The Feroza EFI computer has some capabilities to self diagnose faults within the EFI system. It does this by knowing what sort of output range all the EFI sensors will give if they're serviceable. If an output from a sensor goes outside it's normal operating range then a fault code should be logged in the EFI computer's memory and the "CHECK ENGINE" warning light below the tacho may illuminate to warn of a fault condition.
To access these codes there is a diagnostic plug in the engine bay mounted on the firewall. As you face the engine bay it is on the right hand side near the igntion coil (at least this is the position in Aussie Feroza's) NOTE: I have relocated the plug in mine due my my dual battery system- so use the below photo only to get an idea of what the actual plug looks like.
The plug is a green colour and should have a blanking cap fitted to keep out water and dust. This will need to be removed in order to gain access to the electrical pins inside. There is a small release lever on the side of the plug to do this- then pull the cap out.
With the engine stopped and the ignition in the off position you will need to short two of the pins together. To do this I've found a small test lead such as these are very useful: http://www.dse.com.au/cgi-bin/dse.store ... View/Q1900
In the below picture the pins to be shorted out are marked with the orange loop
Here's the shorting lead in place
Once again remember that I've relocated my plug due to the dual batteries.
Double check to make sure you've shorted the correct pins!!
Once you've done that return to the driver's seat with a pen and paper to write down the codes.
The codes are flashed by the "CHECK ENGINE" light on the instruments. It will begin to flash once the ignition is turned to "ON"- do not start the engine. The codes will be repeated, so don't panic if you misread them; they are also permanently stored and can only be erased by removing power to the EFI computer.
How to decipher the flashes:
Look for the flashes, the time interval between flashes is important for working out what the previous flash count indicates.
-The CHECK ENGINE light will stay on for 0.5 sec each time
-If there is a 0.5 sec gap after a flash, then the next flash is added to the previous count total
-If there is a 2.5 sec gap this indicates there is another new fault code about to be flashed
-If there is a 4.5 sec gap then that indicates all the fault codes have been read and the cycle is about to start again.
Some examples of how to read the codes:
Now the codes:
1 Normal - no fault codes stored
2 MAP Sensor
3 Ignition Signal (distributor pickup)
4 Water Temp Sensor
5 Oxygen Sensor
7 Throttle Position Sensor
8 Intake Air Temp Sensor
9 Vehicle Speed Sensor
10 Starter Signal (can be caused from push starting)
11 Switch Signal (aircond switch, idle switch, throttle position sensor)
now my gas mileage has pretty much gone to shit. my question is this, with my stock exhuast on there and being all cracked up, should i replace my sensor or wait until i get the new one fitted (will be a while)?
