Hi the aux fan in front on my radiator is on as soon as the key is turn on, also my ecu talk LCD will not connect to the ecu. I have Ben doing general work on tha car today. Nothing that should affect either of these though. Any ideas would be good. By the way the fan relay is fine.
No, the fault thrown by the coolant sensor is due to a circuit fault, not that the sensor has no water on it. Is the car running OK? If you can't connect via a laptop that can sometimes mean there is issue with the ECU itself which will make the fuel pump run at max speed (and the aux fan run at max speed) and the car will not idle smoothly.
hmm car was not running smoothly anyway it has to go for a tune after mods. would the fuel pump continually run without the car running and acc on only. its a bit strange as car was sitting with accessories on. messing with stereo settings, then the fan started up. i have a stock ecu that i could change out and try.
It will not stop, as the ecu see's a circuit fail. As the ecu has no idea how hot the engine is it will trigger the fan and raise idle speed etc. Make sure the contacts on the coolant temp sensor and plug are clean and tight. This could stop the aux fan coming on by default and lower idle the speed.
I had the same problem. The fan just came on while I was driving. I pulled the CTS sensor connector out and in again and it stopped. i suggest you check the the CTS connector terminals. If the connectors on the loom are green then try to clean them with Bicarb of soda in a water solution with a tooth brush. From my tests if you pull out the CTS connector while the engine is running the fan comes on and stays on. When i reconnected the sensor it stopped. MichaelZ
ok the plugs on the sensor were all good the sensor is brand new and checked it with another. however when i play with the plug on the ecu it goes on and off etc. the plug it self is brand new as i have a new wiring loom. the centre bolt is tight. it seems to be the end of the plug closest to the engine when the ecuis installed. Is there any aditional way to make the plug tighter on the ends. its a big plug.
Check pin 28 on the ECU. Yellow /Green trace Using the online service manual ihave found that this is the wire from the CTS Coolant Temperature Sensor (Also known as the Engine temp sensor) to the ECU. Check that the ECU connector is on square and no pins have been pushed out of the connector or damaged. Is the new sensor OEM or after market replacement? MichaelZ
is oem sensor when pushing the plug harder onto the the ecuthe fan stops and the ecutalk lcd communicates properly again until the plug is knocked.
You don't rely on the bolt to pull the ECU loom connector home to the ECU. If you have a look at the plug, it may not be parallel with the ECU and using the bolt to pull it in alone does not guarantee this. You will see one end maybe pushed in further than the other and if it is, back the bolt off a few turns and push the side that is sitting out then as you tighten the bolt, make sure each side is being pushed home equally.
Agree with checking ECU connector. As 90TTZ says the bolt does not line up the connector. It stops the connector from coming off. You must ensure the connector is parallel and is fully inserted before tightening the bolt. MichaelZ
thanks guys i didnt think it would make sense to have a blot in the middle be better with one each end.
Cable tie around the ECU and back to the plug if that helps. You might need to put a drop of dielectric paste on the pins of the plug before putting it back in its socket.
