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[SIR Philbutt]

Apologies for this being a bit long but looking for suggestions that I have not already done

As above - have been getting this error when spanner light comes on, although light not on permanently, it resets with ignition off/restart.

P1555   Throttle Position Sensor (TPS) Load Signal not Plausible with Engine Load

Happens when cold and hot, town and motorway, petrol and LPG.
The only occasion I can make it happen consistently is when parked up and holding the revs between 1500 - 2500, occurs almost instantly.

The car drives normally, at all times.
Revs do not fluctuate when idling.
Fuel consumption seems usual
When started cold the revs are 1100ish and come down to 800ish after a couple of minutes

Have researched on here and t'internet and consensus is clean throttle body & unblock hole and breather pipes - did this, no fix
Other suggestions include,
replace throttle body & gasket - done that
replace cam sensor - done that
replace lamba's - done that
have also,
replaced MAF and air filter.
EGR blanked and un-blanked
I am getting desperate and trying anything

Some history, in done order, to fix numerous other problems
New Silencer - padding blown out
New CAT flexi - blowing
New CAT back boxes - rusted
New EGR gasket - leaking
New exhaust manifold - cracked

Cannot recall when code first appeared but was definitely there when I was investigating the EGR gasket problem

Did suspect throttle, but discounted it when discovered the error occurred when using cruise control
Also have considered ECU, but assumed I would be getting other problems as well

Completely stuck now can anyone suggest where to look now ?

TIA
Phil

[SIR Philbutt]

forgot to mention

The EML (engine light) has been on once, for a couple of days, and the spanner light did not come on during this time ?

[4x4]

Did you change tps when you changed throttle body?

[SIR Philbutt]

Did you change tps when you changed throttle body?

It's part of the TB 

[RobG]

Did you change tps when you changed throttle body?

It's part of the TB 

Another TPS above accelerator pedal

[SIR Philbutt]

Did you change tps when you changed throttle body?

It's part of the TB 

Another TPS above accelerator pedal

Does it happening when using cruise only exclude the accelerator (stop, reset, set off, engage cruise, short dist - error, repeat, error again)

[RobG]

Does it happening when using cruise only exclude the accelerator

Nope. When using cruise, accelerator is still "in play"

[Andy B]

Does it happening when using cruise only exclude the accelerator

Nope. When using cruise, accelerator is still "in play"

how? The 2.2 is fly by wire 

[RobG]

how? The 2.2 is fly by wire

Still uses the pedal to accelerate (hence 2nd TPS at top of pedal), doesn`t go faster by magic Andy

[TheBoy]

Without live data, we're pissing in the wind. And the random part swapping may cloud it futher.

But I'd be looking for air leaks, or comparing MAF values with known good

[Andy B]

how? The 2.2 is fly by wire

Still uses the pedal to accelerate (hence 2nd TPS at top of pedal), doesn`t go faster by magic Andy

I'd have thought that the magical engine ECU would accelerate without the pedal ..... 

[RobG]

how? The 2.2 is fly by wire

Still uses the pedal to accelerate (hence 2nd TPS at top of pedal), doesn`t go faster by magic Andy

I'd have thought that the magical engine ECU would accelerate without the pedal ..... 

As long as it gets a signal from TPS which is attached to the pedal via a double-ended balljoint linkage. The TPS when receiving said signal actuates the throttle pedal

[Andy B]

Sounds about right when you think about it, otherwise the pedal would return to 'zero' when you selected cruise & you removed your foot from the throttle. 

Funny that you should have a picture 

[RobG]

Sounds about right when you think about it, otherwise the pedal would return to 'zero' when you selected cruise & you removed your foot from the throttle. 

Funny that you should have a picture

What a surprise

[SIR Philbutt]

how? The 2.2 is fly by wire

Still uses the pedal to accelerate (hence 2nd TPS at top of pedal), doesn`t go faster by magic Andy

I'd have thought that the magical engine ECU would accelerate without the pedal ..... 

As long as it gets a signal from TPS which is attached to the pedal via a double-ended balljoint linkage. The TPS when receiving said signal actuates the throttle pedal

So first suggestion is the throttle pedal - I did suspect this but made the wrong assumption about cruise - thanks Rob/Andy

Without live data, we're pissing in the wind. And the random part swapping may cloud it futher.

But I'd be looking for air leaks, or comparing MAF values with known good

Not exactly "random" TB, just a progression of the most suggested solutions, gleamed from here, to the more obscure as not getting any resolution.

Been all over it, like a car bonnet, looking for leaks, originally when I had the EGR gasket leak and again with this. Not found any. Wouldn't a leak be causing some other "symptoms"? If you can suggest a leak source that can cause just a P1555 error and nothing else then I would gladly test it, got used to the different flavours you get when sucking and blowing an Omega. Cue STMO 

Difficult to use a known good MAF, no one seems to have a spare. I have purchased a GM one to at least have some confidence in it's operation and it made no difference. So either they both have the same fault or the fault is somewhere else.

Is there somewhere on here a set of known good live data that i could compare with, if Mr Beanz is finished with his Autel and kindly lets me borrow it again.

Oh and used to P1555ing in the wind for weeks now