94 Explorer KOEO and CM codes.

[wvmedic]

I get an intermittent check engine light, so I checked the codes and got.

KOEO: 11

CM: 124 (TP voltage was higher than expected)

CM: 332 (EGR did not open/respond during test or if memory code, did not open intermittently)

Ok now for my question as I am not great with electrical, with CM 124 what dose this mean?

And for CM 332 is the EGR bad or could it be the EGR Vacuum Solenoid or the EGR Valve Pressure Sensor?

Also would either of these cause poor gas mileage?

Thanks Jeff.

 

[MrShorty]

Should be a third digit with that KOEO code. Just want to make sure we have all the information.

Along the same lines, probably the next thing I'd do would be to run the KOER test.

When it passes KOEO and KOER, and I'm left only with CM codes, that indicates that the faults are intermittent, which makes them harder to track down. I would probably start by clearing CM, test drive, and see if I got the same codes back or not.

 

[wvmedic]

Thanks MrShorty,

You are correct the KOEO code is 111.

I am using a test light to check the codes, and I guess my grey hair is sucking oxygen from my brain because I don’t totally understand how to run the KOER test. I had my wife sit in the truck and hit the brake and the motor revved up slightly and powered down she then did a brief WOT, then I was lost.

Thanks Jeff.

 

[MrShorty]

From my notes on pulling EEC-IV codes thread:

test 2: Key On Engine Running (KOER) test.

1) Preheat engine. Setup same as for KOEO test.
2) Start engine.
3) Engine id is output. This is a code to indicate the number of cylinders the computer is set up for, and is half the number of cylinders. So you should get three flashes/pulses for a 6 cylinder engine (2 for a 4 cylinder, 4 for 8 cylinders).
4) Immediately after engine ID is output, press brake so computer can test BOO switch. (FYI, other applications have a power steering pressure switch that is tested at the same time by turning the steering wheel. Not necessary on Explorers).
5) Engine will go through a low speed and then a high speed test. These tests will take up to a couple of minutes. During this time, if you want, you can test timing advance with a timing light. Computer will advance timing a fixed 20+Base BTDC. Base is almost always 10 BTDC, so you should see about 30 BTDC timing.
6) At end of KOER test, as engine spins down, you will get a pulse/flash for the dynamic response test (DRT test, aka "goose" test). Perform a brief wide open throttle.
7) KOER codes are output.
8) Turn engine off and disconnect to end test.

Which are you having trouble with?

 

[wvmedic]

Ok I disconnected the ground from the battery for a few minutes, then drove to the store and check engine light stayed on.

Got back and checked the codes again.

KOEO pass 111

CM code 332

KOER code 332

So with this code is it the EGR, DPEF sensor or EGR Vacuum Solenoid

And will this affect my MPG?

Thanks Jeff.

 

[MrShorty]

Any problem in the engine management system has the potential to effect your gas mileage.

So with this code is it the EGR, DPEF sensor or EGR Vacuum Solenoid

Well that is the question, isn't it. A code by itself can't tell us which component has failed. I haven't done much with the EGR system, because my '92 doesn't have an EGR system. From what I understand, this code indicates that the DPFE signal to the PCM didn't respond correctly. Could possibly be an electrical fault in the DPFE sensor circuit (though this often triggers KOEO codes), a plugged/missing vacuum line in the EGR system, an unresponsive EVR solenoid, or a bad valve.
I would probably start with a basic inspection. Make sure all the electrical connectors are connected and appear intact. Check all vacuum hoses to make sure they are there, connected, and not plugged. I would probably check Vref to the DPFE to make sure it's 5V, and check the signal out of the DPFE to see if it responds at all. Check for vacuum getting to the EGR valve. Check the pipe from the exhaust manifold to the valve.

 

[wvmedic]

MsShorty, I was typing you a reply lastnight and my PC crashed. Thanks for you're reply and I will trace down the problem.

Thanks Jeff.

 

[dizzybirdtrane]

did you ever find out anything more with this, wv? I've got the same code
(332) issue after just putting brand new vaccuum tubes (there's only 2) on the DFPE/EGR Vaccuum Pressure Sensor (what Autozone calls it).