Hi all, I've seen so many forum posts about this issue but every one gives a different answer. The car involved isn't a VAG group car but the issue seems to occur in vag cars too.

 

The issue is this, one day I was driving my partners C1 and all of a sudden the tyre pressure warning light, the esc light and engine management light all come on at the same time for no apparent reason.

 

Scanned the ecu on my generic scanner and it showed a P0137 and P0139 codes. Both codes are oxygen sensor based codes. Bank 1 sensor 1 gives slow response.

 

First thing I did was put a rear oxygen sensor on and reset the light. About 30 mins into driving all 3 lights come on again.

 

Lots of other forums suggest it's a wheel sensor or a dodgy wheel bearing. But I'm not convinced. I will test the sensor tomorrow once I have the car warmed up just to eliminate it.

 

Tyre pressures are all fine.

 

Any suggestions as to what else to look out for?

 

Thanks

 

31 minutes ago, fabia_simon said:

The issue is this, one day I was driving my partners C1 and all of a sudden the tyre pressure warning light, the esc light and engine management light all come on at the same time for no apparent reason.

At a guess, based on VAG cars, either a duff battery or a weak charge. Deep load test for the battery, should be free conditional that the place that does the test gets to supply a new battery if needed. If they're present on the C1, check the alternator control wires are connected, particularly if the battery light does not illuminate on initial switch on.

Please note - I am not a mechanic or expert in anything.

 

Uhmm, how good is this scanner, is it also Citroen based.  To me, not knowing a C1 or much else really, the three lights more suggest possible wheel sensor or a dodgy wheel bearing than an oxygen sensor though of course you could have more than one issue at once.

 

Be careful with even correct error codes as often they're not the answer but just a pointer in the diagnostics.

 

Have you access to a more Citroen and/or higher level scanner to see what that comes up with.

 

Have you checked to see if the car has any updates due or recalls or stuff like that.

 

IIRC, unless I dreamed it or on Fantasy Island again Toyotas could throw up traction and engine if there was a fault at a brake light cluster and perhaps might have heard of similar with a VWSkoda (though surely not, I must be confused again).

 

If it was a VW or VWSkoda I'd also check the car battery voltage a couple of hours after the car had been parked up to make sure the battery charge wasn't low.  - now Ken's beat me to it. 😄

 

ETA: me being me if the battery was low I'd first try fully recharging the battery with an appropriate battery charger (and maintainer) and not a quick/fast charge, and see how the battery takes and holds that, possibly stand more chance as it's not a VAG car of the battery being able to be retained longer.  I've got a feeling battery chargers will get more popular over the next decade.

 

Edited 18 February, 20233 yr by nta16
ETA:

2 hours ago, fabia_simon said:

my partners C1

You might also try citroenet for C1 diagnostics. Be prepared for them to have a similarly low opinion of generic scanners to what we do.

Hi, Thanks for your responses. 

 

I've cleared the codes for now but out of interest take a look at the live data I'm getting on the O2 sensors in the videos I took. 

 

Thanks 

Please note - I am not a mechanic or expert in anything.

 

Scanners are a bit of a minefield  especially if bought off somewhere like Amazon where they might be intended more for the USA market and there are so many at different price points.  I'm not against generic scanners but some work better than others and specific systems should be better for the specific use.  Buying an all in one machine means you are obviously paying for the hardware as well as the computer programs.

 

Best to ensure you update info before every use.  I don't know how good this one is at (forget the technical term) getting the readings from the sensor(s) to the screen and gaps left, then two lots of info to screen and how in sync.  My old eyes and mind was swivelling at trying to tie up graphics and numbers on the split screen, I can only cope with both on one graph (merge graph perhaps on that scanner?).  I didn't see any battery voltage read out.

 

To me, but just about anyone else would know better than me, the display of S2 (as after cat) looks wrong, either sensor, the reading, machine's programing (doubtful here I'd have thought) or cat (or computers starved of car battery power 😁) - but check with others as I'm very often wrong.

 

Reading your OP again I see you put "Bank 1 sensor 1 gives slow response" yet you changed the rear(?) sensor.  I've no idea how it is with the C1 but sometimes although you can buy a range of sensors as replacement some are bettered suited to to particular use than others, new cheap Chinese stuff can sometime be worse than worn original parts.

 

I'm not sure how this might relate to the tyre and esc lights but I'd check the car battery voltage as if it's too low for the computers they can almost get more confused than I usually am.

 

Bit strange that the scanner doesn't show anything for the tyre and esc lights, have you looked at the wheel sensor yet, might just need a clean or check of connections and wiring.  Don't get too hooked up playing with the scanner and forget basics like visual checks and manual simple repairs (often boiling down to clean (and lube)).

 

Good luck.

 

@fabia_simon - As @nta16 implies, a fault code that says, for example, "RHF wheel sensor fault" does not mean "buy a new front wheel sensor" but "check the wiring and the rotor for breaks and/or muck or damage before spending out on a new genuine sensor".

@KenONeillwhat do you make of the videos?

 

Done some testing today and here are my results. 

Volts look extremely low on both sensors and ohms should be around 7.0?

 

Please note - I am not a mechanic or expert in anything.

 

Sorry went by this thread.  I'm not sure what you are reading there and how you're doing the readings, are you sure you've got the voltage range set correctly.  The resistance is often quoted on manufacturer's materials or parts lists, possibly on a bit of paper in or on the box, though I don't know for sensors.  You'd be much better with someone who knows electrics, a few post in Fabia Mk2 and Mk2 sections but also drift to Mk3 section sometimes.

 

Edited 20 February, 20233 yr by nta16
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