I drove my 99.5 7.3 F-350 1 mile to a friends and hooked it to the OBDII to get a code for my abs light.it had not been drove all day. we hooked into the pcm and he noticed the temp at 375* it was idleing. is this right he didnt think it should have been that high???Will the engine coolant temp sensor, if it were bad,show a high temp of 375*? On the OBDII it showed a temp of 375* thanks for any help.

 

The coolant temp sensor on our trucks (auto tranny) reports a "state" not an actuall temp you have to look at oil temp to see a real temp. What were you using to scan the truck, while they are ODBII connectors the Powerstroke does not have to be fully ODBII compliant so it could be the scanner couldnt interpret the signal correctly.

The manual tranny trucks do have a temp sensor (Thermosistor) and the PCM changes fueling characteristics at 225* to prevent overheat.

 

its a 6spd. he works for the citys service center reparing their fleet. he uses it on the powerstroke ambulances/firetrucks.i assume its a general OBDII for most vehicles.we were scanning for engine codes. it had a screen that showed the temp and RPM's the rpm were correct with the idle. could it have been the engine oil temp sensor that read 375 it showed no trouble codes. the trucks been running fine. and on cold mornings a little hard to start without being plugged in. the oil temp sensor makes it idle high so that means its working i guess

 

Well we know it is a wrong reading, unless you missed that giser shooting out of your truck, the sensor should cause a P0117 or P0118 code to show up

 

Does this mean that there are 2 temp senders on the manuals? or

Is there only one temp sender on the manuals, just like the autos, that does sometyhing different?

 

just one sensor on the handshakers it just acts like a real sender instead of the idiot light driver we have in the auto's.

 

I replaced the water pump, and broke the water temp sender tip off, replaced the sensor, and pig tail, gauge works fine, A E shows 302* for the coolant temp input, auto trans, is there a sensor for auto trans trucks that will read properly on the gauge, and in A E ? Is this affecting anything with the ecu?
TIA

 

Is your gauge reading correctly? If so, you're good. The coolant temp isn't exposed to the PCM on auto trucks, so AE will never read coolant temp correctly on them.

Mark

 

Thanks for the reply, Yes, inst panel gauge reads correctly, well, like it always did, normal for an auto i am learning, the needle is in the middle of the normal range brackets, when cold A E shows a low * number I forgot, as it warms up the temp starts rising till it hits 302*, but engine is only at 190* or so, wow and I thought I had a temp gauge, I guess the oil pressure gauge is the same, I have a 4 pod a pillar gauge set, I guess I should have gotten an 8 pod one, do they even make one?

 

Mark is spot on, the coolant gauge on an AT is a simple gauge. It does not pass thru the PCM so no scanner can see a signal there, but they do get confused trying. The PCM gets it's "how hot is this engine" info from the oil temp on an AT truck. However on MT trucks ECT does run thru the PCM. On the wiring diagram attached below note how the ECT gauge (top left) is marked MT only. So if you hook up AE to an MT truck you'll get a good reading of ECT, but connect AE to an AT truck you get wackiness.

My best guess as to why they are different is that the engineers wanted to exclude the additional heat "noise" given to the coolant from the oil-to-water cooler of the AT.

For more ideas on mega gauge setups, grab a cold one, a comfy chair, and google "gauges Tugly".

 

Android device, Torque Pro, OBDII Bluetooth or WiFi adapter, and tablet mount. That's my 27 (or so) gauge pod. It costs less, and it's easier to install than 4 more gauges.

 

I experienced the same scare when AE showed me 300+ degrees a while back. Boy I thought there was something terribly wrong with my pick-up.

Mark and the others are right on about the Coolant temp reading through AE. I called AE about it five or so years ago. They told me it only applies to the Manual Trans vehicles.

 

Thanks for all the great replies. reps sent

 

WOW, cool set up, maybe in the future, I would drive myself crazy keeping up with all of of that info, and would probably have a wreck monitoring it, I have a hard enough time with what I have now. I am in the injector Hell you went through now, next week another set will go in from another company, had 2 go bad from 1st install, replaced them, now another one went bad, 3rd time under the valve covers, going with Bostech this time, any thoughts?

 

That is one nice looking steering wheel. I gotta do mine one of these days.