Still tracing an intermittent fast idle so I checked engine codes per the Haynes manual. The KOEO test revealed a code sequence of 3-3--1--3-3. The KOER (is there another key position that keeps the engine running?) test revealed the following:

quick 4 flashes to confirm half cylinder count
34 count pause
1 flash
10 count pause
1 feeble flicker
~5 count pause
then a sequence of 5 2 8 6 3 2 5 3 8 6 3 2

One guess is the engine off test reveals code 33 (insufficient EGR flow or throttle position erratic output) twice with a flash in between. If this is a 2-digit system, the engine running codes are 52, 86, 32, 53, 86 again, 32 again. The Haynes manual doesn't list codes 52 or 86. If this is a 3-digit system, I don't understand the engine off codes, and the engine running codes are 528, 632, 538, 632 again. But the Haynes manual doesn't list code 528.

Can someone make sense of these code sequences?

I removed the battery a few days ago to work on the master cylinder. I assume this erased the codes so they are a reasonably fresh set.

Sixto
'93 E150 Chateau 5.8 185K miles

 

Ford reader book says 528 Clutch switch circuit fault,
T est conditions C continuous memory code
I'll t ag on your thread awhile

 

Code 52 is a power steering pressure switch circut open.....Code 86 is a shift solenoid circut failure.......Check engine light codes for OBD1/OBD2 Vehicles

 

I am a novice at these two digit vs three digit codes. My codes were read from my 1994 5.8liter engine by a repair shop and all codes were 3 digit. I have a ford code reader and the book with it has 3 digit codes.So help me here what am I missing.

 

Your van should be an EEC-IV system and use 3 digit codes. During the KOER test, the mechanic is supposed to do certain things at certain times, like floor it for a second, cycle the OD switch, tap the brake pedal, turn the steering wheel. The codes are from not doing these things.

The codes are here http://www.troublecodes.net/Ford/ The KOEO is simpler. Have you double checked the KOEO codes? Disconnecting the battery will not erase the stored codes but will erase the KAM(keep alive memory) which when erased, the truck will have to relearn for about 10 miles.

<table border="1" width="87%" align="center"><tbody><tr><td>528
</td> <td> (M)
</td> <td> </td></tr></tbody></table>

<table border="1" width="87%" align="center"><tbody><tr><td>632
</td> <td> (R)
</td> <td> </td></tr></tbody></table>


<table border="1" width="87%" align="center"><tbody><tr><td>538
</td> <td> (R)
</td> <td> </td></tr></tbody></table>

Does the check engine light stay on? I've owned a '93 E350 5.8 since 1998 and it has had an intermittent high idle since I've owned it. I can usually get it to idle down by hitting the gas pedal quickly to the floor and quickly releasing it. When that didn't work I'd turn the engine off and restart it and that worked.

 

Well.....if your using the dashboard IP light and counting the flashes it will be two digit codes, if you use a Code reader you should get three digits, I'm glad OBD-2 came out.......LOL

 

I am tagging along since I got same problem....and if I turn the engine off and right back on the idle goes down. Are you implying that you could never get yours fixed so you lived with it?

 

right, I put up with it. I don't think it ever had any codes from that issue and it didn't happen often. This van became a secondary work vehicle 9 years ago so it doesn't get a lot of use now. She has 240K miles and still runs really well.