P1100 Fault Code

[Wazza26]

Hey PH,

Long shot - does anyone know what fault code: P1100 relates to on a Seat Ibiza MK5 (2010, 1.2ltr)?

Can't find a fault code list - and various conflicting information on the web.

Have taken our and cleaned the MAP sensor (wasn't dirty) - fault still exists. Next step is to replace the sensor...

Cheers,

J

[Hiviss]

It looks like the fault code is related to the lambda sensor heater circuit.

[Wazza26]

Hiviss said:

It looks like the fault code is related to the lambda sensor heater circuit.

Where are you reading that Hiviss?

[Belle427]

Looking it up suggests it’s a maf sensor code, are you sure you looked at the maf sensor?

[stevemcs]

Are you sure its not an air leak ?

[Wazza26]

Belle427 said:

Looking it up suggests it’s a maf sensor code, are you sure you looked at the maf sensor?

Hi Belle,

I don't believe this vehicle actually uses a MAF sensor.

[Wazza26]

stevemcs said:

Are you sure its not an air leak ?

Could possibly be an air leak - I do not have the tools to detect this, and so i may have to go into the garage for further tests.

[Gary C]

From a look at the code in wurth

P1100 OBD Code Description:

Possible causes
– Faulty HO2S12 Sensor
– Exhaust leak near HO2S12 Sensor
– HO2S12 Sensor harness is open or shorted
– HO2S12 Sensor circuit poor electrical connection

HO2S12 seems to be Heated O2 sensor. So reading its getting back is so low as to be unbelievable, the heater could have failed or the sensor itself.

Can you see the live O2 reading ?

Would that be the AZQ engine ?, how many miles has it done ?

I have one that I replaced the timing chain on and despite the cat being totally buggered, it sails through the MOT each year because it burns so well the emissions are actually ok.

Edited by Gary C on Sunday 12th January 20:46

[Wazza26]

Gary C said:

From a look at the code in wurth

P1100 OBD Code Description:

Possible causes
– Faulty HO2S12 Sensor
– Exhaust leak near HO2S12 Sensor
– HO2S12 Sensor harness is open or shorted
– HO2S12 Sensor circuit poor electrical connection

HO2S12 seems to be Heated O2 sensor. So reading its getting back is so low as to be unbelievable, the heater could have failed or the sensor itself.

Can you see the live O2 reading ?

Would that be the AZQ engine ?, how many miles has it done ?

I have one that I replaced the timing chain on and despite the cat being totally buggered, it sails through the MOT each year because it burns so well the emissions are actually ok.

Edited by Gary C on Sunday 12th January 20:46

Hi Gary,

Thanks for looking at the code in Wurth.

I'll start tomorrow by looking to see if I can see any signs of an exhaust leak. I'll also look into seeing if my OBD reader provides live O2 readings - I would suggest not as it was only cheap!

I believe the Ibiza MK5 only has two lambda sensors, bank 1 and bank 2. Does the P1100 code or 'HO2S12' give any indication as to which sensor is throwing the fault?

We had an O2 sensor replaced last year - I wonder if it's related to this.

Not sure on engine number, will check tomorrow. It's a 1.2 Petrol with 66,000 miles.

Cheers,

J

Edited by Wazza26 on Sunday 12th January 21:36

[Gary C]

if its the 3 cylinder 1.2 it will only have one bank but will have a pre and post cat O2 sensor.

Not sure how to tell if its pre or post.