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MG MGF Technical - Question re: signal from oil temp sensor

I am installing a new, non-OEM digital oil temperature gauge. It comes with its own sensor and a multi-joint for keeping the old sensor in place.

I am going to wire up the new gauge to the new sensor, but wondered what to do about the OEM gauge etc. I know the oil temp sensor sends data to the ECU for fuelling purposes, but can I just disconnect the wires which run to the old gauge, and cap them off, or will this somehow affect the signal to the ECU?

I assuem the signal has been ent to the ECu before it gets to the gauge?

Thanks in advance

I Brown

Oil temp sensor is just for the gauge :o)

Which after market gauge are you fitting?
Rob Bell

Thanks Rob.

Does that mean I can just use the wires from the OEM plug to connect to the new gauge, to save ruinning new wires through?

Its a McGill motorsports LED gauge. I got fed up with malfunctioning clocks so, replaced clock with a voltmeter, in smoked black glass. Then had to get new oil gauge to match ;)

Here is pic of gauge,

and here is a video of my voltmeter gauge in action (in bright sunshine so not doing it justice), oil gauge is the same more or less.
I Brown

Shouldn't be a problem - see the electrical diagram on Dieter's web page:

Cool looking gauges BTW - only around 20 quid?
Rob Bell

Thanks again Rob. Yes around 20 quid...cheaper than most other gauges, especially LED types.

So from wiring diagram , the oil temp sensor just goes straight to the gauge, as you said, but in the workshop manual it says

"The engine oil temperature sensor is located in the oil filter housing on MPi engines and in the Hydraulic Control Unit (HCU) on VVC engines. The sensor provides a signal which allows the ECM to adjust fuelling values according to engine oil temperature, to produce optimum engine performance and minimum emissions during the engine warm up phase."

suggesting the ECU must get a signal from the sensor? Now I am confused
I Brown

Well that is certainly very confusing. I know that the VVC has an oil temperature sensor that has an output to the engine management system for exactly the function described above - but I am unsure as to whether the one for the gauge is separate on MEMS2J cars (?), and I don't think that it applies to the MPi.

For a more detailed break down of MEMS2J sensor inputs, see Tom White's Caterham seven pages -

Of course, I could be wrong! But I don't think so - especially if you look at the MEMS wiring schematics. Oil temperature is included on the MEMS2J system - but not the MEMS1.9

So no problem if yours is an MPi - but on a VVC, I am not sure whether there is just the one oil temp sensor - or two?
Rob Bell

This thread was discussed between 12/08/2010 and 08/09/2010

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