Lambda light 850 t5
 

The Lambda light came on yesterday on the motorway ,no running problems and fuel consumption is normal, it might be coincidence but i topped the oil up to max that morning , im going to have a look later at the vacuum hoses etc im wondering what are the commom causes , also will it reset itself if i fix the fault?

I changed my lambda a few weeks ago and have now had the light come on twice. Like you say, fuel consumption didn't increase on my motorway journey and the car ran fine. The ECU reported fault code 2-1-2, heated oxygen sensor signal absent or faulty. Today I took it out, it's made by Beru and put my old Bosch one back. Not tested it yet as I'm fighting a creak from the top NS suspension mount...all new parts and it creaks!

As it gets logged as a fault in the ECU you need to clear it. Depending on the age of your car it's either via the boxes behind the driver's headlight or the OBD port in the centre console.

Previously I've disconnected to reset the ECU, this doesn't get rid of the light, but supposedly clears the fuel map adaptives. Think I might just see what it does with the old sensor before resetting it.

thanks for the info , this brings me on to another question are there any reasonably priced code readers/reset tools on the market? or do i have to find a dealer to reset the light? its got the obdII in the car

Bearing in mind that it's not OBD2 standard compliant, you can do it yourself. Bobcat did a nice howto here http://www.volvo-tech.co.uk/forum/viewtopic.php?t=113

I just stick the wires in the holes and have a switch on flying leads.

Well after a trip to maplings ive made up a code reader and im getting the fault code 3-1-1 the haynes manual says vehicle speed sensor (speedometer ) signal absent . the speedo works fine and its appeared before so im not to worried.

however code 2- 1- 2 oxygen sensor faulty, also appears i cannot reset the fault and i have cleaned the connector, still no luck.

wheres the best place to get a new oxygen sensor ? and am i correct in thinking there is only one fitted? on the downpipe before the cat?

ps:thanks for the code reader link, thats saved me 50 quid straight away.

james

[QUOTE=jamie28]Well after a trip to maplings ive made up a code reader and im getting the fault code 3-1-1 the haynes manual says vehicle speed sensor (speedometer ) signal absent . the speedo works fine and its appeared before so im not to worried.

however code 2- 1- 2 oxygen sensor faulty, also appears i cannot reset the fault and i have cleaned the connector, still no luck.

wheres the best place to get a new oxygen sensor ? and am i correct in thinking there is only one fitted? on the downpipe before the cat?

also can the oxygen sensors be bench tested to confirm they have failed?


ps:thanks for the code reader link, thats saved me 50 quid straight away.

Replace only with a genuine Bosch part, use the 10 digit Bosch part number to source a correct replacement - the part no changed from the original. Search this forum the latest no. is on here somewhere.
Any Bosch agent should be able to get the part expect around £100.

re: resetting fuel/ignition/lambda light.

this can take a few goes mate, its tempromental.
when i did this recently with a phase 1 underbonnet diagnostic port that i adapted to work via the OBD II port under the coin holder... it took many attemts before realising that the after the first 5-6 second button hold down,
the light will come on after maybe two a second delay and it is when the light/audiable signal is presant that you press the button/connect wires for the second 5 seconds that actually clears the fault light and resets the fault codes.

this would not clear my "service light" but cleared lambda light and reset all engine fault codes tho.

wayne

thanks,
thats what ive beeen quoted for a bosch part, ive managed to clear the codes and the lambda light, if it comes back il replace the lambda probe.

that link does not work - does anyone have a copy that they can post?

Thanks.

BTW the engine lamp has come on (Volvo 850 T5) after a drive through some flooded rods - the water was nowhere deep enough to get into the engine - my best guess is a senor under the car got wet or some steam due to water hitting hot exhaust got drawn into the intake and confused the sensor.

I have not noticed any different in engine performance after the light came on.



just about to investigate.....