When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Stock Problems/IssuesDiscussions related to warranty related issues and repairs, or other problems with the OEM parts and software for MINI Clubman (R55), Cooper and Cooper S(R56), and Cabrio (R57).
Hi All,
I've been trying to figure out a persistent issue on my 2009 Clubman non-S. It bogs down when driving over 2,000 RPM, and the trouble codes have pointed towards MAF sensors and O2 sensors. I've replaced both O2 sensors and the MAF, but when I took it for a test drive with the ODBII reader attached and sending data to my phone, the O2 sensor shows no reading. I drove it for about ten minutes, so I assume it was heated up enough.
Before I start throwing more parts at this, can anyone suggest a solid procedure for testing the O2 sensor?
Thanks,
Nick
Does anyone have a diagram that shows the function of the wires leading to O2 Sensor 1? I want to try a couple diagnostics but am having trouble determining which is which. Wires to the sensor itself are Red, Black, White, Yellow, and Grey. Wires on the other side of the connector (to the ECU) are Black, Orange, two White, and two Yellow.
I found a diagram that shows all the pinouts to the ECU and confirmed that the wiring from the connector to the ECU is good. At the O2 connector, I traced the wires to B15, B16, B17, B27, B28, and B30 on the ECU. Can anyone tell me the functions of each of those?
Your troubleshooting would be more focused and accurate if you used a code reader that reads BMW codes.
For example:
-Three different BMW fault codes can trigger generic code P0136
271C DME: Fuel-supply system
273A Oxygen sensor behind catalytic converter, electric
2A7F DME: DMTL leak diagnosis pump, activation
-Two different BMW fault codes can trigger generic code P115C
2775 DME: Combustion misfires, cylinder 3
1. If problem is present with mixture, VANOS, lambda control/oxygen sensor, camshaft control, injection valves, then repair these faults first.
2. Spark plug visual inspection (cracked ceramic insulator, black electrodes, electrode gap, etc.), replace as indicated,
3. Wiring harness electrical check, check contacts (corrosion, insulation damage)
4. Check ignition coil for corrosion, cracks, interchange coils between cylinders as indicated, conduct road test with full acceleration and note whether fault in fault memory migrates, replace ignition coil as indicated.
2B5C DME: Air-mass sensor, plausibility
1. Plug in HFM
2. Check connections/plugs (corrosion, water, etc.) between HFM and DME (CMI-240, CMI-209 and CME-114)
Just an FYI: The O2 sensor fault signified by generic code P0136 is for the 4-wire post-catalyst oxygen sensor (O2 sensor 2) not the 5-wire or 6-wire pre-catalyst oxygen sensor (O2 sensor 1).
Last edited by Maybe, maybe not; Aug 2, 2025 at 07:29 AM.
