Hello. I have a 09 Mini Cooper S Convertible and just did a thermostat housing replacement last weekend.

I replaced it with OEM thermostat housing with new sensors included.
After the thermostat housing replacement, I got a few code that popped up:

P0117, P0117P (GONE NOW)
P0118, P0118P with CEL light.

When I try to see the engine temperature through hidden option 7, it's not reading the temperature and showing CTMP-MOM ttt o C.

I refilled with coolant and bled it several times.

I usually have the engine temperature visible almost all the time to see if it's overheating, but now I can't see and making me nervous.

Yesterday, all of a sudden, the car had red colored engine overheating light on my dash. I pulled it over to the side, the a/c air was blowing warm. Turned off the engine, scanned, only p0118 code. After 1 min of shutting it off, it was back to normal.

I'm guessing it's my coolant temperature sensor that is bad? the brown colored clip with a U green clamp? Any advice would be great.

Thank u in advance.

-seb

 

According to OBD codes:

Causes

A code P0118 may mean that one or more of the following has happened:

A bad connection at the sensor
An open in the ground circuit between the ECT sensor and the PCM
A short in the voltage feed between the sensor and the PCM A bad PCM (less likely)
A bad temperature sensor (shorted internally)

Possible Solutions

First, if you have access to a scan tool, check the reading of the coolant sensor. Does it read a logical number? If so, the problem is likely intermittent. Perform a "wiggle" test by wiggling the connector and harness to the sensor while watching the reading on the scan tool. Watch for any drop-outs. Drop-outs would indicate a bad connection. If the scan tool reads an illogical temperature, check the resistance of the temperature sensor. If it is out of specs, replace it. If it is in specifications, unplug the sensor and, using a fused jumper wire, jumper the two terminals of the connector together. The temperature reading should now be maxed out to above 250 degrees F. If not, there is likely a problem with the ground circuit or voltage supply. Check for 5 volts reference voltage at the connector. Also check for ground presence at the connector. If you do not have 5V ref. and/or ground continuity, check for these back at the PCM connector. If you have these at the PCM connector, then repair open or short between the PCM and the sensor. If you do not, remove the offending wire from the PCM and then check for proper voltage at the PCM pin. If it's present now, repair short on the circuit. If it isn't present after removing the wire and checking the pin, replace PCM

NOTE: Usually, P0118 is indicative of a bad temperature sensor, but doesn't rule out these other possibilities.

See if any of this helps you diagnose the issue.

 

Also, make sure all the connectors are on the correct sensors. For some reason Mini has 3 leads coming off the same point on the harness that are all the same connector type. The temp sensor gets the white and yellow connector. The brown and black goes to the air hose next to the turbo inlet. The yellow goes next to the temp sensor

 

Thanks

 

Hey everyone,
Just replaced a ton of stuff (timing chain, cam gears, water pump, thermostat, dual-mass to single mass flywheel conversion, clutch, plugs, coils, valve cover gasket) on my 2009 Mini Clubman S with 74,000 miles. Most of the parts were ordered from ECS (great team over there by the way).

My issue is that I'm getting an ECT reading of 286F which I saw someone else had on here as well, but everything suggested did not work for me.

This all started because my clutch was slipping and since I had to have the car down, I figured I would do a ton of maintenance to it since the wife agreed.

Thermostat replaced, tested cooling system by pressurizing for 5 minutes (no pressure loss). Held vacuum on the system for 5 minutes with no vacuum loss at all. Used the vacuum to fill the coolant.

Getting a P0118 code, and with the car in accessory (not cranked over) the cooling fans immediately come on and the ECT reads 286F. I reset the code using my Innova scanner, fans turn off for about 10 seconds, code immediately comes back and fans kick back on. This is all without starting the car.
Ran out today and picked up another Coolant Temperature Sensor and am having the exact same problem.

One thing I did notice is that I do not have the green connector to the sensor like everyone says they have, but also my wire colors don't match (orange/black). Also there aren't any other plugs that would fit other than the single wire plug that goes into the side of the engine next to the temp sensor. The plug that goes into the PCV has (yellow/white) but the plug end is completely different and doesn't fit into the temperature sensor correctly (I tried).

I am at an absolute loss here, I called ECS and Vince reached out to his tech who told me to bleed bleed bleed. I purchased a vacuum system that day and it worked marvelously.

What in the world am I missing here?
Connector plugged into the sensor, fans kick on immediately when car is in accessory but not cranked. Connector not plugged into the sensor and the situation is the same.
It's pointing to wiring, but where would I even start? The fact that the ECT is reading 286F with the engine bone cold is what makes no sense to me. The cooling fan 40A fuse is good.

I don't think I've posted here before, and I'm sorry that I had to reanimate this corpse of a post, but I've been through every other post and followed all the advice and have come up empty...
Thanks everyone,

WeaponizedaD

 

What BMW fault codes are stored in the DME?

The service manual shows that the coolant temperature sensor and map thermostat share a 4 wire connector (coolant temp sensor, yellow and black wires; map thermostat, orange & white wires).

Does the coolant temperature still read 286F with the coolant temperature sensor unplugged? When unplugged, is a different fault code found?

 

Short answer, yes.
I have one temp sensor currently in the thermostat housing, accessory on, car off, 286F with the radiator fan spinning hard.
When I unplug the sensor connector, accessory on, car off 286F with the radiator fan spinning hard.
When I plug the sensor connector into the coolant temp sensor I bought today, same issue as above.

When I clear the code the check engine light clears, and the fan turns off, but then after about 10 seconds the CEL re-triggers and the fans kick back on, all while showing 286F and never changing.

I have checked and triple checked all of the connectors in that vicinity as multiple people have mentioned that the connectors are similar (none of mine are which is odd).
It has to be a wiring issue, right?
Also, thank you for sharing that page, I need a repair manual for this thing immediately!

 

What are the wire colors in your coolant temp sensor connector? Do either of the two wires have voltage reading?

Do you have a scan tool that reads BMW fault codes?

 

Innova 5610, seems to be reading my Mini codes without issue. I've used it for other CELs.
Okay, remember how I said that the two connectors did not match and I did not see a connector with a green end anywhere?

Get this...
The brown CAP was on the correct wire for the PCV, but would not fit into the PCV connector because the green cap (that I did not see anywhere), was jammed in there. Once I popped the brown cap off, the connectors looked exactly the same.

So, I have yellow/white on one connector, and black/orange? on the second connector. They both match male-plug wise, but I need to restore the colored caps on the correct connectors.

Here's what I think happened: I disconnected both at one point and the caps stuck inside the sensors themselves, so I just got lucky when I plugged them back in (I think this is when I was installing my intake).

This time, one cap stuck, one didn't, and the whole plan was shaken.

Un-freaking-believable. I didn't screw up the timing chain, but these connectors have become my Achille's heel :-D

 

P0118 is a generic P code, not a BMW code. For your Mini, you get much more information from the BMW code.

Problem fixed?

I assume that the connector for the coolant temperature sensor has the yellow & white wires.

The connector for the engine breather heater has orange & brown wires.

 

Okay here's the update:
Switched the connectors, started the car, cleared the stored codes. CEL remained off, but now I'm getting the P0117 instead of the P0118 and my ECT is showing -40F (which I guess is better than the inside of an oven).

My guess is that having those connectors flip-flopped burned up the coolant temperature sensor?
I still need to burp this thing, but getting rid of that original CEL was a humongous relief! Thank you for your help with that!

 

Now unplug the coolant temp sensor and then check the temp reading and fault code. Any changes?

 

I'll report back tomorrow after I get this thing to show me coolant coming from the bleeder screw (which it doesn't right now). I've emptied this thing 3 times now trying to track down anything I might have done wrong and it all came down to those two connectors being swapped. If there are other issues I'll work on those tomorrow. Thank you very much for your help!

 

Alright, I unplugged the coolant temp sensor, put the car into accessory, was unable to clear the P0117 code, the fans kicked on immediately, ECT still showing -40F (open to ground?).
So, seeing that it was -40F whether plugged in or not means that the sensor is dead?

 

I believe the DME normally supplies 5 volts to the coolant temperature sensor to calculate the engine temperature.

In contrast, the engine breather heater relay supplies 12 volts to the engine breather heater.

By swapping the two connectors, the engine breather heater relay supplied 12 volts to the engine temperature sensor. This high voltage could potentially damage the engine temperature sensor, its two wires, and/or the DME. This is what you should consider moving forward. I hope its either a damaged wire or sensor. Good luck!

 

Sir, thank you so much for your help with this!
I'm hoping it's the sensor and not the DME. I have a new sensor ready to go, so finger's crossed!

Quick update:
Connection circuit open (unplugged) is showing -40F
Connection circuit jumpered (plugged) with a paperclip shows +286F
Plugged in the new Coolant Temp Sensor that I had bought a few days ago, temperature showing 63F which is the ambient temp in my garage.

Wiring and DME seem to be okay, and the temp sensor that's in the thermostat now is cooked. Just need to replace it with the good one! What a learning ride this was!