M&S again

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Originally Posted by sierrafery

My theory(might not be correct) is that it's a wrong terminology as that fault code refers to ''supply" while it's about T1+T2 return which is named ''supply" in the fault code as it's supposed to be equal with the reference feed(supplied by ECU)... the ECU is comparing the supply(delivered reference feed which is constant) with the return sum of T1 and T2 and there is a limit for the difference between T1 +T2 and the reference supply(i dont know how much) which if it's exceeded it logs that ''supply high'' fault code. I compared many logs and while it's logical that the TPS can't amplify the supply though if you have logs saved make some calculations and you'll see that T1 +T2 is always a bit greater than the reference supply and the difference grows as the pedal is more depressed... so if the voltage drop on one of the potentiometers(T1 or T2) is lower than what's normal then the sum will be higher e.g a short in one of the pots will return higher voltage then T1 +T2 exceeds that(unknown by me) limit and that "supply high" code is logged....

@worane IMO don't torment yourself with complicated measurements, better replace the TPS with a known good one cos if it's inefficient to chase other issues untill the TPS is not ruled out as it's a quite common failure.

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Hi Fery,

That is not really correct.

TPS1 and TPS2 voltages are corrected for any variation in the Supply voltage from 5000mV.
They are then added, and 5000mV subtracted from the total.
If the remainder is more than +/-450mV the "25,7 Inconsistencies Found With Driver Demand" fault is set.
There is no DD Supply Logged High (or Low) fault set in the code during this process.

The 4,7 supply fault worane reported is an error that occurs as part of Analog to Digital conversion range checking, and indicates the DD Supply voltage is above the set limit.


cheers
Paul

So stating the bloody obvious how do I rectify the problem?

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Originally Posted by worane

So stating the bloody obvious how do I rectify the problem?

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I've got no idea, but I understand your frustration.

I'm a big fan of actually diagnosing what the fault is before randomly swapping parts I must say.

That said I've got no idea...

But just for interest sake what's your battery voltage when running?

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Originally Posted by OffTrack

Hi Fery,

That is not really correct.

TPS1 and TPS2 voltages are corrected for any variation in the Supply voltage from 5000mV.
They are then added, and 5000mV subtracted from the total.
If the remainder is more than +/-450mV the "25,7 Inconsistencies Found With Driver Demand" fault is set.
There is no DD Supply Logged High (or Low) fault set in the code during this process.

The 4,7 supply fault worane reported is an error that occurs as part of Analog to Digital conversion range checking, and indicates the DD Supply voltage is above the set limit.


cheers
Paul

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I defer to you with that... thanks for explaining

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Originally Posted by worane

So stating the bloody obvious how do I rectify the problem?

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If you have a spare you should replace the TPS anyway cos i've seen cases when the driver demand related codes were not 100% accurately reported by nanocom and the fact that it's intermittent is very similar with TPS faults and these are common. IMO worth a try cos it's not a big job and at least that's ruled out... For example i've seen some driver demand fault code(not sure which one) reported by nanocom while the real problem was low fuel pressure

Quote:

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Originally Posted by sierrafery

If you have a spare you should replace the TPS anyway cos i've seen cases when the driver demand related codes were not 100% accurately reported by nanocom and the fact that it's intermittent is very similar with TPS faults and these are common. IMO worth a try cos it's not a big job and at least that's ruled out... For example i've seen some driver demand fault code(not sure which one) reported by nanocom while the real problem was low fuel pressure

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The Nanocom interprets all fault codes based on the way MSB ECU's encodes the faults.
There are some significant differences in how the NNN that relate to how the ECU hardware is configured. Adding the AAT required some shuffling of ADC sensor inputs. Fuel Temp and Coolant Temp were allocated individual inputs in MSB but are multiplexed onto a single input in the NNN. and the ECU switches between the two every 50ms. That means the Logged High / Logged Low Faults relating to ECT/FT can point to either and the Hawkeye correctly interprets this a Multiplex fault. The fault codes that identify the ECT/FT faults are marked as Invalid by Nanocom, so you'll never see.

That said, the code worane reported is correct, and that is based on identifying the points where these faults are set in the disassembled ECU code.
The 4,7 code is set during ADC range checking and relates to the internal reference // TPS Supply voltage.

Having done the throttle pedal swap before, I'd personally spend a few minutes with a multimeter checking things out before I contorted myself into the footwell for an enjoyable 30 minutes of pedal swapping. But that's just me, obviously. [bigwhistle]

worane,

Basically you need to identify the cause of the fault and then rectify.


Based on the fault code it looks like the sensor supply is being pulled high.
As I've explained above, Nanocom accurately reports this particular fault and it is specifically related to the TPS supply.

The suggests that there is an intermittent short to a higher voltage on the TPS supply.

Measuring the voltage on the TPS Supply will tell you very quickly if that is the case or not.
If it is high then you need to work out what is causing that.

The possibilities that spring to mind are:
- wiring harness problem causing shorting to a wire carrying > 5500mV.
- oil in connector
- oil contamination in the ECU

Ultimately you are the person with the car at hand, and you are the person who needs to diagnose and fix.
All we can do is make suggestions based on the information you post.

cheers
Paul

Couldn't think of it last night, but as I was sleeping it came to me...

I think I've had that same/similar issue , and it was caused by oil in the harness, so as offtrack said, I'd be checking that for sure, especially if you can verify the voltage discrepancy.
It's also a good idea to check periodically anyway, I've seen where the oil is so plentiful it actually gets into the ecu, amazing thing is the guy with the ECU said he checked, and no oil....???

That's beyond me

Cheers

Sounds very similar to the problems I had when I first bought my D2. The car would not accelerate and basically just idle. But would only do it randomly. I ended up getting another complete pedal from funnily enough Offtrack and I've had no problems ever since.
But when I was changing them out I noticed one of the nuts holding it was missing and the other one was loose. So maybe check that as well.
Cheers
Chris

Quote:

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Originally Posted by OffTrack

The 4,7 code is set during ADC range checking and relates to the internal reference // TPS Supply voltage.

Having done the throttle pedal swap before, I'd personally spend a few minutes with a multimeter checking things out before I contorted myself into the footwell for an enjoyable 30 minutes of pedal swapping. But that's just me, obviously. [bigwhistle]

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To simplify things wouldnt be better to record an inputs fuelling log on SD card from a drive when the symptom occurs? Am i wrong thinking that in this case the TPS supply live data should show that higher voltage which triggers the fault code cos being intermittent it's possible that the voltage to be OK in the very moment when it's measured with multimeter?