Check Engine Light (CEL) or Malfunction Indicator Light (MIL) on Nissan Frontier

The CEL has been turning on in the nissan for a while.  Suspected it was the fuel filter. Changed it but the light still illuminate after 700m of driving. Spending the whole week checking the car.

This is the sensor that I've check:-
i) Gearbox sensor - there are 4 sensors in the gearbox. Cleaned all the connection and test the car. CEL still illuminate.

ii) Changed the Tachometer sensor (On the bellhousing) and test the car.
CEL still illuminate

iii) Changed fuel filter.
CEL still illuminate

iv) Cleaned the turbo intercooler, cleaned the ambient temperature sensor, refit coolant temperature sensor.
CEL still  illuminate

Running off ideas...I decided to take the multiester/multimeter to test the brake switch. I read somewhere in some forum that the CEL will illuminate if the brake lamp is broken or the switch is broken. Then.....I found the culprit....

 

One of the contact rubber pad is broken. This makes the ECU think that your brake has a problem

 

 

This is how the contact rubber should looks like

Diagram of the brake pedal. Sw1 is signal to the ECU. Sw2 is the brake light.

Replaced the contact rubber pad and test the car....Yahoo!!! CEL is now off ^^v