CTS - Coolant Temperature Sensor (F7 Type Engine)
So everyone's going on about the CTS. This article shows what it looks like and how to change it.
You will need:
New CTS (e.g. GSF Car parts, £9.50+VAT)
Spanner 21mm
Thin blade or similar to unhook the plug retaining clip (you'll see)
Stage 1 - Gain access
I removed the airbox and moved the throttle cable out of the way. This makes things a lot easier!
This is looking at the side of the engine. Guess what, the arrow points to the CTS.
Note: later engines may differ; after about 1992 the sensors are mounted on the thermostat housing. It's the same sensor - the one with the WHITE socket
Stage 2 - Replacement
New sensor
Loosen the old sensor, then you should be able to unscrew it by hand. One you pull it out some coolant will shoot out the side of the head. Obviously if the engine's been running that will be nearly boiling water so use protection kids.
Screw the new sensor in, not forgetting to carry across the copper washer from the old sensor.
Stage 3 - Finishing Off
Plug in the sensor and replace any parts you might have moved out the way. Top up the coolant and consider that a job well done.
CTS Testing
The sensor can be tested. This involved measuring its resistance at different temperatures. For this you'll need a pot of water on the stove, and an Ohmmeter (or multimeter).
Code:
Temperature Resistance
20 degrees 3061-4045 Ohms
40 1315-1600
80 301-367
90 212-273
Linear Mode
