Hey everyone! I'm brand new here. Live in Alaska. Bought a 99 7.3l a few weeks go. 250k miles. Buyers inspection from reputable shop found cyl #5 & 8 high low open. Cleared codes and passed run ability test. Could not replicate. So I bought the truck. Paid $6k for it which was a steal. SES light comes on intermittently for a few seconds and goes back off. Mainly when I'm just leaving the house. Once it's fully warm the SES light mainly stays off. Snap On reader today says bad ICP. Checked icp and no oil in connector. Has a slight miss on idle. What do u guys think?

 

Nobody has any suggestions?

 

AkSam good talking to you tonight, maybe we will get a chance to read your codes with my AE Saturday. Hold on tight, these guys around here will have some suggestions for you soon, they are very helpful and know their way around these 7.3's like the back of their hands.

 

i wonder if it has the EBPV on your engine? i dont know if 99 had them or not. since its a start up type issue, maybe it does and the wires disconnect to the solinoid on the pedestal.

im just throwing darts into the black abyss though. just a thought.

 

My e99 has EBPV. I am not knowledgeable enough to help with the SES light.

 

I did recently clean the ebpv tube and it's closed when high idle kicks in. Can hear it on exhaust. The snap on code reader came up with p1280 I believe. Something with icp. I can un if icp and doesn't make any difference as far as running.

 

There is a 42 pin connector above the drivers side valve cover. There is a bolt that hold it together. Pull that connector and make sure all connections are clean. Also look under that harness where it passes over the valve cover for chaffed wires. If you search "42 pin connector, there are numerous threads on ohming out that connector while you have it apart to check the condition of injector harness connections.

 

I have had this same problem when the engine is cold and the EBV is closed. It has throws a SES light but is not on long enough to store it. There have been a few codes that have stored one was a TPS code and the other an ICP lower than desired. I don't think I would be too concerned about it as long as you don't get a code after it's at operating temp and the EBV is open fully IMO.

 

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That actually makes sense. So you're thinking it may just be sticking? How would that trip an icp code though?

 

I'm still trying to figure this one out. I think it has to do with the ICP commanding more pressure but can't get it because of the conflict with the EBPSensor. I don't know much about the mapping of all the sensors and how they all work together so that's my best guess.

 

ICP has nothing at all to do with the exhaust pressure regulator operation. That operates off of the lubrication oil side of the circuit.

P1280 - ICP circuit low input
Possible causes:
-Biased ICP sensor/PCM
-Open ICP sensor circuit
-Short to SIG RTN or PWR GND on ICP sensor circuit
-Open in VREF circuit

 

I've i selected all my wiring and it all looks good. No chaffing No oil in icp harness. Can it still go bad without leaking oil? If I unplug it when it's running it has no change in idling. Does that mean the pcm is already reading false icp pressure? Only thing different when I un plug it is the SES light is constantly on

 

You'll need to read the voltage from the sensor with the scanner, as well as what the PCM is reporting for pressure. Post the voltage and the pressure and we can see how they compare based on the values in the book.

 

AE all up and running now! 100%

 

We hooked up the AE today and if anyone is interested in interpreting I can send a copy of the file we recorded.