Heardy 0 Posted March 14, 2004 Report Share Posted March 14, 2004 Hello all, i've replaced lambda probe and i'm still getting 2 fault codes 00635 Oxygen Sensor Heating Circuit - Ahead of Catalytic Convertor 00525 P0131 O2 Sensor - Voltage Low -G39 anybody any ideas whats causing these to come up? all the wiring seems to be okay Link to post Share on other sites
zerocool 0 Posted March 14, 2004 Report Share Posted March 14, 2004 have you got the right lambda probe for the car,its not a cheapo halfords one is it?also I think there is a relay for the lambda sensor,might be worth checking that too Link to post Share on other sites
Heardy 0 Posted March 14, 2004 Author Report Share Posted March 14, 2004 I bought it from GSF it's a 4 wire universal one.When it had the old lambda probe on it came up with 00525 oxygen sensor no signal and 00635 Oxygen Sensor Heating CircuitSo i thought i'd replace it.Any ideas? Link to post Share on other sites
28v6r 0 Posted March 14, 2004 Report Share Posted March 14, 2004 The Fault Codes need to be reset once the offending part has been replaced, Have you had this done, and do the codes still come up then??Regards28v6r Link to post Share on other sites
28v6r 0 Posted March 14, 2004 Report Share Posted March 14, 2004 The Fault Codes need to be reset once the offending part has been replaced, Have you had this done, and do the codes still come up then??Regards28v6r[ Edited Sun Mar 14 2004, 01:04PM ] Link to post Share on other sites
Heardy 0 Posted March 14, 2004 Author Report Share Posted March 14, 2004 Yeah i've cleared fault codes twice now and they keep coming up!! Link to post Share on other sites
28v6r 0 Posted March 14, 2004 Report Share Posted March 14, 2004 Oooopppsss Hit the Button To Hard:-)Sawwwwyyy!Regards28v6r Link to post Share on other sites
jcorallo 0 Posted March 14, 2004 Report Share Posted March 14, 2004 The heating circuit problem could point to a relay fault. There is a relay which controls the current to the Lambda heater. VAG-COM can perform 'output tests' and Lambda heater relay is one of them. Give it a shot and you should hear it clicking under the dash once per second during the test. If in doubt, check its pushed into the socket OK and that the wiring isnt frayed anywhere, and that there is continuity from the relay panel to the Lambda socket - then last resort, replace the relay and see if that cures it. The relays are under a tenner.Cheers,Jules Link to post Share on other sites
Heardy 0 Posted March 14, 2004 Author Report Share Posted March 14, 2004 Hi jules, i havent got the registered version of VAG-COM so it wont let me do output tests.Can you tell me which relay it is or the part number as i might just replace it anyway.Cheers Jason Link to post Share on other sites
jcorallo 0 Posted March 14, 2004 Report Share Posted March 14, 2004 heyI've just been reading up on this in the Bently manual.Firstly, you should check that there is voltage getting to the plug for the Lambda probe to work.The supply plug from the car side has 4 input wires, a cluster of 3 and 1 by itself:[1][2][3][][4]You check for voltage across [1] and [2] - whilst the engine is running. You might be able to use a small bulb if you dont have a digi-meter....About the Lambda relay - the Bently calls it a "Heated Oxygen Sensor Control Module" - thats bad news for you as it doesnt sound like its just a cheap relay - its more than that.Anyway, for info, its in position 13 of the relay panel, looking from the front of the panel.[19][20][21][22][23][24][13][14][15][16][17][18][01][02][03][04][05][06][07][08][09][10][11][12]|||||||||||||||||||||| <-- fusesCheers,Jules[ Edited Sun Mar 14 2004, 05:51PM ] Link to post Share on other sites
Heardy 0 Posted March 14, 2004 Author Report Share Posted March 14, 2004 Cheers for that Jules i'll give it a go tomorow.Jason Link to post Share on other sites
Heardy 0 Posted March 14, 2004 Author Report Share Posted March 14, 2004 I've had a look in the fuse box and there is'nt a relay no 13 in there it only goes up to 12.Could it be because it's a 1997 VR6 and it's different?I'm going to check everthing else out tommorow, see if there's any power at the lambda probe.Thanks again Jason Link to post Share on other sites
Heardy 0 Posted March 15, 2004 Author Report Share Posted March 15, 2004 anbody else got any ideas it's starting to piss me off now Link to post Share on other sites
jcorallo 0 Posted March 15, 2004 Report Share Posted March 15, 2004 um - check the wiring dude!Are you sure there were no other relays stacked above the lower set of relays? They are tucked right up in the dash and are nigh on impossible to see. You might have to un-hook the relay panel and drop it down a few inches....Jules Link to post Share on other sites
Heardy 0 Posted March 15, 2004 Author Report Share Posted March 15, 2004 Wiring seem's to be okay.I tried what you said and connected the multimeter up and sometime's i was getting a reading of around 12 volts and other times the neadle on the multi meter was fluctuating up and down.Strange !! I've seen a couple of relay's above the fuse box maybe it's one of them.Thanks Again Jason Link to post Share on other sites
jcorallo 0 Posted March 15, 2004 Report Share Posted March 15, 2004 Yes - they are all above - all sort of Heath Robinson'd in there with weird clips holding them on top. Just check its all pugged in OK etc. If you do replace that control box, let me know how much it was.Jules Link to post Share on other sites
Heardy 0 Posted March 21, 2004 Author Report Share Posted March 21, 2004 I've finally cured it!I replaced it with a genuine lambda probe from VAG and guess what no more faults!!That's the last time i use cheap sensor's from GSF.Thank's for your help JCORALLO.Cheers Jason Link to post Share on other sites
jcorallo 0 Posted March 21, 2004 Report Share Posted March 21, 2004 Thank god for that! - and thanks for posting the eventual fix - too many of these posts on car forums go un-unsolved...!Riddle me this: was the GSF Lambda probe a Beru item? I bought one from ECP, it was a Beru, and there was no signal coming out of it... bit the bullet and bought a genuine Bosch item and all hunky dorey.Jules Link to post Share on other sites
Heardy 0 Posted March 22, 2004 Author Report Share Posted March 22, 2004 No it was'nt a beru i can't remember what make it was as ive thrown the box away!It's goin back though!!Where did you buy your bosch one from VAG or somewhere else i could'nt find anyone who supplied bosch one's.It cost me £53+vat by the way.Jason Link to post Share on other sites
jcorallo 0 Posted March 22, 2004 Report Share Posted March 22, 2004 I actually got it from GSF (specifically, the one in Thurrock).When ever you want Bosch stuff - get the guy on the phone to go and check the stock to see that its in a yellow box.... their computer screens dont allways show up which brand the item is....Jules Link to post Share on other sites
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