Intake air temp sensor code p0111/weird wiring.

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

Chrismb5.7

Member
Joined
Apr 14, 2019
Posts
56
Reaction score
18
Location
Dandridge, TN.
Ram Year
2004
Engine
Hemi 5.7
My engine light came on a while back (code p0111) so I've been dealing with my IAT sensor and this odd wire... Here's the video explaining.
 

Fast69Mopar

Senior Member
Joined
May 10, 2019
Posts
1,997
Reaction score
1,706
Location
Texas
Ram Year
2004
Engine
5.7 HEMI
What you have installed there is an adjustable intake air temp sensor. The bass knob type setup in the cab is just an adjustable potentiometer that is wired into the intake air temp sensor wiring to control the voltage that the PCM sees. I have used some of these setups in the past. By adjusting the potentiometer and controlling the voltage that the PCM sees, the idea is to make the PCM think that the air charge is cooler when it is entering the engine so it will make the fuel mixture richer and therefore make more power.

The issue I would have with mine is what is possibly happening to you right now. The adjustable setup has probably been turned too far one way and has the voltage either too high or too low and the PCM is setting a corresponding DTC. Also, the adjustable potentiometer may have failed internally and is no longer able to provide the correct voltage to the PCM. Either way something needs to be done. If the voltage goes too high or too low the PCM detects this and sets a DTC.

You can connect a scan tool and monitor the IAT voltage while turning the knob and setting the voltage to a point that is low enough to show the PCM that the air is cooler entering the engine and then mark the adjustable knob so you know where to turn it to if you or a friend turns the knob.

If you want to eliminate this setup from your truck, cut the electrical tape off of the harness and remove whatever is installed into the wiring harness and remove the adjustable setup in the cab.
 
OP
OP
Chrismb5.7

Chrismb5.7

Member
Joined
Apr 14, 2019
Posts
56
Reaction score
18
Location
Dandridge, TN.
Ram Year
2004
Engine
Hemi 5.7
What you have installed there is an adjustable intake air temp sensor. The bass knob type setup in the cab is just an adjustable potentiometer that is wired into the intake air temp sensor wiring to control the voltage that the PCM sees. I have used some of these setups in the past. By adjusting the potentiometer and controlling the voltage that the PCM sees, the idea is to make the PCM think that the air charge is cooler when it is entering the engine so it will make the fuel mixture richer and therefore make more power.

The issue I would have with mine is what is possibly happening to you right now. The adjustable setup has probably been turned too far one way and has the voltage either too high or too low and the PCM is setting a corresponding DTC. Also, the adjustable potentiometer may have failed internally and is no longer able to provide the correct voltage to the PCM. Either way something needs to be done. If the voltage goes too high or too low the PCM detects this and sets a DTC.

You can connect a scan tool and monitor the IAT voltage while turning the knob and setting the voltage to a point that is low enough to show the PCM that the air is cooler entering the engine and then mark the adjustable knob so you know where to turn it to if you or a friend turns the knob.

If you want to eliminate this setup from your truck, cut the electrical tape off of the harness and remove whatever is installed into the wiring harness and remove the adjustable setup in the cab.

Oh okay that makes a lot more sense. So is this something you would recommend keeping? Or would it be best to remove?
 
OP
OP
Chrismb5.7

Chrismb5.7

Member
Joined
Apr 14, 2019
Posts
56
Reaction score
18
Location
Dandridge, TN.
Ram Year
2004
Engine
Hemi 5.7
Also what would be the normal IAT? I just went for a drive and turned the knob, my scanners live data is now showing IAT of 104°f while moving at 45 mph around 1400 rpm. Didn't really see what it was at idle, 130-140ish?? But is this normal?
 

crash68

ACME product engineer
Staff member
Administrator
Supporting Member
Joined
Mar 20, 2016
Posts
10,700
Reaction score
16,707
Ram Year
2015
Engine
3.0 EcoDiesel
Also what would be the normal IAT? I just went for a drive and turned the knob, my scanners live data is now showing IAT of 104°f while moving at 45 mph around 1400 rpm. Didn't really see what it was at idle, 130-140ish?? But is this normal?
Your IAT while moving shouldn't be to far above the ambient temperature unless you have a turbo,supercharger or your running a "CAI" that draws air out of the engine compartment.
To give you an idea, running about 12-15 psi of boost traveling at freeway speeds my CAC outlet temp is about 15°F over ambient.
 
OP
OP
Chrismb5.7

Chrismb5.7

Member
Joined
Apr 14, 2019
Posts
56
Reaction score
18
Location
Dandridge, TN.
Ram Year
2004
Engine
Hemi 5.7
Your IAT while moving shouldn't be to far above the ambient temperature unless you have a turbo,supercharger or your running a "CAI" that draws air out of the engine compartment.
To give you an idea, running about 12-15 psi of boost traveling at freeway speeds my CAC outlet temp is about 15°F over ambient.

No cai, stock with a Spectre performance filter. Temperature here outside is 82°f. So is 104°f too high? Should I remove this setup? I have never dealt with this. I went from a '92 350 to an '04 hemi. The difference is huge lol.
 

crash68

ACME product engineer
Staff member
Administrator
Supporting Member
Joined
Mar 20, 2016
Posts
10,700
Reaction score
16,707
Ram Year
2015
Engine
3.0 EcoDiesel
No cai, stock with a Spectre performance filter. Temperature here outside is 82°f. So is 104°f too high? Should I remove this setup?
Unless your using this adjustable set up for performance reasons or to "band-aid fix" a problem, your probably best to put the stock sensor in.
 
OP
OP
Chrismb5.7

Chrismb5.7

Member
Joined
Apr 14, 2019
Posts
56
Reaction score
18
Location
Dandridge, TN.
Ram Year
2004
Engine
Hemi 5.7
Unless your using this adjustable set up for performance reasons or to "band-aid fix" a problem, your probably best to put the stock sensor in.

Well it is the stock sensor. Not factory stock, but factory spec. I'm just asking if I should get rid of the adjuster knob. And is 104°f too high for it to be running?
 

Fast69Mopar

Senior Member
Joined
May 10, 2019
Posts
1,997
Reaction score
1,706
Location
Texas
Ram Year
2004
Engine
5.7 HEMI
104° is a tad high for an ambient temperature of 82°. Bring that temp down a little while watching your scan tool. I was able to go as low as 67° with the engine at normal operating temps without setting a DTC.

If the adjustable setup worries you then go ahead and remove it from the truck.

If you want to keep it for the performance aspect, make some type of marks on the knob so you know what temps it will be set at.

You'll be fine either way.
 
OP
OP
Chrismb5.7

Chrismb5.7

Member
Joined
Apr 14, 2019
Posts
56
Reaction score
18
Location
Dandridge, TN.
Ram Year
2004
Engine
Hemi 5.7
104° is a tad high for an ambient temperature of 82°. Bring that temp down a little while watching your scan tool. I was able to go as low as 67° with the engine at normal operating temps without setting a DTC.

If the adjustable setup worries you then go ahead and remove it from the truck.

If you want to keep it for the performance aspect, make some type of marks on the knob so you know what temps it will be set at.

You'll be fine either way.

Yesterday when I went for a drive I turned the knob all the way down and that put it at 104°. I can't get it any lower so I think I'm going to remove it. It's been more trouble than it needs to be. But thanks a lot for the info. I've never dealt with this situation and now I know.
 

Fast69Mopar

Senior Member
Joined
May 10, 2019
Posts
1,997
Reaction score
1,706
Location
Texas
Ram Year
2004
Engine
5.7 HEMI
If the temp will not go any lower than 104° then the potentiometer inside the box is the wrong ohm range to properly control the voltage of the sensor. No worries though. Just remove it from the vehicle and be done with it.
 
Top