I can't seem to find the ECU on a TR Magna. The cover of the centre console is removed, so is the stereo and everything. I was told it'd be behind the stereo, the only thing in there is labelled a fuel processor or something like that.

The reason I need to see the ECU is because when accelerating, the check engine light is on. It only goes on for a second whenever I accelerate, then goes off again. I figure either the ECU needs replacing, or I can use the diagnostics to find out the problem, which brings me to my next question, how do you run diagnostics on a TR Magna ECU?

Also, it's dual-fuel. There are two switches, one labelled "LPG/Petrol" and the other "Primer" the primer switch is spring loaded, you flick it and it flicks back. How exactly do you use dual-fuel? Do I need to start the car, flick the primer, then change the fuel switch? It's confusing.

tcu engine module is behind the kick panel passenger foot well

and its bolted to the chassis wall

about level with the glovebox

the automatic tcu is on the floor panel under the radio

diagnostics on the ecu is near the fuse box
foot area of the driverside
its a white plug

download the free repair manual to get the codes etc

http://www.lisho.net/?page_id=3

Thanks heaps. I guess you need a cable/reader to run the diagnostics? I read that some cars just flash a code on an LED light. That's annoying.

Has anyone got any idea what my check engine light problem is? I was told that I needed to replace the ECU, but I'm not so sure.

It also idles pretty low and is a bit rough until it warms up a bit, hopefully a tune-up and oil change will get it running a bit smoother though.

Hi Plutonic,

This reply is a few days old but one way to check fault codes stored in the ECU (reported when you get the check engine light) is bu using an analog multimeter and probing the diagnostic connector pin 1 and pin 8 (cant remember which one is positive + and which one is negative - )

Set your multimeter dial to DC Volt 2.5 setting and count the sweeps of the needle and the length of each sweep.
Then just cross reference this against the fault codes shown in the service manual.
This is easier with a 2nd person writing it down as you count the needle sweeps out to him/her as you will have both your hands used holding the multimeter pins to the diagnostic connector.

I got my mum to write them down as called them out when i did mine. The system we used was i would call out "long" or "short" and she would write them down.

Please note that if more than one fault code is stored then the ECU will cycle through them one by one.
You get to see the pattern after a few cycles so you can cross reference the manual for what fault code you have stored on the ECU.

You then can go and address the fault its showing and clear the code (Clearing the fault code requires reseting the ECU by disconnecting the positive battery terminal and leaving it off for 30 seconds approx)

I hope this helps.

Helped me alot doing this as i found the cause of my trouble was a fault TPS (Throttle position sensor).
$20 for one at the wreckers and all is good since.

If your car is idling low then it could be ISC fault or TPS related.
Sometimes simple things like corrosion around the pins to the TPS and ISC cause idle issues due to the electrical connection being poor. Might be that whe nthe car wamrs up that the ISC allows more continuity through and when its cold continuity of electrical signal is weaker.

Let us know how you go.

Cheers

Hi Plutonic,

This reply is a few days old but one way to check fault codes stored in the ECU (reported when you get the check engine light) is bu using an analog multimeter and probing the diagnostic connector pin 1 and pin 8 (cant remember which one is positive + and which one is negative - )

Set your multimeter dial to DC Volt 2.5 setting and count the sweeps of the needle and the length of each sweep.
Then just cross reference this against the fault codes shown in the service manual.
This is easier with a 2nd person writing it down as you count the needle sweeps out to him/her as you will have both your hands used holding the multimeter pins to the diagnostic connector.

I got my mum to write them down as called them out when i did mine. The system we used was i would call out "long" or "short" and she would write them down.

Please note that if more than one fault code is stored then the ECU will cycle through them one by one.
You get to see the pattern after a few cycles so you can cross reference the manual for what fault code you have stored on the ECU.

You then can go and address the fault its showing and clear the code (Clearing the fault code requires reseting the ECU by disconnecting the positive battery terminal and leaving it off for 30 seconds approx)

I hope this helps.

Helped me alot doing this as i found the cause of my trouble was a fault TPS (Throttle position sensor).
$20 for one at the wreckers and all is good since.

If your car is idling low then it could be ISC fault or TPS related.
Sometimes simple things like corrosion around the pins to the TPS and ISC cause idle issues due to the electrical connection being poor. Might be that whe nthe car wamrs up that the ISC allows more continuity through and when its cold continuity of electrical signal is weaker.

Let us know how you go.

Cheers

Thanks, I heard about that, also by using a LED test light, but after going to or calling every shop in the city I can't find an LED test light. And I only have a digital multimeter. But I did call a mechanic and he said that it sounds like a problem with the TPS, so we're going to try to adjust it a bit and see if it's just set wrong and replace it if it's broken ($45 at the wreckers here). Hopefully we can fix the problem, it's more of an annoyance, I don't see it doing any real damage.

Thanks for all the info.

You can make an LED test light :) I reckon I could source the bits under $10 lol

Parts list, two led, a resistor, a pen case, brass bolt ground down to a point, a bit of wire and a clip :)