Quote:
Originally Posted by flxfxp
Lately I've been getting transmission overheating errors, which seem to not correlate to driving behavior. It happened a few times when I came off the freeway and end in stop and go traffic, but lately it's been doing it on a "warm" start, after I used the car an hour before starting it.
It goes into limp mode and doesn't want to use the second clutch, causing long shift times. It also comes and goes, which to me is an indicator that it's not the actual temperature, but rather a faulty sensor.
Thoughts? Has anyone else ran into this issue? How much was the repair?
Thanks,
Dennis
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My first thoughts are DCT oil change (check that the seals aren't leaking and the DCT oil isn't low. Second thought are temperature sensors. From the drive logic manual I somehow found on the internet...
MDCTTransmission Sensors
The following sensors are mounted in the transmission and their signals are sent directly to the M DCT electronics:- Input shaft 1 speed (Hall) sensor monitors rotation and direction of transmission shaft 1.
- Input shaft 2 speed (Hall) sensor without rotation direction detection for the transmission shaft 2.
- Clutch oil pressure (Piezo) sensors for clutch 1 and 2.
- 3 temperature sensors (NTC), one for the ejected clutch oil and two redundant temperature sensors for the M DCT electronics.
- 4 linear (Hall) sensors monitor the selector rod position.
- 1 double (redundant) parking lock (Hall) sensor.
The oil sump temperature is measured using a complex temperature map and checked against the temperature of the clutch oil by the M DCT electronics.
Other thoughts, such as the oil pump or oil to coolant heat exchanger, are expensive items.