After replacing the PSOM everything appeared to be in great running order on my 1995 F250 4 x 4 with a 460. Tonight when I was traveling the check engine light came on as soon as I reached 75 MPH. Once I shut off the engine the light went out. Everything seems to be running fine but the light came on. Do you have any idea what might have caused this? Any help anyone could provide would be great.

 

checked your codes with a code reader since it started showing the light? if you have a haynes or chiltons manual, it breaks down the codes responses...do that then we will be able to help you alot better

 

Haynes blows in my experience for all cars bes tto use the chiltons manual.

 

Click on the CLUB FTE MEMBER under my user name.
<----- Over here. I have a link on my website there that will show you how to pull codes with a paper clip if you don't have a code reader. This on works in a pinch. However since I don't like counting how many time the MIL lamp flashes I bought a rather inexpensive code reader at the local Kragen's. It was 30 bucks i believe.

 

Okay, I checked the codes and here is what I got:
311 - Thermactor air system/fault during engine run self test
332 - Insufficient EGR flow detected
538 - Invalid cylinder balance test due to throttle movement during test
536 - Brake on/off (boo) circuit not activated during KOER
632 - Overdrive transmission cancel switch/no action during self engine run test

As I stated earlier the check engine light only comes on when I reach 70 mph. Once I turn off the engine the light goes off but comes back on when I reach 70 mph.

Any help would be greatly appreciated. This site is the best.

 

When you do a KOER test after you get the code 10 you do several things. 1 - quickly push the gas pedal to the floor and release. This is call the Dynamic Responce Test (DRT), basically tests the TPS. 2 - The Brake On/Off (BOO)switch must be activated is so equipped. (I believe all vehicle 92 and up have them) Depress the brake pedal and release. 3 - On trucks with electronicaly controlled equipped with overdrive switch (either on the dashboard to the left of the sterring wheel or on the end of the column shifter) must be turned on and off.

On the cylinder balance test, this test turns off fuel injectors ( one at a time) so see if all cylinders are contributing equally as it runs. Basically tests for dead cylinders. The test can be run after the KOER test is finished. The cylinder Balance Test is activated by pressing the gas pedal down 1/4 of its full travel and releasing. When the test starts do not touch the gas pedal until the test is complete.

Code 332 - Insufficient EGR flow detected. Your valve may be dirty and need cleaning. The valve may be stuck. The valve may also be broken and need replacement. Or you may have a slight vaccum leak in the EGR line that prevents the valve from opening fully.

Code 311 - No idea on this one, not familiar with the thermactor air system.

 

My truck is having the same problem did you ever figure oit what was causing the problem?

 

The most recent poster in this thread hasn’t been here since 2009.

If you want help, make a new thread detailing everything about your truck and what is happening with it.

It’s possible you are having the *exact same issue* as the original thread poster, but it’s not likely.