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Vauxhall Corsa 1.0 Z10XEP 2007 - odd lambda voltages, multiple codes - Fixed #

Posted by Matt Seabrook on July 8, 2014, 10:47 am

Year of Manufacture *: 2007
Engine Size and Code *: 1000cc Z10XEP
( Optional ) Scanner Used: Snap-On
( Optional) Fault Codes: P2191 P0171 P0130 P0134 P0300 P2187

I'm trying to help a garage customer of mine to sort an on going fault on this Corsa.

The car came to them about a month ago and had a Lambda and fuel trim fault. So without testing anything they threw both front and rear Bosch lambda sensors on it. Then the car came back with the same fault and they then replaced the sensors with genuine sensors. All seemed well until yesterday and the car was back in with the fault codes as listed above.

I popped in to have a quick look at the car to find the short term fuel trip at max 25% and the lambda not switching and flat lined a 0V when tested in OBD live data. I scoped the sensor and found that when measured across the black (live on scope) and grey (earth on scope) the sensor was outputting -0.6volts if you gave the engine a sniff of brake cleaner to make it bog the voltage would rise to +0.15 volts and this was then shown on the OBD live data as a rise from 0-0.15volts.

I then disconnected the O2 sensor and measured the output from the sensor with the engine running and we had about 0.35-0.4 volts engine running. Give it a sniff and it went up to 0.55volts.

The fuel trim fault codes P2191 and P0171 indicate the engine management is trying to add fuel due to a very low O2 reading and the fault codes P0130 and P0134 support lambda circuit issues.

I don't think I have ever seen a lambda sensor give a negative reading before does anybody have an idea why it would do this?

Re: Vauxhall Corsa Lambda sensor odd voltages

Posted by Anthony Pickering <iframe src='https://members5.boardhost.com/ukautotalk4/info/user=ukat3715' width='330' height='300' border=0 style='border:none;'> on July 8, 2014, 12:47 pm, in reply to "Vauxhall Corsa Lambda sensor odd voltages"
Anthony Pickering

What is the voltage readings on both o2 sensor signal wires on the harness side with the o2 sensors unplugged?

also with the sensors unplugged whats the live data voltages?

have seen a blocked cat force exhaust gas into the reference chamber of a lambda sensor and that caused pre cat negative voltages but not post cat unless there is a blocked silencer.

Re: Vauxhall Corsa Lambda sensor odd voltages

Posted by Matt Seabrook <iframe src='https://members5.boardhost.com/ukautotalk4/info/user=ukat3462' width='330' height='300' border=0 style='border:none;'> on July 8, 2014, 2:54 pm, in reply to "Re: Vauxhall Corsa Lambda sensor odd voltages"
Matt Seabrook

Thanks Anthony for replying. I haven't looked at blocked exhaust yet but the map sensor is showing 290-310mb so its unlikely to be blocked. I am wondering if I am getting a voltage from the ecu which is pushing the lambda voltage down. As I said just trying to help out a good customer so not had much of a look yet but confused by the readings so far.

Re: Vauxhall Corsa Lambda sensor odd voltages

Posted by Mark Carter <iframe src='https://members5.boardhost.com/ukautotalk4/info/user=UKAT1428' width='330' height='300' border=0 style='border:none;'> on July 8, 2014, 9:47 pm, in reply to "Re: Vauxhall Corsa Lambda sensor odd voltages"
Mark Carter

What systems have been checked so far and what were the results?

Mark

Modern cars, Its all wizardry and witchcraft

Re: Vauxhall Corsa Lambda sensor odd voltages

Posted by Matt seabrook <iframe src='https://members5.boardhost.com/ukautotalk4/info/user=ukat3462' width='330' height='300' border=0 style='border:none;'> on July 8, 2014, 9:58 pm, in reply to "Re: Vauxhall Corsa Lambda sensor odd voltages"
Matt Seabrook

Sorry not with you Mark. I must be honest I called in on the garage and took a quick 20 mins look to see if I could shed any light on the problem. I will see if I can get it into my workshop to take a better look and spend some time on it. It just I don't ever remember seeing a negative voltage down the signal wire of the O2 sensor and wondered if other have come across it. I did check voltage drop across the lambda earth cable and it was less than 20mV so not expecting a problem there.

Re: Vauxhall Corsa Lambda sensor odd voltages

Posted by ray ferreday <iframe src='https://members5.boardhost.com/ukautotalk4/info/user=UKAT5108' width='330' height='300' border=0 style='border:none;'> on July 9, 2014, 7:41 am, in reply to "Re: Vauxhall Corsa Lambda sensor odd voltages"
Raymond Ferreday

p0171 is weak mixture seen garages replace oxygen sensor before and still has same problem which is generally air leak, or the old favourite air mass meter. I would clear codes and get customer to come back when the mil comes back and read fresh codes as some may be generated by people disconnecting components. ray

Re: Vauxhall Corsa Lambda sensor odd voltages

Posted by Lee mackintosh <iframe src='https://members5.boardhost.com/ukautotalk4/info/user=UKAT1348' width='330' height='300' border=0 style='border:none;'> on July 9, 2014, 8:06 am, in reply to "Re: Vauxhall Corsa Lambda sensor odd voltages"
Lee Mackintosh

Is it possible its a valve timing or chain issue as i find it strange how a dose of brake cleaner up the air intake still doesn't force the 02 sensor rich as 0.15v is still lean.

Has it got a decent afm fitted or eve nthe correct type.

Re: Vauxhall Corsa Lambda sensor odd voltages

Posted by Matt Seabrook <iframe src='https://members5.boardhost.com/ukautotalk4/info/user=ukat3462' width='330' height='300' border=0 style='border:none;'> on July 9, 2014, 8:48 am, in reply to "Re: Vauxhall Corsa Lambda sensor odd voltages"
Matt Seabrook

Hi chaps no MAF on this system just a MAP and that is reading 300 plus or minus 10mB so the running of the engine is not looking too bad. Also when codes cleared and a four gas reading is taken the readings are where I would like to see them. I know I haven't done extensive checks on the mechanical running on the car but when the system short term fuel trim is at zero after a code clear and good emissions and the 300mB of manifold vac. It's not going to be the first place I look. I need to find out why the lambda is showing less than zero volts some times as much as -0.7 volts. It's not my job really but I am treating this as a learning curve.

So just to say thanks for the help so far.

Re: Vauxhall Corsa Lambda sensor odd voltages

Posted by Mark Carter <iframe src='https://members5.boardhost.com/ukautotalk4/info/user=UKAT1428' width='330' height='300' border=0 style='border:none;'> on July 9, 2014, 9:47 pm, in reply to "Re: Vauxhall Corsa Lambda sensor odd voltages"
Mark Carter

Give me a shout when you have five.

Mark

Modern cars, Its all wizardry and witchcraft

Fixed #

Posted by Matt seabrook on July 10, 2014, 7:25 pm, in reply to "Re: Vauxhall Corsa Lambda sensor odd voltages"
Edited by board administrator July 16, 2014, 8:43 am

Right an update. I went in to the garage again today to ask if I could get the car to my workshop. They said that they didn't want to give me a headache so took it to Vauxhall yesterday. BANGS HEAD!

I got a phone call this afternoon to say that Vauxhall had taken a look at it and the oil pressure switch had failed. It had leaked oil through the switch up the wiring loom to the ECU this has damaged the ECU which will need to be replaced. Also the wiring loom needs to be changed at a cost of a grand for the loom.

The main dealer said this is the third one this week they have seen. So just a heads up to others.

Thanks for the offer of help Mark, much appreciated. Also thanks to the others for your input. My gut feeling was an ECU fault but it was getting it back to my workshop to prove it.

Re: Vauxhall Corsa Lambda sensor odd voltages **FIXED**

Posted by Anthony Pickering <iframe src='https://members5.boardhost.com/ukautotalk4/info/user=ukat3715' width='330' height='300' border=0 style='border:none;'> on July 10, 2014, 11:26 pm, in reply to "Re: Vauxhall Corsa Lambda sensor odd voltages **FIXED**"
Anthony Pickering

Glad you know what the fault is, i have seen this happen and annoyingly it slipped my mind on my post.

ones ive done ive changed the oil pressure sensor leaving the seal off so when it pops it just leaks, new lambda and wash out the ecu plugs with contact cleaner, its a pain your one damaged the ecu.

Re: Vauxhall Corsa Lambda sensor odd voltages **FIXED**

Posted by Matt Seabrook <iframe src='https://members5.boardhost.com/ukautotalk4/info/user=ukat3462' width='330' height='300' border=0 style='border:none;'> on July 11, 2014, 8:35 am, in reply to "Re: Vauxhall Corsa Lambda sensor odd voltages **FIXED**"

I must be honest Anthony I'm sceptical about needing an ECU but it's now out of my hands. It's likely to right the car off as they have been told by the dealer that the loom that is required is £1000.00 on its own.

Still it's one I will chalk up to experience and this thread may help someone ells out in the future.

Re: Vauxhall Corsa Lambda sensor odd voltages **FIXED**

Posted by Alan Ganter <iframe src='https://members5.boardhost.com/ukautotalk4/info/user=ukat3444' width='330' height='300' border=0 style='border:none;'> on July 11, 2014, 10:55 pm, in reply to "Re: Vauxhall Corsa Lambda sensor odd voltages **FIXED**"
Alan Ganter

It seems to be a common fault with them. The wiring loom (weather proofing) is so good, the oil doesent leak out, but is pushed under pressure into the ECU.

Re: Vauxhall Corsa Lambda sensor odd voltages **FIXED**

Posted by aidan birley <iframe src='https://members5.boardhost.com/ukautotalk4/info/user=UKAT2879' width='330' height='300' border=0 style='border:none;'> on July 12, 2014, 7:38 am, in reply to "Re: Vauxhall Corsa Lambda sensor odd voltages **FIXED**"
Aidan Birley

Hi

Seems to bit a issue with a few vehicles, vauxhalls in particular. Normal and obvious source appears to be be Oil switch. But have seen crank sensor as source to so watch out for that.

As to an explanation as to why it travels along wires

http://en.wikipedia.org/wiki/Capillary_action

Cheers Aidan

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