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The mkiv Supra Owners Club

MIL Light under hard acceleration


devan

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Hi,

 

Just wandering if anybody has had the MIL light come on during hard acceleration, its just started doing it tonight, after no mods to my car or anything, just random.

 

Its an n/a manual 1994.

 

I will check the codes when i get chance, but for now i just wanted to know if anybody has any experience with this.

 

Also noticed that the small light with the (!) in it also comes on, as well as the MIL, is this normal?

 

Btw the light goes off straight after my acceleration.

 

Cheers,

Ash.

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Guest suprastar380bhp

Your ECU has detected a fault if the mil (engine management light) AND the red (!) mark comes on

If it goes off straight away its ok but needs attention

But if it flashes (like an indicator) there is a serious problem

Edited by suprastar380bhp (see edit history)
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tooquicktostop: ok ill check my brake fluid levels asap,

 

dr jekyll: the first thing i did was check the handbrake was down, and the door shut, so that eliminates that, cheers anyway.

 

suprastar: Yeah the light goes off straight away, but like i said ill check for a fault code asap too.

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Sounds daft but have you had your clocks out recently.

if all the pins dont get a good connection or 1 is bend on the back of the clocks your MIL light will come on under hard acceletation. Did with mine. I had a spare set of clocks so after puting them in sorted it.

I know a few pals with supras who had this problem.

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Yeah i have had my clocks out recently, well, it was about 1 week ago.

 

I was soldering blue LED's into the indicator/hazard bulb holders on the dial cluster.

 

But i must of done about 250 miles since then, with enough hard acceleration to notice the light coming on.

 

Ill investigate the clocks if the fault code reading doesnt work.

 

Cheers.

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Right, i have a fault code 12.

 

Im assuming the table of fault codes on this forum are the same for the n.a and tt?

 

Been searching and the last time somebody had this was 2005. Apparently its the crankshaft or camshaft position sensor signal not being received by the ECU for 2 or more seconds.

 

Also noticed the red light coming on more and more now, even under normal acceleration.

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Your ECU has detected a fault if the mil (engine management light) AND the red (!) mark comes on

If it goes off straight away its ok but needs attention

But if it flashes (like an indicator) there is a serious problem

 

management light normally flashes to indicate what the trouble code is this happens when earthing a pin in the diagnostic plug for quick reference of a fault, if it stays on it has a code stored due to fault not rectifying itself, never come across a management light flashing unless its an immobilizer fault.

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Guest suprastar380bhp
Sorry I've got nothing to add, but saw 380bhp had answered so wondered what gems could be found within, loose petrol cap, I wasn't disappointed :D

 

vapour leak?

and my other two ideas emission problem? oxygen sensor

Edited by suprastar380bhp (see edit history)
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O2 sensor fault would throw up a fault code 21 (Devan are you sure you got the numbers the right way round?)

 

In the mean time I'd suggest resetting the ECU and taking it for a drive to get it to record the code again, just to verify the fault code. Fault code 12 doesn't work out since it's the crank sensor and as mentioned the car wouldn't start with a fault 12.

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Just looking though the service manual, NA's don't have a fault code 21.

 

Fault 12 is "G, NE signal curcuit No1 fault".

The distributor in the engine control system contains 3 pickup coils (G1, G2 and NE). The G1 and G2 signals inform the ECU of the standard crankshaft angle. The NE signals inform the ECU of the crankshaft angle and engine spped.

 

Fault 12 trouble area:

- open of short in NE, G circuit.

- Distributor

- Open or short in STA circuit

- ECU

 

Fault 12 lists the following checkpoints:

 

1) Check resistance of each pickup coils in the distributor

If faulty: Replace distributor

If okay:

2) Check for open or short in harness and connector between ECU and distributor

If faulty: Repair or replace harness or connector

If okay:

3) Check air gap

If faulty: Replace distributor

If okay:

4) Check and replace ECU (!!!)

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Just looking though the service manual, NA's don't have a fault code 21.

 

Fault 12 is "G, NE signal curcuit No1 fault".

The distributor in the engine control system contains 3 pickup coils (G1, G2 and NE). The G1 and G2 signals inform the ECU of the standard crankshaft angle. The NE signals inform the ECU of the crankshaft angle and engine spped.

 

Fault 12 trouble area:

- open of short in NE, G circuit.

- Distributor

- Open or short in STA circuit

- ECU

 

 

Fault 12 lists the following checkpoints:

 

1) Check resistance of each pickup coils in the distributor

If faulty: Replace distributor

If okay:

2) Check for open or short in harness and connector between ECU and distributor

If faulty: Repair or replace harness or connector

If okay:

3) Check air gap

If faulty: Replace distributor

If okay:

4) Check and replace ECU (!!!)

 

So it could still be a fault code 12.

 

My car drives perfectly, and i get a "blip" pause "blip" "blip" when i run the fault code check.

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