By doing a simple routine, we can read the error codes recorded in the ECU. The error codes are interpreted from the pattern of flashing of the Engine Check Light (ECL) in the dash.
The above pic shows the schematic of the 16 Pin OBDII port. For the Mitsubishi lancer 4G15, only pins 1, 4, 5, 7, 9, 16 are available. The OBDII port of my car is located under the dash board on the driver side- straight under the steering. We have to lie down on the car floor to clearly see it though.
1. Turn ignition key to OFF position.
2. Short pin 1 and pin 4. We can use a metallic paper clip- inert one end of the clip to pin 1 and other to pin 4.
3. Turn ignition key to ON position.
The Check engine light in the dash will blink in a pattern. If there are no error codes, the light will stay on for 0.5 seconds, then stay off for 1 second and this pattern will repeat.
If there are error codes, then the error code can be interpreted from the pattern. A 0.5 seconds duration of illumination represents a unit of 10 and a 0.2 seconds illumination represent a unit of 1.
In my car, there was a 0.5 second duration illumination followed by four 0.2 seconds duration illuminations. Which means the error code was 14 !.
A table which shows the error codes and reason. I don't say I have 100% faith about the authenticity of this data.
11 Oxygen sensor
12 Intake air flow sensor
13 Intake air temperature sensor
14 Throttle position sensor
15 ISC motor position sensor
21 Engine coolant temperature sensor
22 Engine speed sensor
23 TDC sensor
24 Vehicle speed sensor
25 Barometric pressure sensor
31 Knock sensor
41 Injector circuit
42 Fuel pump relay
44 Ignition coil
36 Ignition circuit
From this, error code detected for my car was Throttle position sensor error. I need to verify this with an MUTII scanner used by Mitsubishi A.S.S. If both my finding and the tool are having an agreement, then we can conclude that the above table is correct.
PS: To clear the error codes, the -ve terminal of the battery should be disconned for more than 16sec. I havnt done this since I am waiting to go to Mitsu A.S.S and confirm the error code is indeed 14.
Update: Even after repeated visits to the Mitsu A.S.S in TVM, couldnt verify the error code as they dont have the MUT scanner with them at the moment. After reading some more reliable sources online, it seems I can almost conclude that the error is indeed TPS Error.