Help : How do I reset the ECU ?
Thread Starter
Joined: Feb 2004
Posts: 33
From: France
Help : How do I reset the ECU ?
My Euro '99 C240 Sport Wagon seems to be in "Safety Mode" : acceleration is very poor, engine won't pull more than about 4,000rpm, etc., etc. although all else seems to be ok.
I think the ECU went into "Safety Mode" following a broken tail-light switch, which I replaced recently - thanks to this forum ! ! !
While on the subject : how can I read and/or get the "codes" out of the system ? Do I have to go to a dealer ?
Thanx a 1,000,000
Michael
I think the ECU went into "Safety Mode" following a broken tail-light switch, which I replaced recently - thanks to this forum ! ! !
While on the subject : how can I read and/or get the "codes" out of the system ? Do I have to go to a dealer ?
Thanx a 1,000,000
Michael
Joined: Dec 2003
Posts: 3,766
From: Georgia, USA
RE: Help : How do I reset the ECU ?
You need an OBDII code scanner to read fault codes and to clear them. There are some pretty cheap ones around because they're universal. Search the Web.
You can also clear the code by disconnecting and reconnecting your battery. Disconnect both cables and touch them together for 10-15 seconds before reconnecting. You won't know what the code was, but it won't matter if the ECU doesn't set the same code again. You'll need the radio code and you'll need to resync the windows. Info is in your owner's manual.
You can also clear the code by disconnecting and reconnecting your battery. Disconnect both cables and touch them together for 10-15 seconds before reconnecting. You won't know what the code was, but it won't matter if the ECU doesn't set the same code again. You'll need the radio code and you'll need to resync the windows. Info is in your owner's manual.
Joined: Jun 2005
Posts: 523
From:
RE: Help : How do I reset the ECU ?
I would only add to the process outlined by Lugnut by leaving the battery disconnected for 30 min. I once thought this was overkill, but tried 10 mins and something was screwy(don't remember what). How I knew to try it again for 30mins is beyond me, but every thing was as it should be afterwards.[sm=goodidea.gif]
Thread Starter
Joined: Feb 2004
Posts: 33
From: France
RE: Help : How do I reset the ECU ?
"Safety Mode" never happens ? Please read the Manual : there is a safety mode that kicks in when there is for example a brake-system problem (which I had - a broken stop-light switch) . In sfety mode the engine is limited in acceleration and will not rev over about 4,000rpm. It happens and it is documented in your manual.
My problem : engine starts and idles but does not accelerate at all is NOT safety mode as it is described in the manual.
Once again : engine starts and idle but does almost NOTHING when I push the accelerator pedal it will eventualy stall if I leave the pedal floored. I checked the accel cable : it is ok.
My problem : engine starts and idles but does not accelerate at all is NOT safety mode as it is described in the manual.
Once again : engine starts and idle but does almost NOTHING when I push the accelerator pedal it will eventualy stall if I leave the pedal floored. I checked the accel cable : it is ok.
RE: Help : How do I reset the ECU ?
there is a "limp home" mode or "emergency mode" for the engine and transmission i know.
but if it happens, you still can drive the car on a limited rpm. check engine light will be "on".
but if it happens, you still can drive the car on a limited rpm. check engine light will be "on".
