KOER Code 538 '93 4.0l
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KOER Code 538 '93 4.0l
I pulled the codes using the KOEO and KOER tests and came up with only the 538 code during the KOER test. The KOEO test showed nothing abnormal. Does anyone have an idea what could throw this code, it seems there are three explanations for this one;
Insufficient RPM change during Dynamic Response Test (Engine Run Self-Test)
Or
Invalid cylinder balance test – throttle position movement
Or
Invalid cylinder balance test – cylinder identification problems
The truck started running rough and using lots of fuel after I changed out the clutch slave cylinder.
Pat
Insufficient RPM change during Dynamic Response Test (Engine Run Self-Test)
Or
Invalid cylinder balance test – throttle position movement
Or
Invalid cylinder balance test – cylinder identification problems
The truck started running rough and using lots of fuel after I changed out the clutch slave cylinder.
Pat
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From: Connecticut
That code just means that the EEC self-tests were not run to perfection (the "goose test" part, to be precise). It's a procedural code, not a substantive one. By that I mean that, the 538 code does not indicate that anything is wrong with the EEC system.
Sounds obvious I know, but you have to re-trace your steps regarding the clutch job to make sure that no hoses or electrical connectors got kinked or damaged or left off, things of that nature.
Sounds obvious I know, but you have to re-trace your steps regarding the clutch job to make sure that no hoses or electrical connectors got kinked or damaged or left off, things of that nature.
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I re-ran the KOER test and made sure I hit WOT this time, and it came up clear. I then ran another KOEO test and got codes 172,173,176 & 177, telling me both banks are running lean and rich. Since my O2 sensors had about 100K miles on them I replaced them, erased the codes, drove around then ran another KOEO test. I got the same four codes as above.
I've checked electrical connections, replaced the plenum gasket and looked for other obvious vacuum leaks but I guess I could be missing more, but still haven't figured out what's causing the problem.
Any ideas on what could be causing all four of these codes to come up? I'm running out of ideas.
Thanks.
Pat
I've checked electrical connections, replaced the plenum gasket and looked for other obvious vacuum leaks but I guess I could be missing more, but still haven't figured out what's causing the problem.
Any ideas on what could be causing all four of these codes to come up? I'm running out of ideas.
Thanks.
Pat
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Joined: Jan 2003
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From: Connecticut
Hmm, that's a doozy. Both rich and lean codes on both banks.
First thing that comes to mind is a dirty or bad MAF sensor. Has it been cleaned lately? Here's some info with regard to that:
http://www.diesel-central.com/Tech/f...s/98-23-10.doc
Another possibility that comes to mind is a bad fuel pressure regulator. Might want to do a FP check.
What year is your truck, and what engine does it have?
First thing that comes to mind is a dirty or bad MAF sensor. Has it been cleaned lately? Here's some info with regard to that:
http://www.diesel-central.com/Tech/f...s/98-23-10.doc
Another possibility that comes to mind is a bad fuel pressure regulator. Might want to do a FP check.
What year is your truck, and what engine does it have?
Post Fiend
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From: Connecticut
Opps, I see now from the title of the thread you have a '93 4.0L.
You ought to consider putting that info in your signature.
You ought to consider putting that info in your signature.
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I cleaned the MAF, there wasn't much on it and it didn't make any difference once I put everything back together. Could a vacuum leak cause both lean and rich indications? I did have a lean indication a while back and replaced the plenum gasket to take care of that one, but I'm not sure what to check next.
I can try the FP check, although I just put a new fuel pump, suction strainer and fuel filter in, and I had the FI's cleaned and flow checked, and they came back good. It was running great until I did the clutch slave cylinder work.
Any ideas are welcome.
I can try the FP check, although I just put a new fuel pump, suction strainer and fuel filter in, and I had the FI's cleaned and flow checked, and they came back good. It was running great until I did the clutch slave cylinder work.
Any ideas are welcome.
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Check the injector circuits to verify that control circuit (TAN wire) of cylinders 1, 2, and 3 show continuity to pin 58 of the ECM and that the control circuit (WHITE wire) of cylinders 4, 5, and 6 show continuity to pin 59 of the ECM. Check both wires for shorts to ground using a logic probe. Check to verify that the oxygen (O2) sensor harnesses are plugged into the proper side sensors. Also check for fouled spark plugs.
As previously stated , make sure no wires got caught inbetween the bellhousing and the cylinder block while installing the trans after the clutch. If you still haven't nailed the problem , check your grounds,
As previously stated , make sure no wires got caught inbetween the bellhousing and the cylinder block while installing the trans after the clutch. If you still haven't nailed the problem , check your grounds,
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