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Surely if these were the wrong way round the pump would not run (which it does) and vag-com wouldn't show AIT?
Well its an easy thing to double check. As you can see from the thread I linked to it caused what felt like retardation to the OP and poor fuel consumption.
Quite possibly any misconnected electrical component with a resistance would provide a signal as the ecu is looking for a resistance. If its outside expectation the ecu tries to compensate.
Thanks for the thought but I was under the bonnet today as the pump started up.
You would be able to monitor this sensor via vagcom. If its as near enough at ambient to start with and increases on a run then we will have to conclude that it is connected. After all you are experiencing what others have determined as rather high inlet temps. In fact isn't that actually one measuring block you can log?
It is a bit busy in that area with connectors!
It would be a ballache (without a breakout box) but another approach would be to systematic trace each sensor back to the ecu ensuring that the sensors readings are what the ecu is seing.
You would be able to monitor this sensor via vagcom. If its as near enough at ambient to start with and increases on a run then we will have to conclude that it is connected. After all you are experiencing what others have determined as rather high inlet temps. In fact isn't that actually one measuring block you can log?
It is a bit busy in that area with connectors!
It would be a ballache (without a breakout box) but another approach would be to systematic trace each sensor back to the ecu ensuring that the sensors readings are what the ecu is seing.
Is there anyone on here with a breakout box who really knows what they're looking for?
... but another approach would be to systematic trace each sensor back to the ecu ensuring that the sensors readings are what the ecu is seeing.
Post 117:
Originally posted by UrS4boy
You don't want to go there. If you are concerned about a broken loom (BTW: OE AAN looms rarely, if ever, have an issue), use a multimeter set to Ohms and some long leads to check continunity between the engine bay device, e.g. IAT, connector and the appropriate pins in the T55 connector at the ECU.
Funny thing is either our suggestions are being criticized as being impossible/implausible or ignored because the OP doesn't want to try it (or so it seems). But yet we keep trying to suggest a solution.
Certaintly for the air temp snesor it would be relatively easy to check. I have provided a very accurate resistance at effectively room temp. Alternatively you can using the graph in Dave link, spoof a temp signal to the ecu with a known resistance and then read what it says in Vag com. If you use a resistance for say 20C and the measuring block reads 40C we know there is an issue! Its just finding something with a known resistance. I have for example used a relay to spoof a signal to a temp gauge. Have to be a bit inventive!
There is a nice VAG tool that allows you to set a variable resistance for testing various components but I have only ever seen one and it went for strong money! In this case its not necessary.
Certaintly for the air temp sensor it would be relatively easy to check. I have provided a very accurate resistance at effectively room temp. Alternatively you can using the graph in Dave link, spoof a temp signal to the ecu with a known resistance and then read what it says in Vag com.
I bet if you cold find an hot air source (hairdryer?) and a thermometer, you could soon check the resistance of the G42 IAT at various air temps. Think digital multimeter with insulated alligator clips on the IAT sensor male pins with the air directed past the PTC resistor tip of the sensor.
Funny thing is either our suggestions are being criticized as being impossible/implausible or ignored because the OP doesn't want to try it (or so it seems). But yet we keep trying to suggest a solution.
Patience Dave. It easy to type suggestions, it is harder to keep checking them out, especially when progress is difficult.
I don't know much, but I am still reading this thread willing you to find the fault, one thing that may have be tried already, but you may wish to try it again, and I only suggesting it from your recent description of the problem tonight, but consider cahnging the throttle body, the reason being that it will swop out the throttle position sensor.
Dave will post up the relevant link as he sweeps up behind me, but I recall that you may be able to use a multimeter on the TPS male pin connectors to determine its health as your move the throttle body arm. The multimeter is a start, an oscilloscope is probably ideal.
Not sure what you need to do to test the loom's female connector pins back to the ECU or wherever they go.
But physically changing the throttle body and the TPS would be useful to eliminate / re-eliminate the TPS.
It could have a faulty track inside itself that it is intermittent or heat sensitive in it's messing. There is a photo of the inside of these somewhere.
...Dave will post up the relevant link as he sweeps up behind me, but I recall that you may be able to use a multimeter on the TPS male pin connectors to determine its health as your move the throttle body arm....It could have a faulty track inside itself that it is intermittent or heat sensitive in it's messing. There is a photo of the inside of these somewhere.
Testing the F60 Closed Throttle (Idle) Switch is as follows:
Across Pins 4 and 6 on the switch:
Closed = 0 ohms (continuity)
Open throttle (slightly) = infinite ohms (open)
If either fails, adjust switch as per procedure above.
Testing the G69 Throttle Position Potentiometer:
Across Pins 1 and 2 on the switch:
Must be 1500 to 2600 ohms
Across Pins 2 and 3 on the switch:
Throttle closed = 750 to 1300 ohms
As throttle is opened from closed to WOT = increase to 3600 ohms
If NO, replace sensor.
Funny thing is either our suggestions are being criticized as being impossible/implausible or ignored because the OP doesn't want to try it (or so it seems). But yet we keep trying to suggest a solution.
Hi Dave. No. This isn't the case at all, I intend to check ALL of the wiring through to the ECU pin when I have the time this week. And the swapped plugs theory is appreciated but I watched the AIT rise in vag com and watched the run on pump start up just yesterday.
Thank you for the link, I'll measure that but I have to say, just last week I tried the one from my previous good running S6 and IT didn't alter s thing.
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