Hi all. For about 6 months now the engine check light in the dash has been on / off intermittently and I've no idea as to the cause.
It's never on during the very first few seconds of engine running, and after that it's on roughly 75% of the time and starts to turn off if the engine gets really warm (but not always).
Because it's never on until the engine runs, jumping the pins on the diagnostic port yields no error codes (I assume this can only be done with the engine off?).
Any ideas? Thanks
Intermittent engine light
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Re: Intermittent engine light
Could be lambda related?
Re: Intermittent engine light
So to confirm, when you put it in diagnostic mode the engine light just flashes at you at a regular interval, indicating no codes stored?
How is the car running otherwise?
How is the car running otherwise?
Re: Intermittent engine light
SonicSW20 wrote:So to confirm, when you put it in diagnostic mode the engine light just flashes at you at a regular interval, indicating no codes stored?
How is the car running otherwise?
Yep exactly. Car seems to be running fine!
Re: Intermittent engine light
I have the exact same issue. Orange engine light comes on when car starts to warm up.
Re: Intermittent engine light
Check ECU for leaking capacitors. I had same problem until I replaced them.
Thanks
Thanks
Re: Intermittent engine light
Baldurbus wrote:Check ECU for leaking capacitors. I had same problem until I replaced them.
Thanks
^^ i had the same problem but my car was bucking and coughing too. new ECU fixed the problem.
Re: Intermittent engine light
Draven wrote:Baldurbus wrote:Check ECU for leaking capacitors. I had same problem until I replaced them.
Thanks
^^ i had the same problem but my car was bucking and coughing too. new ECU fixed the problem.
Do you still have a old ECU?
Thanks
Re: Intermittent engine light
Baldurbus wrote:Draven wrote:Baldurbus wrote:Check ECU for leaking capacitors. I had same problem until I replaced them.
Thanks
^^ i had the same problem but my car was bucking and coughing too. new ECU fixed the problem.
Do you still have a old ECU?
Thanks
That was many years ago, car gone with all parts.
Re: Intermittent engine light
Hi guys, unfortunately this is still happening
Something I've discovered today though, is it's related to the pump relay. Basically if I start the engine, after idling for 10-20 seconds, just as the engine is almost fully settled, the engine check light will turn on, and at exactly the same time, the fuel pump relay switches (I can feel it click).
Any ideas?
Something I've discovered today though, is it's related to the pump relay. Basically if I start the engine, after idling for 10-20 seconds, just as the engine is almost fully settled, the engine check light will turn on, and at exactly the same time, the fuel pump relay switches (I can feel it click).
Any ideas?
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Re: Intermittent engine light
Having the same issue,
Turn ignition on, dash lights up, fuel pump can be heard running, start engine ECU light stays on.
Car seems to drive fine, but have been reluctant to take it out.
It did go out after a 15min drive to work but can back on for the journey home.
Funnily enough I can get the ecu light to flash when using the paper clip diagnostic tool.
Turn ignition on, dash lights up, fuel pump can be heard running, start engine ECU light stays on.
Car seems to drive fine, but have been reluctant to take it out.
It did go out after a 15min drive to work but can back on for the journey home.
Funnily enough I can get the ecu light to flash when using the paper clip diagnostic tool.
Re: Intermittent engine light
Yeah if I do the paperclip test it just flashes normally
Re: Intermittent engine light
What happens if you let it idle in diag mode? I am not sure exactly how the code reading works on an MR2, but perhaps it'll flash something at you if the fault occurs while in this state?
Re: Intermittent engine light
I tried that, basically the engine light flashes constantly at first, and then the light turns solid (matching it turning on when not in diag mode). It doesn't throw up a code
Weirdly if I remove the paperclip with it running and reinsert it again, the engine rpm picks up for a few seconds then bogs right down to 600rpm or so. I guess the diag mode is only for when the engine is off because it seems to mess with the fuel mix or something.
Weirdly if I remove the paperclip with it running and reinsert it again, the engine rpm picks up for a few seconds then bogs right down to 600rpm or so. I guess the diag mode is only for when the engine is off because it seems to mess with the fuel mix or something.
Re: Intermittent engine light
Are there any non-critical relays I could swap out with the fuel one to see if that makes any difference?
Re: Intermittent engine light
I've replaced the o2 sensor, still no luck: https://youtu.be/bB7t4IqJtp0
More: https://www.youtube.com/watch?v=EPV8AyRSgxQ
More: https://www.youtube.com/watch?v=EPV8AyRSgxQ
Re: Intermittent engine light
DaveWS wrote:I tried that, basically the engine light flashes constantly at first, and then the light turns solid (matching it turning on when not in diag mode). It doesn't throw up a code
Weirdly if I remove the paperclip with it running and reinsert it again, the engine rpm picks up for a few seconds then bogs right down to 600rpm or so. I guess the diag mode is only for when the engine is off because it seems to mess with the fuel mix or something.
Diag mode is used to set ignition timing, it puts the timing into static mode so a drop in RPM is normal.
Clutching at straws really... Have you removed the ECU and taken the cover off to inspect the board? They're at that age where capacitors fail which can cause all sorts of odd issues.
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Re: Intermittent engine light
DaveWS wrote:Yeah if I do the paperclip test it just flashes normally
If I do the paper clip in the port the Light stays lit and doesn't flash at all.
I'm thinking ECU fault.
Might throw a video on YouTube for comparison.
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Re: Intermittent engine light
Draven wrote:Baldurbus wrote:Check ECU for leaking capacitors. I had same problem until I replaced them.
Thanks
^^ i had the same problem but my car was bucking and coughing too. new ECU fixed the problem.
Was the coughing and bucking present at any particular instance.
Mine coughs and bucks in 4th or 5th under slight load
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Re: Intermittent engine light
Just pulled the ECU and found a leaking capacitor C512 it's a 10mf 50v.