Hey guys, hope y'all are hanging tight with Covid and all. It's been awhile since I last posted, but I've run into an oddity here. Long-ish post warning! First, some recent history (my car is a 2009 JCW):

1. Mid-June: Walnut blasted
2. Same time: Changed water pump to address coolant leak. Replacement method: lowering/raising engine after removing engine mount without removing the friction pulley. Just removed WP pulley, then WP.
3. Test drove no issues, no codes
4. When parked in garage, a bigger coolant trickle, so changed coolant pipe (it had cracked). Removal method: removed airbox, lowered intake manifold (i.e. didn't remove from engine bay), removed thermostat housing. Burped the coolant system.
5. Took it out for a proper test drive - when I fired it up, code P0118 / P0118PD appeared, so I thought hey, sensor dead, easy peasy, right? Nope. This is where I'm stuck...
6. Engine starts perfect, not rough, heater blows hot after warming up, which are not symptoms of a bad CTS, IIRC. I'd clear code each time and code returns on start-up.
7. Swapped out previous CTS with new one just for kicks - no dice - same issue, so back in the older one goes.
8. Also found blown 7.5A blade fuse in engine compartment (fuse diagram shows something engine-related, but not sure exactly what). Replaced with new, and blew again. Bad ground? Short? But where? The only ground I know is the big one by the top-left engine mount, which I removed for the WP job. It was properly re-installed.

I don't know how to proceed. The radiator fan runs great, just goes into fail-safe mode everything P0118 pops up, so it runs regardless of whether the engine is cold or hot, but shuts down after about 5-10 minutes when engine is off. Any advice would be appreciated:
- Anybody experienced a problem like this before? Would appreciate your assist.
- What is the proper way to test the CTS with a multimeter - can you backprobe (I don't think so in this case)?
- What about the wiring harness? Does it start from the CTS and routes directly to the ECU or does it traces further/somewhere else behind the engine?

Thanks in advance!
- Aaron

 

I would think the OBD code is only telling you part of the story. Are there any Mini specific codes in the DME memory? What tool are you using to read out the codes?

 

I thought so too​, which is why I ordered a proper Bummer/Mini reader than my generic one... hopefully it gets here by the end of the week. Is there anything I can inspect in the meantime? Mechanicals I can handle, but electrical ain't my forte.

 

Op, did you ever get an answer to your recurring OBD code? Did you get a Mini scanner to get you more info? Curious minds want to know...