Punto (Mk2/2b) cooling fan not working and car overheats

Currently reading:
Punto (Mk2/2b) cooling fan not working and car overheats

ghobsh

New member
Joined
Jul 31, 2015
Messages
4
Points
1
Hi Guys, I have problem with my punto classic 2006 . the car overheats and the cooling fan doesn't work . I checked the fan motor and is working direct from the fuse box and by activating test from Multiecuscan and working fine. also checked the fan relay and is working . when testing the cooling temp sensor when car is hot the multimeter reads 196 ohm and when car is cold reads O.L and when unplugging the cooling temp sensor socket when the motor is running the fan didn't work.

Note: the temp gauge reading is normal and matches the reading got from Multiecuscan

I really appreciate your help because this problem drove me crazy :bang::bang::bang::bang:
 
There are often two temp sensors, one on the manifold, the other on the cylinder head. Check both.
I'd expect the sensor to close the circuit rather than open it, so when you unplug the sensor, bridge the terminals in the plug. This tells the ECU massive overheat, so the fans should run. If that works, need a new sensor. Sensor is most likely problem.
 
On mine I found the connector pins at the temp sensor were not making a decent connection. clean them and should be OK.
 
On mine the earth trigger wire from the fan relay to the ecu was broken in the harness where it passes behind the battery box. Pale grey wire.
If it's working from MES test than that might eliminate this problem.
 
Last edited:
There are often two temp sensors, one on the manifold, the other on the cylinder head. Check both.
I'd expect the sensor to close the circuit rather than open it, so when you unplug the sensor, bridge the terminals in the plug. This tells the ECU massive overheat, so the fans should run. If that works, need a new sensor. Sensor is most likely problem.


But from knowledge, I think when the sensor is defective i.e gives high ohm value (simulating it by unplugging its socket) the ECU turns to limp home mode and makes the cooling fan to operate continuous .
 
But from knowledge, I think when the sensor is defective i.e gives high ohm value (simulating it by unplugging its socket) the ECU turns to limp home mode and makes the cooling fan to operate continuous .

It does on our car and increases the idles speed slightly. The idle speed increase was how I knew that the ecu could still see the sensor.
 
It does on our car and increases the idles speed slightly. The idle speed increase was how I knew that the ecu could still see the sensor.

RPM increases slightly but the fan doesn't work, where do you think the problem?
 
So
By using mes we can eliminate the fact op has stated the fan works on mes

So the fuse - wiring power and earth - relay - fan itself are okay - ecu to relay feed is okay

This leaves very little wrong here....
Except the ecu / ecu wiring to sensor / sensor....

Yet the cars still overheating....
It makes me wonder....

Only 1 temp sensor on mk2 1.2 8v...
Since its an 8v, chances of aircon is very very slim, so its just a single speed fan....

Ziggy
 
my car is 1.2 L 16v A/T Transmission(cvt) (someone told me it is barva motor!!!!!!) . I want to know is there double contact thermal switch on radiator because I looked around the radiator and found nothing .

Another question, where is the cam sensor?
 
Last edited:
There are often two temp sensors, one on the manifold, the other on the cylinder head. Check both.
I'd expect the sensor to close the circuit rather than open it, so when you unplug the sensor, bridge the terminals in the plug. This tells the ECU massive overheat, so the fans should run. If that works, need a new sensor. Sensor is most likely problem.

you are mistaking mk2 punto for mk1 which have one sensor on rad, other on head as opposed to mk2 which only got one on inlet
 
my car is 1.2 L 16v A/T Transmission(cvt) (someone told me it is barva motor!!!!!!) . I want to know is there double contact thermal switch on radiator because I looked around the radiator and found nothing .

Another question, where is the cam sensor?

Its fitted as standars in a brava / bravo due to size of the vehicle

The punto has this in the sportings and i think others like elx 16v

The cam sensor should be on rhe cylinder head on, near the cambelt / cam pulleys

Ziggy
 
you havent said if car has aircon because if it has you will probably find the resister pack in the fan plastic has failed or the wiring has corroded
just a thought
 
Back
Top