Diagnosing a hard fault code

[justbinfishin]

1993 Ranger XLT 4.0 5spd.

Coding 998-118-998-118.... KOER.

Will not give me anything in KOEO test, just whirrs and clicks with no codes forthcoming.

I have been told that the 118 (high voltage ECT sensor) and 998 (hard fault) are related. Is this true? And why the heck can't I get any codes out of KOEO?

It's -43F and I can get my car into a friends garage tomorrow (those AAA guys will hate my guts!!), so any direction before I start checking wires would be amazing!

 

[Matt77]

the PCM may be damaged, or some wiring is shorted?

 

[Sasquatch_Ryda]

Fix the 118 code.

All that 998 means is that a hard fault that will not clear is present.

Fix the first issue, clear and rescan.

 

[justbinfishin]

Fix the 118 code.

All that 998 means is that a hard fault that will no clear is present.

Fix the first issue, clear and rescan.

I'm not quite sure what you mean by "that will no clear is present." When I unplug the ECT sensor, I still get 118-998 and can't get the KOEO but it'll run smooth in gimp mode. When I plug it in it runs like crud and loses power/dies. My thought is that the wire must be frayed and touching a hot wire somewhere, so even though it's unplugged the input to the computer is still above range. Is that a valid thought? I'm going to replace the ECT sensor, because I have one that tested good on a spare lower intake. Any suggestions for the next step?

Thank you for the input guys!

 

[Matt77]

First, comb through all the electronics and cables. THEN start replacing stuff.
A car is like a computer- look first, then change parts.

 

[Sasquatch_Ryda]

Fixed my post, sorry.

You've got a problem with the ECT sensor or the wiring. You need to fix that issue before the 998 code will clear.

 

[justbinfishin]

Fixed it! Resistance was good on sensor, voltage from ECM was good. Had continuity in the return wire as well. Return wire connection was corroded at the ECM. Cleaned it up and I'm running good again!!