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2008 Cadillac SRX P0056 Fault: How to Fix Heater Circuit Issue in Bank 2 Sensor 2

Model: 2008 Cadillac SRX Fault Code: P0056 Posted: 2018-06-14 06:23

I'm looking for help with a recurring check engine light on my 2008 Cadillac SRX, showing fault code P0056. We've already replaced the fuse and checked the oxygen sensor wires—everything appears fine, but the check engine light returns and the code persists. I suspect there might be an issue with sensor placement or wiring. The vehicle is equipped with a 3.6L engine, where cylinder layout follows: passenger side has cylinders 1, 3, 5; driver's side has cylinders 2, 4, 6. Bank 1 corresponds to cylinder 1 (passenger side), and Bank 2 is on the driver's side. Code P0056 specifically refers to the 'Bank 2 Sensor 2 Heater Circuit' fault—this typically indicates a problem with the oxygen sensor located after the catalytic converter on the driver’s side. I believe we may have mistakenly installed the new sensor on the passenger side, before the catalytic converter, which could explain why the code remains unresolved.

Related fault codes
P0056
Comments (12)
Anonymous 2018-06-14 06:59

Try disconnecting the battery for at least 30 minutes to reset the Powertrain Control Module (PCM). This allows the PCM to relearn the resistance characteristics of the new oxygen sensor, which may resolve the P0056 code.

Anonymous 2018-06-14 07:44

Thanks! I'll try disconnecting the battery and see if that clears the code.

Anonymous 2018-06-19 06:08

The battery reset didn't work—the check engine light returned, and the P0056 code is still present.

Anonymous 2018-06-19 10:00

On which side was the oxygen sensor replaced—driver's side or passenger? And was it installed before or after the catalytic converter?

Anonymous 2018-06-19 11:22

Passenger side, before the catalytic converter.

Anonymous 2018-06-19 14:09

Based on my research, the P0056 code in a 2008 Cadillac SRX with a 3.6L engine refers to Bank 2 Sensor 2 Heater Circuit—this sensor is located on the driver's side, after the catalytic converter. It appears you may have installed the sensor on the wrong bank or position. Double-checking this placement is critical for accurate diagnosis and repair.

Anonymous 2018-06-19 14:23

Our mechanic mentioned that cylinder 1 is actually located on the driver's side, which might explain some confusion about sensor positioning.

Anonymous 2018-06-19 15:11

I'd appreciate it if you could share your findings—I’ve been searching for 2008 Cadillac SRX specs but keep getting results for 2003 models instead.

Anonymous 2018-06-19 17:05

It sounds like the sensor was installed on the wrong side—definitely should be on the driver's side, before the catalytic converter, to match the correct bank and position.

Anonymous 2018-06-19 18:20

For P0056 in a 2008 Cadillac SRX, Sensor 2 Bank 2 is located after the catalytic converter on the driver's side. I hope this correction helps resolve your issue—make sure you install it correctly.

Anonymous 2018-06-19 20:03

Thank you so much! We’ll replace the sensor in the correct location and try again. Your insight is very helpful!

Anonymous 2018-06-19 23:09

You're welcome—happy to help with this common issue on the SRX model.