a web site that has a GOOD explanation of the diagnostic
codes and troubleshooting procedures? I am using an AutoXray that shows things like "mixture too rich" etc, and has done the job I expected, but on some of the more vauge codes like "411" which reads "cannot control RPM KOER low rpm control" i need more info. Sorry bout the long post, but I'm trying to nail down some the minor problems with a 1993 F150 SuperCab 302/E4OD/3.55 that my dad bought.

 

http://dalidesign.com/hbook/eectest.html

This is by far the best definition for code testing.

It takes a little while to figure out how to get the codes. ignor the first few light-ups that the check engine lamp does when it's testing it.

The 1987-1991 check engine light is HUGE, I think the 92-96's is very hard to see.

 

What I am looking for is a better definition of what is going on during the test that failed, what is the most probable failing component, and a way to test to see if the component is in fact failed. Also ABS brake code 15 memory failure. Does this mean the ABS "controller" needs to be replaced?

 

I don't think you'll find anything THAT specific. The codes are already as specific as they can logically be, given the way the system works. Sometimes, a different wording helps, so look at my list and a few others. It's rare for the main computer of any Ford system to go bad, so read the code definition for what it says and look at the diagnostics in the Haynes manual. It tells how to check each component and does close to what you're asking for.

 

'preciate that........

93 F150 Supercab 302/E4OD

I'm using an AutoXray Ford XP240 scanner. The codes I am getting (KOER) are as follows:

412 Unable to control RPM (low)
116Coolant temp, Sensor out of range
173 Right HEGO indicates rich
411 Unable to control RPM (high)
632 TCS stuck during KOER

Also you may want to check out this site as they have some refurbished scanners in stock for a very good price.

http://www.autocheckup.com

 

dbrown:
While I certainly am no expert, here is what the codes mean to me:

412 Unable to control RPM (low)

The throttle control motor is not responding when told to decrease the rpm. You have to take it from there. This means the motor could be stuck or defective, the wire to it could be disconnected, or the wiring could be defective, etc. The next step would be to put a voltmeter at the connector and watch to see if there is the specified voltage (check the manual), and if it varies.
Also, there could be an air leak around the control valve that causes it to be unable to reduce the bypass air enough.

116Coolant temp, Sensor out of range

This normally means that the engine was not up to specified temperature when the test was performed. This is very common in cool weather.

173 Right HEGO indicates rich

The computer is getting a RICH (hi voltage) signal from the o2 sensor. This could be a defective sensor (most common), or a vacuum leak, or several other causes. If the sensor if fairly new, disconnect it from the harness and carefully measure the output voltage while the engine is running to see if it changes. Make sure you DO NOT do a continuity (ohms) check. That will ruin the sensor.


411 Unable to control RPM (high) Similar to 412. Same tests. Either there is no signal to the motor, or it is not responding.

632 TCS stuck during KOER This sounds like you didn't do the wide open throttle test at the right time. Not sure about TCS.

Hope this helps.