2006 379 Pete w/cm870 ISX.

[Peashooter67]

Short of the long both my peoplenet and my laptop both show that I have an ambient air temp sensor. The data/temp while driving or not shut w erratic temp values.

How do I find this temp sensor and before anyone says that it’s in my mirror, no it is not. That temp sensor only provides fore my dash gauge and show correct temp.

I know the input from n my ecm is pid #19. Peterbuilt was no help and says my ecm don’t have an ambient air sensor also to not be confused with ambient air pressure sensor.
Local shop says on frame near front on driver side.

Any help here?

2006 379 with Cummins ISX.

[marek4792]

Look in front of your radiator, usually behind the grille or bumper.

[Mrkentee]

(09-18-2023 )Peashooter67 Wrote:  Short of the long both my peoplenet and my laptop both show that I have an ambient air temp sensor. The data/temp while driving or not shut w erratic temp values.

How do I find this temp sensor and before anyone says that it’s in my mirror, no it is not. That temp sensor only provides fore my dash gauge and show correct temp.

I know the input from n my ecm is pid #19. Peterbuilt was no help and says my ecm don’t have an ambient air sensor also to not be confused with ambient air pressure sensor.
Local shop says on frame near front on driver side.

Any help here?

2006 379 with Cummins ISX.

My 2010 386 has two. One in the mirror, and one by the left rear shock along the frame rail. And this is what it looks like.
   

[Peashooter67]

Any one with a pre deff truck?

MrKentee sir

I do genuinely appreciate your answer. I really do need someone with a 2005 or 2006 Pete or Kenworth with an 870 ISX to answer this for sure.

I’m looking at my inside driver side frame rail every chance I get best I can without getting on my back on hot concrete or asphalt.

[Peashooter67]

Any one with a pre deff truck?

MrKentee sir

I do genuinely appreciate your answer. I really do need someone with a 2005 or 2006 Pete or Kenworth with an 870 ISX to answer this for sure.

I’m looking at my inside driver side frame rail every chance I get best I can without getting on my back on hot concrete or asphalt.

[Emeryville64]

I have a 2006 & 2007 379 Peterbilts with 870's. I have looked at both trucks,(the engine is out of the 06) and I can not find this Temp sensor on them. I have looked at both trucks with Paccar E-CAT and cannot find a Ambient Temp sensor other than the one in the mirror. In the Cummins Servive manual I can find the sensor in the wiring diagram going to Pin 19, but that is all the information I can find. when I get a chance I will hook my computer to the 07 and see what i can find that way. sorry this is of really no help, but im curious myself. I've looked all over the 06 and can't find anything on the frame. I took the engine out myself and don't remember seeing or unplugging that sensor.

[Peashooter67]

(09-20-2023 )Emeryville64 Wrote:  I have a 2006 & 2007 379 Peterbilts with 870's. I have looked at both trucks,(the engine is out of the 06) and I can not find this Temp sensor on them. I have looked at both trucks with Paccar E-CAT and cannot find a Ambient Temp sensor other than the one in the mirror. In the Cummins Servive manual I can find the sensor in the wiring diagram going to Pin 19, but that is all the information I can find. when I get a chance I will hook my computer to the 07 and see what i can find that way. sorry this is of really no help, but im curious myself. I've looked all over the 06 and can't find anything on the frame. I took the engine out myself and don't remember seeing or unplugging that sensor.

Thank you for looking , my readout for ambient air temp is now —- where before even erratic I had signal. This is the same for me as well. You can see it in the sensors list on the diognostics laptop and see it in the PID list but can’t find its source.

Perhaps the source is the sensor in the mirror and it feeds the ecm in the wire system someplace.

Since I don’t have sensor signal I can’t unplug it to find out. I’m certain I read somewhere there was one “triangle shaped” in the wire bundle in the frame near the front. It definitely reads temp in the ecm but where is its source.

[Peashooter67]

I found this mystery ambient air temp sensor and found it by accident.
In insite the ambient air temp sensor is actually your egr temp sensor or at least I think it is.

It was reading erratically for a while causing derates and high egt and then one day shortly after my query here it just quit and put out three dashes. This week end I got really tired of running incercles with no resolution from anywhere and just start unplugging every wire plug I could find.

Wow

When I unplugged the egt temp sensor all the sudden the ambient air temp sensor started showing a reading of 72* constant with no change. Plug it back in - - -, unplug it 72* and my full throttle derate went away.

[Rawze]

(10-18-2023 )Peashooter67 Wrote:  I found this mystery ambient air temp sensor and found it by accident.
In insite the ambient air temp sensor is actually your egr temp sensor or at least I think it is.

It was reading erratically for a while causing derates and high egt and then one day shortly after my query here it just quit and put out three dashes. This week end I got really tired of running incercles with no resolution from anywhere and just start unplugging every wire plug I could find.

Wow

When I unplugged the egt temp sensor all the sudden the ambient air temp sensor started showing a reading of 72* constant with no change. Plug it back in - - -, unplug it 72* and my full throttle derate went away.

I am not so sure that the amb sensor itself is actually the egr temp sensor. You likely still have not fount it.. or it may be calculated (some vehicles, it is only calculated) via looking at several other sensors. The ambient temp sensor does compare itself to other sensors at ecm power up, so it could simply be coincidence that the faulty EGR temp sensor was effecting the amb sensor readings indirectly.

Also, that particular temperature of 72 (or sometimes 73) F is used as a default value, assigned to the amb temp sensor, when it bypasses and cannot be evaluated properly.

I.E.> Your description of what happened to the amb sensor is very coincidental to what happens when it falls back to its default value, and not reading any actual temps, for one reason or another.