The error code is lambda sensor low voltage. Basicaly I have made a post a few weeks ago about my car loosing power but no error code was recorded. Today it lost power again this time more scary than the other ones. I took it to my mechanic who had it on his expensive ECU tester and found an error code low lambda voltage. He was not sure how this could cause my power loss so he looked deeper into the history and found my engine keeps going into limp mode.
EGR valve is apparantly fine or at least no errors codeded there. The problem is now how to proceed? A new lamdba sensor is £95 trade but he isn't convinced this will solve the problem. He tried to clear the code but it keeps coming back.
So the plan so far is to buy a new lamdba sensor if this does not cure it buy a new MAF but I wondered if there was anything else other than the EGR which is worth checking?
Also just worried that I have recently put a bit of redex into the car. I put the correct mixture in and the car seems to pink a bit less (pinking has been an on going problem but it seems to be getting better with time) so I am not sure how this would affect the lamdba sensor?
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sorry to disappoint but if mechanic hasnt got facilities to check the lambda then i dispair
surely he has a 3 gasser to check customers cars prior to mot
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He hasn't looked at it properly yet it was just a quick ECU fault code check. I was only a few yards away from his garage when it happened so popped in. The problem is we don't think the lamdba will solve the power loss issue, we know its going into limp mode but there is no other error codes. It has gone into limp mode before this lamdba issue came up it seems.
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One thing you can do yourself which takes no special equipment, and costs nowt, is to trace the wiring back from your lambda sensor inch by inch, checking to make sure that it isn't rubbing and shorting against anything metal.
If the signal wire rubs against any metal, and shorts to earth, the lambda sensor voltage, as read by the ECU, will fall below the allowable range, and the trouble code will be set.
Just because the fault code has the words lambda sensor in it *does not* necessarily mean that the lambda sensor is faulty.
Fair play to the mechanic for not just saying that you need a new sensor. 9 out of 10 probably would have done!
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He hasn't charged me for this yet either. I've checked the wiring myself to the lamdba and it all looks to be in very good condition. I have also checked the emissions and it looks ok so as Bellboy says a probe test is probably needed.
I am not sure what the test quipment is but its very expensive (cost him £3k) and you have to insert a chip for each manufacturer (the software). It was when he was looking deep into the engine data logs the limp mode showed up, but interesting there is no error messages with the limp mode itself.
My question is a duff lamdba likely to cause limp mode on my specific engine X12XE?
My theory which I have just thought of is there is a rattle when I go over the bumps which I have not been able to get to the bottom of, would a damaged cat rattle in such a way? If so I suspect it could cause a phamtom C02 sensor code? Edit if the cat was blocked I guess it would also cause similar symptons to a faulty MAF hence lack of power?
Edited by Rattle on 22/06/2009 at 17:55
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>>I've checked the wiring myself to the lamdba and it all looks to be in very good condition.
Check it all very carefully. Make sure it doesn't rub anywhere. Seperate all the connectors, and make sure the terminals are clean and bright.
I have also checked the emissions
You can't check by looking, unless you have bionic eyes and can see carbon monoxide, oxygen, and gaseous hydrocarbons! - you need to test them.
>>My question is a duff lamdba likely to cause limp mode on my specific engine X12XE?
You have a lambda sensor code. You need to find why that voltage is going low. Once the ECU detects that low voltage, it reverts to a limp home setting to protect the cat. It could be the sensor itself, it could be a simple wiring fault, it could be a fuelling fault elsewhere, and the lambda is simply reporting what it measures - all of these faults could set the low voltage fault code, which could put your engine into limp home mode.
You don't, necessarily, have a "duff" lambda sensor.
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A faulty Maf sensor on these usually flags a fault with the lambda sensor.Use a genuine replacement or a similar Bosch equivalent.hth
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Just spent the last hour doing some in depth research and it seems the MAF is the most likely cause. It is probably confusing the ECU to such an extent that fuel mixture is totally out causing the C02 low voltage measurement.
At this rate I think I will end up studying a masters on engine management.
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maf sensor or the wiring to the maf sensors most common. the terminal connectors in the plug connectors become weak & vibrate causing poor connection triggering this fault. Alos make sure that if a sensor has been replaced it is with a vauxhall unit
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Just replaced the MAF myself ensuring the arrow was the right way. It seems to rev a lot faster now and it seems smoother to drive. The pinking issue seems to have gone right down as well. However when speeding up harshly from say 20 - 30 there is a tiny sputter which feels like a miss fire, I think this may be a seperate problem but as longs as the random complete power loss issue has gone I can live with a miss fire. It also seems to start a little quicker.
It will be too early to tell for sure if this problem has gone for good, too much traffic out atm, done 5 miles but its all city traffic so I could not rag it like I would need to fully test it.
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