the dealership wouldn't trade it because it had faults. The faults never happened again. He bought a different brand of vehicle, disgusted with that previous brand.

I purchased a portable OB2 reader kingchrome from memory.

Bit hard to remove a ahrd wired unit to assess code fault on another vehicle

in the booklet of "how to use it" is a comprehensive list of commonly used codes

starts at: P0001 fuel volume regulator control circuit open

ends at P0999 shift solenoid F control circuit High

and a plethora of others in between -hard part what happens if manufacturers use more than 999 errors in the future

RMD,

If my memory serves me, each sensor and it's associated wiring, plugs and connection points worked on a supply voltage commonly around 5v + -. There was then an operating "window" to supply the ECU information that it considered along with other inputs and compared to it's "mapping" for want of a better description.
Any reading above or below it's set parameters resulted in a fault code being generated. This code was then stored for later retrieval by some form of hard/software such as a Scangauge. To interpret the code or codes you obviously needed a list which translated into language the technician could work with.
The software we were provided as a dealer for the particular piece of equipment we were dealing with, American in origin in our case, came with the interpretation of the various fault codes and a possible "follow the bouncing ball" series of suggestions to find and correct.
All good if you had the interpretation of the various codes. Pretty meaningless for the average bear if you didn't.
I am not familiar with the Scangauges and what info they may provide other than a list of Pxxxx numbers.
Do they give interpretations such as "throttle position sensor voltage high/low" ??

Cheers
Pop

Pop
I think all you get is the P code number, the rest you work out by having other info.
When my boost chamber hose fell off, it only gave a code of low boost, I had to find why.

RMD,

I guess in your situation you knew, or were able to ascertain, that the code number thrown up by the vehicle in question indicated a low boost situation. My point being that without that knowledge, it's just a number.

We were also given the resistance values across the pins of each sensor and the values at the ECU so that we could isolate a sensor fault or a wiring harness fault.
To carry out these test all that was needed was a multi meter.

One of the first items we were always instructed to test for was that the vehicle had a fully charged battery and supply voltage to the ECU before starting any diagnostic procedures.
It's amazing how many so called techs I came across who failed to check that very basic first step.

Cheers
Pop

John.
That doesn't give any help as to what Shep's problem may be. Going to a service centre where they scan it and hopefully Identify and correct the problem is available to anyone. Not much help when out on the road though. Some background possibles are uselful to check. He may then be able to correct it himself at no cost or greatly reduced cost.

Having a problem and only seeing a signpost isn't going to fix it.

RMD

True. However I was only replying to the last paragraph of the original post.

Cheers
John

This is a late follow-up to let everyone know that the problem has been fixed.
John Dougherty of Port Kennedy Automotive Repairs 08 9524 6777 changed the Acceleration Assembly which is the module attached to the accelerator pedal and sends the drive-by-wire signal.
John was able to nail the problem after interpreting the scan code and drawing on his experience to pinpoint the issue; it was far from straight forward and I'd have no hesitation in recommending this switched on mechanic to forumites.
Thanks again to the above forum contributors who took the time to help me.
Cheers, Shep