I have a 2008 C30 T5 and just got this code. Car runs good otherwise. My Autel scanner says code 223B??? Not familiar with this type of code but the description says Rear heated oxygen sensor (H02S) Bank 1 signal missing. Sounds like a circuit code but I can't find any reference to it on line. I'm thinking a wire is damaged or maybe a broken wire or maybe the sensor went bad. I haven't had a chance to get it on a lift to check it out so I thought someone might have some experience with this.
Thanks
Jim

 

yep sounds like the sensor is an open circuit. There are four wires - two are for the heater element and two are for the sensor and it sounds like the sensor is reading open. The rear o2 sensor is used to measure cat efficiency so it shouldn't impact day to day driving. not sure where the connectors for the O2 sensors are for your model - possibly up by the firewall...

 

MT thanks for the reply. I'm hoping it's an easy fix.

 

Well it was an easy fix. Seems something on the road came into contact with the harness for the sensor and cut one of the wires. New NTK O2 sensor at Volvo $304.00 garage price. Retail is a lot more. My cost for an aftermarket NTK was $104.00 and tax. Retail was $255.00. The money they make on these things is nuts! I could have repaired the old one but 76000 miles and 10 years old I just replaced it.

 

thanks for the update.