Service engine light

[Russell]

So when I'm going up a good size hill in my 2003, E350, 4x4 diesel, 7.3 van and I give it enough throttle to kick it in to low the service engine light comes on for about 2-3 minutes. I assumed it was due to not enough air, maybe I need an inner cooler, but while at the West coast expo in AZ, I was told by "professionals" that my 2003 has an inner cooler. Is that right, is it a factory item. So what is causing the idiot light to come on? Air filter is new, exhaust is 5".
It doesn't happen if I just hit the downshift button, only if it downshifts itself.
Anyone else experience this?

[simplesez]

Check engine lights are often emissions related. With that 5-inch (is that even possible?) did you disable any of the O2 sensors? Do you have a catalytic converter still?

BTW the 7.3 PSD in the E350 doesn't have an intercooler AFAIK. That shouldn't matter unless you did some kind of swap between a truck and van engine and now you have a sensor missing.

Sorry I can't help with specifics but you should get a OBD reader so you can check that code. Even if it is intermittent it is stored by the computer. The auto parts stores have one you can borrow. Come back with the code it reads out an we can help you.

[REF]

Unless you or the previous owner installed an inter cooler, mind you at great difficulty and expense, our E350 7.3’s do not have one, a big difference between vans and pickups. Did these “experts” put eyes on it, or were they just “assuming” since they were probably familiar with the 7.3’s in trucks?
As for your issue with the dash light and downshifting going uphill, it could be a number of things, but namely a possibility of transmission issues since it happens when left to downshifting on its own. Notice any slipping? Another point to make, do you have an EGT (exhaust gas temp) gauge? How about a way to monitor trans temp, like a scanguage?
BTW, don’t use cruise control going up hills, it’ll often spike your EGT’s trying to maintain speed, in fact I hit the overdrive off button when on an incline approach to maintain rpm’s and speed. Which brings me to my next point, early on in my ownership, I noticed my dash light came on with cruise control, it ultimately cleared, but I think the issue presented when the RPM’s and speed were not being met and fuel was being dumped, raising EGT’s enough to trip a warning.

[1der]

Confirmed - 7.3 diesel in a van does NOT have an intercooler nor does it have a catalytic converter.

Do you have a chip or tuner installed?
Have you checked your air filters?

5" exhaust is huge - where does the 5" pipe start? It is almost certainly not from the turbo itself as there is no room.

If you can get the OBD scan as recommended you might have visibility into the issue. It is possible you do not have enough back pressure w the 5", or the 5" has created a data parameter on one of the sensors that puts that sensor out of range.

[Russell]

Your right it's a 4 inch exhaust, not 5.
I do have a chip an it runs at 60 percent unless I'm towing. I found no codes on the computer, not even on my Edge display. I guess I will have to check the code while the light is on or soon after.
The exhaust temp is low during the downshift and proceeds to lower as the rpms go up.

[1der]

Which chip? Try stock tune and see if problem replicates.

I had a DP tuner for a bit that would throw a SES light for a bit under load, then the light would turn off after the ECU determined the parameters were back within spec. These chips mod a number of sensor readings to cause the fuel/throttle to think it is under a different load condition. This can cause the relationships between the data parameters to think the ECU has a SES light trigger event present.

[Nrobert10]

If running a tuner it might be an overboost issue that causes the light. Pretty common with some tunes, it clears itself after a few min when boost is normal.

As 1der said try to reproduce with tuner in stock mode.

Most of the aftermarket diesel shops sell a overboost blowoff to keep the sensor from see too high of boost.