Auris P2915 (A/F Sensor Stuck Lean)

[aricooperdavis]

Hi folks!

This is my first post but I've lurked for a while for other issues, so thanks to the amazing community!

I have a 59 plate 1.33 petrol Auris (NRE150) with 103k miles that is giving a check engine light for P2195.

In my haste for a quick fix I took it to an independent garage who "replaced the lambda probe" and gave it the all clear, but the check engine light has come back on.

The diagnostic procedure for this error code is lengthy. The code itself is generated by a prolonged high voltage recorded from the air fuel ratio sensor (B1S1) which is the sensor in the exhaust stream before the catalytic converter (89467B on this diagram), either on its own or in conjunction with the heated oxygen sensor (B1S2), which I believe is the sensor after the catalytic converter.

I can see that the garage has installed a new sensor in B1S1, and testing it with a multimeter gives decent readings. It also seems to respond as expected when the ratio is recorded using an OBD2 adaptor - hovering around the magic 14.7:1 (~3.3V) and jumping up in response to a fuel cut.

I've also tested the resistance of the wiring harness that links B1S1 to the ECS, and tested the vacuum pipes for leaks using the carb cleaner trick to no avail.

What would be your next step? I don't want to spend a fortune on replacing parts to track down the issue! Is it worth replacing B1S2 too? Or do you have any other suggestions for likely culprits?

Thanks for your help!

Ari

[flash22]

Has the correct type of sensor been used eg. an actual A/F sensor, what are the resistance readings from the sensor ?

Criteria for the code

P2195

Output voltage of heated oxygen sensor remains at 0.5 V or less during idling with warm engine (2 trip detection logic)

Open or short in heated oxygen sensor (sensor 1) circuit Heated oxygen sensor (sensor 1) No. 1 integration relay (EFI MAIN relay) Intake system Fuel pressure Fuel injector assembly ECM

[aricooperdavis]

Hi Flash,

Thanks for your reply! Where did you get that criteria for the code? The one I've seen in the 1NR-FE manual gives two DTC conditions:

• Conditions (a) and (b) continue for 10 seconds or more (2 trip detection logic):
  (a) Air fuel ratio sensor voltage more than 3.8V
  (b) Heated oxygen sensor voltage 0.15V or more
• While fuel-cut operation performed (during vehicle deceleration), air fuel ratio sensor current is 3.6mA or more for 3 seconds (2 trip detection logic)

The resistance readings look okay:

1 (HA1A) - 2 (+B) : 3.4ohm
1 (HA1A) - 4 (A1A-) : >100kohm

Annoyingly the garage didn't give me a part number for the part that they used - they just listed "lambda probe" on the invoice. I've just had a poke around and it looks like a cheap part; it's got VO3520 stamped in the case and a paper label that's semi-burned that has a date on it and says LAMBDA SENSOR VE3814... there might be more but it's illegible if so. I can't get much out of google for those numbers though - any ideas?

If they've fit a standard lambda sensor rather than a AF/wideband then I'll go back and argue my case.

Thanks for your help,
Ari