Check Engine Light but no Codes???

[hclark]

My 03 F350 7.3 "Service Engine Soon" light came on but my code reader shows no codes. I even tried clearing the codes just in case and the engine light stays lit from the moment I start the truck. The truck runs fine with no noticable problems. Any ideas??

[ABoyAndHisToys]

Whats done to the truck and year? Clear the PCM anyway and see what happens

[hclark]

Hi Doc, it is a stock 2003 F350 7.3 dually with 40,000 miles. I did clear the codes in the PCM using the code reader device (did not disconnect battery) with no effect on the SES light. Is it possible that my generic code reader is not reading a Ford unique code? Even if that were the case I would think the light would go out for some period of time after clearing the codes but it stays lit when the vehicle is started.

[hclark]

Update: Broke down and took truck to Ford dealer. Their code reader found codes P1280 and P1211 (0 pressure and 0 volts) which points to the ICP sensor. New sensor cleared the codes and made the SES light go out. Tech was surprised the truck ran at all with a bad sensor. Not sure why my generic code reader would not read the codes. A bad ICP sensor evidently trips the SES light immediately which is why the light would stay on even after clearing the codes.

[lloyd4515]

I was searching these codes and came across your thread. I have these same codes plus a Trans Range code. SES light ON, clearing won't reset the light. Truck starts runs just fine cold and hot (sluggish) just like it always has since new. I don't have access to a real data reading scan tool. I'll check voltage at the ICP sensor to see whether it is sending any signal at all. Thanks for the info.
2003 F350 7.3, 21,000 miles. Lloyd

[elibenson]

These engines can run without the sensor, but it will be a little weird.

Also, for lloyd4515, you probably need a new transmission range sensor.

[lloyd4515]

I checked the ICP voltage today. 5v to the sensor, ground seems to be ok, but signal wire is .031v whether engine is running or not. Doesn't change when wiggling the connector. Sounds like a dead sensor to me. (International dealer?)
I'd like to get a schematic of the Range sensor circuit so I can check it out. Any suggestions on where to get it?

Lloyd
2003 F350 dually, 7.3 Stroke, stock, 21,000 miles

[lloyd4515]

Followup: I bought a sensor on E-Bay, still in the Ford parts bag. CEC went out immediately and truck seems to run better. Have not had a chance to drive it yet. Thanks for the help.
C ya around...