I have a 2004 Mitsubishi Carisma 1.9 Turbo Diesel
Where is the ecu?
I've looked in the engine bay,under the dash and removed the centre console.
Have i missed the obvious? (probably!)
Hope someone has some ideas :)
Edited by Pugugly {P} on 19/10/2007 at 21:18
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Norman
A 1.9TD on an '04 plate?? I thought that the DI-D [DCi] unit replaced that one in '01?
On the 1.9TD it should be in the centre console - not much of an ECU; it's only a Lucas rotary pump with a tack-on timing solenoid.
Why do you want to access it?
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Sorry Screwloose. It is a 1.9 D-ID.
Been to Mitsu dealer. Engine check lamp comes on but no faults stored. Thought about getting it tested but i cant find it.
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Norman
Yep; it's a Renault DCi unit all right - the famous "No fault found" even with the light coming on. Was the light actually on when they tried to read it?
ECU failure is very rare; the EGR valves are the most common problem on the DCi's.
To find the ECU; follow the engine wiring harness away from the engine. With around 80 wires going to it, it's loom will be quite chunky. Usually somewhere in the engine bay on DCi's - it may be protected with a steel security plate.
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Its had a new egr recently-no difference.
The light wasn't on.
It comes on when starting the car and pressing the clutch pedal turns it off!
Its had a new clutch switch twice and wiring checked,all to no avail.
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Norman
The clutch switch can affect the function of the accelerator pedal position sensor.
Might be worth cleaning the contacts on the APP sensor with contact cleaner.
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Do i have to unscrew the pedal to clean the contacts?
Is the accelerator pedal and sensor all one piece?
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Norman
Never done one, you'll have to eyeball it; my experience is - inevitably - based on this engine in the myriad of Renaults that it inhabits.
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I Will have a go this weekend and let you know how i get on.
Many thanks for your pearls of wisdom.
Kind regards, Norman.
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Have cleaned app as suggested-not very dirty inside and rechecked brake switch and clutch switch at the same time.
Started the car this morning and guess what-the light was back on, except this time when increased the revs above idle the light went out by itself!
Any other ideas.
Some have suggested the battery (1 year old)
Others thought the Air mass meter was at fault (no faults registered)
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Norman
Just had an idea about that light on and no codes. This could just conceivably have EOBD generic self-diagnosis as well as the manufacturer-specific one. [Diesels were adding EOBD at around this year.]
Maybe your dealer read their side of the system as normal; but didn't check to see if the code was stored in the EOBD side?
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Had a further poke around under the dash. The wiring connector that plugs into the brake pedal switch was very loose.
Could this affect the clutch pedal switch with the consequential Check Engine Lamp coming on?
The brake pedal switch has four wires going into it.
The car has cruise control and Abs fitted.
Any thoughts?
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Watched the main dealer plug their diagnostic MUT-11 into the same port as i used to read the fault codes. Nothing was showing.
Is it possible that because the check engine light comes on in cold weather, and the output available from the battery is lower that a voltage drop (because the glowplugs and water heater plugs are on) could trigger a false alarm with sensors?
Put a voltmeter on the battery and before starting it dips to 11.9 volts then steadies to 12.2 volts.(cold weather)
In warm weather it dips to 12.1 then up to 12.5 volts.
Could i be onto something or is this a red herring
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Norman
Yes; that a definite possibility - although a low supply voltage code will normally persist.
Maybe the battery is starting to weaken?
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Sound like your battery is not getting its full charge.
With the engine on, across the terminals the battery should be reading over 13 volts - more like 13.7V.
It could well be that there is a poor earth somewhere on the alternator so that upon spinning the engine, the voltage drops enough to cause the EOBD light to come on.
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Battery weakening at 1 year old? Fairly unlikely, unless it has been undercharged for a long time.
Could be a bad earth to or from the starter.
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Check Engine light comes on in cold weather when starting from cold.
Pressing the clutch pedal turns off the light
No faults found when ecu read by Mitsubishi Main Dealer.
3 Weeks and with temperatures as low as -2 degrees C, the light hasn't come back on.
It seems that the glowplugs coming on caused a voltage drop
When starting the engine the Bosch ECU was detecting faults that existed temporarily (and cleared when voltage increased to 14 volts)
To fix this:
1.Turn on ignition (lights on dash on)
2.Press clutch pedal down
3.Wait for glowplug light to go out
4.Start engine
Sounds simple and it works.
May work for other cars that use Bosch EDC 15c3 ECU (i gather there are a few)
Thanks to Screwloose and Red Baron for their help.
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Norman
To flag a low supply voltage code the ECU would have to see below 9 volts across it's feed and earths.
I'd go with Red's idea and check the feed and the volt drop between the ECU earth and the battery neg. This is a very unusual fault. [But then; it is French...]
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