914-SHO MAF CEL code

[3d914]

Got around to testing the MAF sensor today. Recall that on our initial startup we got some CEL codes - one of which was 26 - MAF (out of range).

Using the MAF Test URL posted by Maurice, I went through all the tests. I also took the MAF apart and cleaned it - it needed it.

All the static tests clearly passed. The running test was somewhat conclusive. I wasn't able to get the motor to idle long enough to get up the temps to normal, but when I did test the MAF (at pin D) with it running, the voltage value stayed relatively steady between 1.4 and 1.37 - walking up & down steadily. Since the swings weren't wild and radical - as indicated in the test guide - I'm assuming its OK. Thoughts?

When I rerun the motor, shut off, and go check codes, I'm still getting #26 - along with the others. Do I need to clear the PCM first before rechecking?

Is there a procedure for that?

 

[luigisho]

Codes will be stored in the pcm over the short term unless you clear them out. Not sure what your setup looks like, but I usually unhook the battery and let all the power drain from the system for about 10 minutes.

 

[3d914]

Codes will be stored in the pcm over the short term unless you clear them out. Not sure what your setup looks like, but I usually unhook the battery and let all the power drain from the system for about 10 minutes.

luigi, the battery positive gets disconnected when ever I'm done testing and sits for days, but I don't think its clearing the codes. There's gotta be a way to do a hard reset.

 

[Shovert]

Quoted from sdpatt on a thread I found in search. Maurice
"One last item is how to clear the continuous codes, so that you can see if new ones crop up. This is simply done by disconnecting and then reconnecting your jumper after all the tests have been run and the codes have been received [with the ignition key in the ON position]."

 

[luigisho]

luigi, the battery positive gets disconnected when ever I'm done testing and sits for days, but I don't think its clearing the codes. There's gotta be a way to do a hard reset.

I usually disconnect both terminals when I want to be sure to clear the pcm. I think clearing the KAM- keep alive memory- procedure is to disconnect the negative cable for a minimum of 5 minutes.

http://www.troublecodes.net/Ford/

 

[3d914]

Quoted from sdpatt on a thread I found in search. Maurice
"One last item is how to clear the continuous codes, so that you can see if new ones crop up. This is simply done by disconnecting and then reconnecting your jumper after all the tests have been run and the codes have been received [with the ignition key in the ON position]."

Maurice, do the codes cycle twice or more than that before stopping?

 

[Shovert]

I remembered on my 89 Mustang [same eec-iv] they repeat. But I use a Ford code reader. But I was unsure on SHO. I found this. Maurice
http://www.shoforum.com/showthread.php?t=101886&highlight=codes+repeat
Post #5 Bubba.

 

[rubydist]

they repeat twice if you are counting them manually.

a 'hard' reset of codes is done by disconnecting the jumper while the codes are being flashed.

 

[3d914]

OK, well I made several attempts to clear the codes using the methods above, but no go. When I go back to check codes, the old ones are still there.

Perhaps I have a PCM that is possessed?

 

[luigisho]

You pull them without running the motor?

 

[3d914]

You pull them without running the motor?

Yes, the motor was run Friday. Since then I've been pulling codes, trying to clear codes, pulling codes, trying to clear codes, - I'm just running in a bloody circle. I've even got the headache to prove it.

 

[luigisho]

i would have one too. Out of ideas except maybe unplug the main harness to the unit. Sounds like they are stored in there power connected or not...

 

[Shovert]

I have done searchs on eec-iv could not find nothing. Only idea I got and probably won't work but won't hurt. Disconnect battery and hook both both battery cable together. [both cable off battery]. I have read some air bag drain codes that way. Just a crazy idea. Maurice

 

[3d914]

Maurice, your idea with the pos/neg leads got me thinking about the grounds. I'm going to review all my notes and EVTMs for ground info to make sure I didn't miss something. I may not have the PCM grounded as thoroughly as required.

Keep ya posted.

 

[Off Road SHO]

Last pin in each row , 20, 40, and 60, need to be grounded.

Tom

 

[Shovert]

Pin #20 goes to body ground, Pin #40+#60 goes the plug connection near battery and ground to the battery cable. In other words those last 2 need to go direct to battery the other is ok to go to metal that is a ground. [I confirmed this with spare 3.2 harness I have]
The reason I mention this. On my 2.3 turbo forum [uses the same eec-iv type computer] many move the battery to trunk. [obvious to transfer weight to rear] Even when they run heavy + and - cable have computer problems. The way they solve is to run wires from those 2 pins direct to main ground at the battery.
I know yours on stand and it maybe this way. Thought I needed to mention to inform you [if needed] and other that maybe making a RWD conversion.
Mine has those two wires to the - body bolt of battery ground. Maurice