Outer Limits 4x4 Board

Thought I'd do a "How To" for this before I get stuck into the oxy sensor fault finding.

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)

Hopefully the above procedure makes sense?

To reset the codes stored in the EFI computer it is necessary to remove power to it. This can be done by disconnecting the negative (earth) lead on the battery for a couple of minutes and then reconnecting it. OR you can find the relevant fuses and remove power that way. Check after the reset and you should get the "normal" code 1.

You may find the engine will drive a bit differently for a while as the EFI computer appears to learn certain operating parameters and these will need to be relearnt.

david... great work mate! thats tops! now a question for you. i know my oxy sensor is all out of wack cuz i have similiar problems that you did. i've just been ignoring them.... 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)?

Looking good David, but all my problems continue to be mechanical and diagnosed by the spreading stain under the car!

Ill keep it bookmarked though, Thanks.

PV- I'd possibly leave it until you get the extractors done. You'll most likely find it near on impossible to remove anyway- they tend to sieze. I had trouble getting my old one out and damaged the thread doing so! I should have time later today to write some more on the oxy sensor- that will give you some ideas on how to check it out further.

Good luck with the seal Croz- at least it wasn't the rear main on the engine I suppose!

A cracked exhaust manifold can cause O2 sensors to false read if the crack is before the sensor. As the exhaust pulse rushes down the pipe, there is a vacum created behind it (the principal of how extractors work). If there is a crack in the manifold, this vacum will suck in outside air, and the O2 sensor will read this as lean mixture coming from the engine(more air in the exhaust gass). The computer will then try and richen up the mixture to compensate, causeing a rich mixture and poor economy. Have seen commadores (VR with the LH exhaust manifold that always crack near the NO.5 runner) with this problem. Might be worth lookin at, though the majority of time it is the O2 sensor that fails. When replacing make sure that you do not use a sealant, or if you must use one that is O2 sensor safe, the silicone in some sealants roots O2 sensors.
Layto....

hey croz... food for thought..... that stain you say you have.... does it grow bigger each time you drive and park it?? i think i may know whats going on since i had the same issue on my old engine before it went bang..... turned out it was my pcv valve and filter being all clogged up.. caused internal pressure to build up and forced oil to steep out. seemed to get worse if i drove it in long intervials.... just a thought for you to check out. hope it helps. i had thought it was my rear main as well, took it in to a mech to have them do a oil leak test... said they couldnt find any leaks so the first thing they did was tear apart the pcv valve and filter, cleaned it all out, volia.. no more leaks! you just might be lucky.

Hmm, PV... I am pretty sure its my leaky rear diff... it's kinda obvious



dont know where anyone got the idea of rear main from...