Coolant sensor fault woes
#1
09-28-2018, 06:51 AM
Join Date: Sep 2018
Location: Seattle
Posts: 4
Likes: 0
Received 0 Likes
on
0 Posts
Coolant sensor fault woes
Hi Folks. I'm new to Mini, but not vehicles. Got this '08 R56 S from my wife's cousin for a song (free puppy?!). So, after replacing the clutch/flywheel/rear main due to a cracked actuation arm (is that common?!), and then the thermostat b/c of a P0118 code afterwards, I now have a P0117 Temp sensor low output code.
I replaced the sensor, to no avail. The code will clear but then come right back, indicated by either/both the fan coming on high and the CEL.
Full disclosure, when I first replaced the thermostat, I had the intake breather heater connector swapped with the sensor plug (easy mistake!) Straightened that out, but the fault persists.
Car starts right up and runs great until it gets up to temp, then stumbles and becomes un-driveable, at which point it starts throwing O2 sensor codes, MAF codes, and misfires.
Coolant is full and bleeds fluid. Heater gets hot. Sensor checks out with resistance dropping with heat. I do only get 3.3V at the sensor plug (should be 5V?).
In the "secret menu" accessed in the dash, at number 7.00 the CTEMP has no value and shows up as +++C. ??
I've disconnected the battery overnight in an attempt to reset the ECM. Is there a different way to reset the ECM?
If there's nothing left, I'll have to tow it to a shop with better ECM diagnostics.
Thanks for any help!
I replaced the sensor, to no avail. The code will clear but then come right back, indicated by either/both the fan coming on high and the CEL.
Full disclosure, when I first replaced the thermostat, I had the intake breather heater connector swapped with the sensor plug (easy mistake!) Straightened that out, but the fault persists.
Car starts right up and runs great until it gets up to temp, then stumbles and becomes un-driveable, at which point it starts throwing O2 sensor codes, MAF codes, and misfires.
Coolant is full and bleeds fluid. Heater gets hot. Sensor checks out with resistance dropping with heat. I do only get 3.3V at the sensor plug (should be 5V?).
In the "secret menu" accessed in the dash, at number 7.00 the CTEMP has no value and shows up as +++C. ??
I've disconnected the battery overnight in an attempt to reset the ECM. Is there a different way to reset the ECM?
If there's nothing left, I'll have to tow it to a shop with better ECM diagnostics.
Thanks for any help!
#2
09-28-2018, 07:17 AM
I've got the same issue just couple months ago. My CEL says coolant temperature circuit short, I don't recall which code number, it must have been either 0117 or 0119, I may be wrong.
For the longest time I've been trying to tackle this problem, even planned to just open up the wiring looms and create my own wires straight from sensor to ECM. But before I got that far, I looked at the connector wire prongs and realized it looked a bit different than the other similar plugs nearby. The metal contacts aren't extended all the way out, so I'm guessing even after it's plugged to the sensor snuggly, it probably just didn't stay in contact to get readings to the ECM. My suspicion is further supported when I plug in the OBD to log temperature readings, it stayed at one value (288 degrees), and it never changed. So I went to PelicanParts.coom and got a new plug and basically refitted the prongs into the new plug. Metal contact's visible and after plugging in, all is well. I no longer get this annoying fan running on high for 5 minutes after I shut off the car. No more limp mode, too.
Of course, shortly after, the HPFP went out, so there's that next project. Just gotta love these cars but hate the parts.
For the longest time I've been trying to tackle this problem, even planned to just open up the wiring looms and create my own wires straight from sensor to ECM. But before I got that far, I looked at the connector wire prongs and realized it looked a bit different than the other similar plugs nearby. The metal contacts aren't extended all the way out, so I'm guessing even after it's plugged to the sensor snuggly, it probably just didn't stay in contact to get readings to the ECM. My suspicion is further supported when I plug in the OBD to log temperature readings, it stayed at one value (288 degrees), and it never changed. So I went to PelicanParts.coom and got a new plug and basically refitted the prongs into the new plug. Metal contact's visible and after plugging in, all is well. I no longer get this annoying fan running on high for 5 minutes after I shut off the car. No more limp mode, too.
Of course, shortly after, the HPFP went out, so there's that next project. Just gotta love these cars but hate the parts.
#3
09-28-2018, 10:21 AM
Gonna admit my stupidity here. I have been chasing a po128 code for the last month. I had change the thermostat 5 time trying to delete this code. Rebuilt wire ends changed parts i didnt need to.
Finally broke down and sent it to a mini specialist. Dumb *** me had the radiator hoses on back ward which was flowing in the wrong direction.
Just a word of caution!
Finally broke down and sent it to a mini specialist. Dumb *** me had the radiator hoses on back ward which was flowing in the wrong direction.
Just a word of caution!
#4
09-28-2018, 12:26 PM
Gonna admit my stupidity here. I have been chasing a po128 code for the last month. I had change the thermostat 5 time trying to delete this code. Rebuilt wire ends changed parts i didnt need to.
Finally broke down and sent it to a mini specialist. Dumb *** me had the radiator hoses on back ward which was flowing in the wrong direction.
Just a word of caution!
Finally broke down and sent it to a mini specialist. Dumb *** me had the radiator hoses on back ward which was flowing in the wrong direction.
Just a word of caution!
Didn't think that's even possible since all hoses have some sort of preformed shape to them, it's kinda trivial to install it. But glad you've finally got it resolved. I did do something like that back in the Nissan days with throttle body coolant hoses. LOL.
#5
09-28-2018, 08:46 PM
Join Date: Sep 2018
Location: Seattle
Posts: 4
Likes: 0
Received 0 Likes
on
0 Posts
Success is usually found within the minutia
As mentioned earlier (thanks for the tip!), connector pins in place but either not making, or in my case making intermittent contact is the worst fault to diagnose! I was beginning to rationalize the expense of a new ECM...!
So, the puny two-pin connector to the coolant temp sensor, which I replaced when the original bottom cover disintegrated in my hands, but was able to preserve the original crimped pins, snapped back into place with such a confidence inspiring “click” I didn’t look twice at it.
After a week of unsuccessful diagnosing, test driving, sputtering, high speed fan running and 40 amp fan fuse pulling... it took disassembling a brand new connector to isolate the pins to check how they fit the pins of the sensor! Adjusting the contacts with a jeweler’s screwdriver, reassembling, and... No fault codes!!
Wow. Easily one of the most confounding problems I’ve had to fix.
Now, pardon me while I go drive this thing!!
So, the puny two-pin connector to the coolant temp sensor, which I replaced when the original bottom cover disintegrated in my hands, but was able to preserve the original crimped pins, snapped back into place with such a confidence inspiring “click” I didn’t look twice at it.
After a week of unsuccessful diagnosing, test driving, sputtering, high speed fan running and 40 amp fan fuse pulling... it took disassembling a brand new connector to isolate the pins to check how they fit the pins of the sensor! Adjusting the contacts with a jeweler’s screwdriver, reassembling, and... No fault codes!!
Wow. Easily one of the most confounding problems I’ve had to fix.
Now, pardon me while I go drive this thing!!
#6
09-29-2018, 10:32 PM
As mentioned earlier (thanks for the tip!), connector pins in place but either not making, or in my case making intermittent contact is the worst fault to diagnose! I was beginning to rationalize the expense of a new ECM...!
So, the puny two-pin connector to the coolant temp sensor, which I replaced when the original bottom cover disintegrated in my hands, but was able to preserve the original crimped pins, snapped back into place with such a confidence inspiring “click” I didn’t look twice at it.
After a week of unsuccessful diagnosing, test driving, sputtering, high speed fan running and 40 amp fan fuse pulling... it took disassembling a brand new connector to isolate the pins to check how they fit the pins of the sensor! Adjusting the contacts with a jeweler’s screwdriver, reassembling, and... No fault codes!!
Wow. Easily one of the most confounding problems I’ve had to fix.
Now, pardon me while I go drive this thing!!
So, the puny two-pin connector to the coolant temp sensor, which I replaced when the original bottom cover disintegrated in my hands, but was able to preserve the original crimped pins, snapped back into place with such a confidence inspiring “click” I didn’t look twice at it.
After a week of unsuccessful diagnosing, test driving, sputtering, high speed fan running and 40 amp fan fuse pulling... it took disassembling a brand new connector to isolate the pins to check how they fit the pins of the sensor! Adjusting the contacts with a jeweler’s screwdriver, reassembling, and... No fault codes!!
Wow. Easily one of the most confounding problems I’ve had to fix.
Now, pardon me while I go drive this thing!!
Thread
Thread Starter
Forum
Replies
Last Post
Ixx
R56 :: Hatch Talk (2007+)
3
04-24-2016 12:23 PM
BRebels
R50/R53 :: Hatch Talk (2002-2006)
11
04-21-2015 05:56 AM
Drivetrain Fault Code P0327 Knock Sensor Circuit Low
Inked469
Drivetrain (Cooper S)
8
05-20-2014 10:02 AM