Help with fault codes!
Thread Starter
Newbie
Joined: Dec 2009
Posts: 2
Likes: 0
From: Isle of Man, UK
1991 W124 300CE 24v
Help with fault codes!
Guys,
I've got a 300CE I'm trying to return to the road after the previous owner neglected it and whilst it runs, she's definitely not healthy.
Reading the fault codes out gives me :
Current to idle control valve illogical
This sounds about right as she won't idle by herself, only with application of the right foot can I idle her at cold. When warm sometimes she'll hold idle. Where do I look for this one?
O2 sensor heating current illogical
Fried lambda sensor? I'd really rather not have to replace this if I don't have to, I'm guessing it won't be cheap?
Engine coolant sensor open circuit
I've had a look at the rear right of the block at where everyone says the sensor is located but I'm buggered if I can find it. The only temp sensor like thing I can see is at the front of the block on what I assume is the water pump.
A/C compressor short circuit
Not really high up on the list, but that sounds like something fried somewhere?
Crankshaft position sensor faulty
This is what I suspect (with the idle control valve) is causing most of my woe. Whereabouts can I find it, how hard is it to replace, and is it actually likely to be faulty or could it be corroded wiring etc.?
Any help would be hugely appreciated, I'm trying to do this on a budget and learn as I go, so taking it to my MB dealer is not an option! Ordering parts from them is though - if I have to!
I've got a 300CE I'm trying to return to the road after the previous owner neglected it and whilst it runs, she's definitely not healthy.
Reading the fault codes out gives me :
Current to idle control valve illogical
This sounds about right as she won't idle by herself, only with application of the right foot can I idle her at cold. When warm sometimes she'll hold idle. Where do I look for this one?
O2 sensor heating current illogical
Fried lambda sensor? I'd really rather not have to replace this if I don't have to, I'm guessing it won't be cheap?
Engine coolant sensor open circuit
I've had a look at the rear right of the block at where everyone says the sensor is located but I'm buggered if I can find it. The only temp sensor like thing I can see is at the front of the block on what I assume is the water pump.
A/C compressor short circuit
Not really high up on the list, but that sounds like something fried somewhere?
Crankshaft position sensor faulty
This is what I suspect (with the idle control valve) is causing most of my woe. Whereabouts can I find it, how hard is it to replace, and is it actually likely to be faulty or could it be corroded wiring etc.?
Any help would be hugely appreciated, I'm trying to do this on a budget and learn as I go, so taking it to my MB dealer is not an option! Ordering parts from them is though - if I have to!
MBWorld Fanatic!
Joined: Apr 2007
Posts: 2,381
Likes: 29
E
You can splice in an early mustang (research which year) one into the wire so you can save $60. It is ~$45 vs ~$110 for the O2 sensor.
To test the ICV use a battery and see if it "clicks". Of course first make sure there is power coming from the wire so you know its getting power.
Order your parts from either peachparts.com or autohausarizona.com. I have used autohaus for the past 2 years and they are one of the, if not the cheapest places and with free shipping over $50 it is awesome. I've had great experiences and have spent lots of money on them! Peachparts is not quite as cheap, but have a great customer service.
To test the ICV use a battery and see if it "clicks". Of course first make sure there is power coming from the wire so you know its getting power.
Order your parts from either peachparts.com or autohausarizona.com. I have used autohaus for the past 2 years and they are one of the, if not the cheapest places and with free shipping over $50 it is awesome. I've had great experiences and have spent lots of money on them! Peachparts is not quite as cheap, but have a great customer service.
Last edited by ps2cho; Jan 26, 2010 at 01:40 AM.
Thread Starter
Newbie
Joined: Dec 2009
Posts: 2
Likes: 0
From: Isle of Man, UK
1991 W124 300CE 24v
Quick update - I checked the OVP fuses and both are fine. Checked ISV with a 9V battery and can hear it clicking, so I assume that's ok?
Where can I check next? If the ECU isn't able to make the ISV work then is it something further up the line? Could the OVP be dead even if the fuses are intact?
OVP is a £20 fix from ebay, ISV is rather more expensive!!!
I also couldn't find the crankshaft position sensor at all. Does anyone have any idea whereabouts to look? Is it on the front or rear of the block?
Cheers,
Kristasn
Where can I check next? If the ECU isn't able to make the ISV work then is it something further up the line? Could the OVP be dead even if the fuses are intact?
OVP is a £20 fix from ebay, ISV is rather more expensive!!!
I also couldn't find the crankshaft position sensor at all. Does anyone have any idea whereabouts to look? Is it on the front or rear of the block?
Cheers,
Kristasn
