Need some help guys...

[ugstang17]

@ugstang17 I'm relatively new to tuning anything without jets and power valves. What's the (4th grader) difference between IAT and IAT2? I didn't realize there was more than one? When I was getting my P0113 I'm pretty sure the X4 read "IAT2 high."

When datalogging, will IAT show up on the x4's default program? Or do I need to create one with this livewire program?

I have every intention of calling Finishline today. I seriously doubt I'll get anything done at work, lol. I'm also going to call Brenspeed. They're 4 hours away, so I'm not actually going to tow the car there when Finishline is 2 hours away, but they're kinda the eForce unofficial YouTube spokespeople. Maybe one of these shops has seen something...

On GT500's there is a second IAT sensor on the SC as well as the initial one in the MAF. The ECU has acommodation for the second IAT sensor on the intake runner of the SC. Pre 15 Mustang GT SC packages like Roush and VMP would also use that available input in the same way and then tune to monitor IAT 2. Downside was that IAT would be all you saw if you had a premium model GT with the LCD display. You would have to datalog to see IAT2 temps which is what pulls timing when IAT temps rise above 130-135 on PD applications.

For whatever reason (I have heard lots of speculation but nothing solid so I won't elaborate) on 15+ ECU's this IAT2 input is no longer used except on the Roush phase 1 and 2 packages with their "tune". Any PD SC package I have come across being used on 15+ cars provides a split harness to redirect the so called IAT2 sensor on the SC to the IAT.

Therefore there is nothing on the IAT2 input even if you datalog for IAT2 as I understand it. I only can tell you how the data is collected on 15+ my comprehension on why is vague because the 4111 I was given just didn't seem to jive so I won't regurgitate it since it could be 'bum gouge'.

The only reason I suggest datalogging iat2 if the PID even exists, is in the event Ebrock wants to see it. IF you already have it that is one less thing for them to ask for putting you behind even further on your resolve. I am merely trying to think ahead of them on this aspect. You can bet it may very well boil down to sending them datalog files at this point.

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[Jobodizo]

This is all very interesting, because back when I was getting my P0113 CEL the explanation on the x4 was IAT2 high. I wonder if I’m getting correct IAT values when I pull the battery because it’s resetting to look at IAT, but then it sits overnight in the cold and the computer wakes up and is looking for but doesn’t see an IAT2?

 

[ugstang17]

The only way to know for sure would be to disconnect and very carefully read the voltage value between the two pins. You will not be able to read the voltage to ground because the signal is isolated within the ECU and uses internal ECU ref return according to limited prints I have. The voltage however would have to be sagging pretty low I would think to effect that output. Take your voltage reading at the battery first. Then take your voltage reading (KOEO) at the connector for the IAT sensor. The only other potential problem here would be a high resistance between the IAT and the connection points at the ECU providing IAT and Sig return. There is also within LIVELINK II a PID called IAT volts which may hopefully be a validated PID on the ECU for the Mustang. Not all PID's are valid. I am merely looking at the unvalidated list of PIDS for Ford on Livelink II. Another reason I like datalogging with linvelink. You can monitor voltage as well through this and compare what the ECU is seeing to actual if you woiuld wish to probe the IAT and teh Battery prior to data logging. You can datalog with KOEO (Key on Engine off).

 

[ugstang17]

I just made a cf4 (it's actually a CF4 file not a CFG file sorry for the mis reference) for you to use through Livelink II. It includes battery voltage, IATF, IATF, and IAT volts. Sine I cannot validate these PIDs they will either work when you start to log with LIvelink or it will tell you which PIDs are not compatible. Regardless it will then start logging the valid PIDS. THis will allow you to see the votlage of the battery.PM me an email address if you want it and I can send it to you. I am unable to attach to a PM.

Keep in mind that when the car is running there is a different voltage seen on car vice when it is off. As it is regulating that voltage can be from 13.8 to 14.8 give or take .5vdc when the car is running. There is a voltage table in the tune to correct for voltage changes and how that effects your fuel injector pulse. If the voltage is higher or lower than the reference voltage the injector was tested at, it will compensate for that to make sure an accurate fuel amount is provided to the cylinder. If the tune can do this I would think that there would be an ability to correct for IAT as well IF line voltage can vary the IAT reference voltage signal by that much. I would think that the DC-DC regulator within the ECU would be able to correct for this down to a pretty low number and maintain an accurate 5.0vdc ref voltage without needing to compensate for voltage regulation changes from the charging system during normal operation.

Just out of curiosity did you buy direct from Edelbrock or did you buy through a distributor? If you bought through a distributor who does their own installs as well I would get them involved also because their credibility in service after the sale is potentially in question as well. They may have come across this during installs and can give you direct first hand 411 on the cause and what and who (if anyone) they worked with to resolve the issue. Just a thought.

 

[ugstang17]

This is all very interesting, because back when I was getting my P0113 CEL the explanation on the x4 was IAT2 high. I wonder if I’m getting correct IAT values when I pull the battery because it’s resetting to look at IAT, but then it sits overnight in the cold and the computer wakes up and is looking for but doesn’t see an IAT2?

The battery resetting it is a mystery. I don't know if adaptive learning is is part of this or if there is a default temp applied at startup before the IAT comes on line like happens with O2's before they go closed loop if you get my poor reference. The datalogger would/should give a window into this however.

 

[Jobodizo]

@ugstang17 once I finish typing this I'll pm you my email. Thank you!

I bought from the RDP store. No particular reason, they just had the best price.

I tried to call Finishline this morning but nobody answered. Guess it's a busy day for them.

I also heard back from Edelbrock tech this morning. They're running computer simulations with their tune department trying to figure out if they can replicate the issue. They did tell me that they only evaluated the sensor to 35*F and used that projected curve to interpret the signal. The curve obviously isn't linear, so it's possible that might affect something. Again, to your point, not sure why it would reset when I pulled the battery.

 

[Jobodizo]

Also, I made 2 small probes using arduino pin wires when I was reading resistance. The first 2 I made were accidentally male, instead of the female I needed for the MAF plug, so I can grab a voltage through the harness with little to no chance of a short. I can try doing that after I do the data log later tonight.

 

[ugstang17]

They open around 8ish. Kevin there takes the calls and may have had both lines lit up when you called. Give them a holler again.

I am not familiar with RDP. I see from their website they do tuning which would indicate that they also do installs. I 'd give them a ring as well. I am assuming you are referring to the place in Painsville.OH I found when i duckduckgo searched RDP right? They should be able to give you some direction if they have seen this as well.

 

[ugstang17]

Also, I made 2 small probes using arduino pin wires when I was reading resistance. The first 2 I made were accidentally male, instead of the female I needed for the MAF plug, so I can grab a voltage through the harness with little to no chance of a short. I can try doing that after I do the data log later tonight.

Sounds good.

 

[Jobodizo]

Ok, ran your configuration file @ugstang17:

Average battery voltage 11.01
Average IAT -1.97*C (28.5*F)
Average IAT voltage 4.87

Actual outside temp is 36*F

Cluster reads -74*F

 

[Nonsequitur]

Ok, ran your configuration file @ugstang17:

Average battery voltage 11.01
Average IAT -1.97*C (28.5*F)
Average IAT voltage 4.87

Actual outside temp is 36*F

Cluster reads -74*F

That battery voltage seems a bit low. Have you tried swapping out to a new battery to test? From my experience, low battery voltage sometimes contributes to inaccurate sensor readings.

 

[Jobodizo]

I plan on buying a new battery tomorrow after seeing that. In the past I have experienced the rear turn signal outer light issue because of a hard start. It tested ok last week, but it wasn’t 26* out last week, either.

 

[ugstang17]

I just collected some 411 on my car for you. OAT is about 28 here. KOEO display reads 18F voltage reads11.4vdc. Voltage on SCT X4 11.7vdc IAT 18F. Car has not been driven in a week. Started fine. Voltage on Car 14.7 vdc Voltage on SCT X4 14.84vdc IAT temp on car 18F same on SCT X4. Temps started climbing and reached 30F on display and SCT reads 29.67F. So they are the same. What I did notice is that the IAT refresh rate is not as frequent as on AFr bank1 or Lambse 1 which would make sense. The LCD display can lead or lag the SCT X4 by .5-1.0 degrees but nothing out of the ordinary. They do both seem to refresh at a similar rate just not simultaneously when the car is running. Keep in mind that the initial temp reading I provided was static with no heat being induced as the car had not yet been started.

One thing I noticed is that when I shut the car off and then went KOEO (engine not running) the LCD IAT temp stayed the same while the actual data on the hand SCT did update as it was absorbing heat from the engine. The LCD stayed at 34F and the IAT on the SCT climbed to 47F. So it appears that the IAT does not update when the car is not running possibly on the display though the data is present. Either that or I did not wait long enough for an update on the display to occur.

 

[ugstang17]

Ok, ran your configuration file @ugstang17:

Average battery voltage 11.01
Average IAT -1.97*C (28.5*F)
Average IAT voltage 4.87

Actual outside temp is 36*F

Cluster reads -74*F

Was this with the engine off? If so datalog next with engine running. Your not going to hurt anything. Have the datalogger running with KOEO and collecting data when you start it. This will allow us to see if the LCD display is just not updated and needs to update. Also note how the car starts. My car did not start rich and the IAT was well below what you were seeing in your data. I am also going to send you the standard CF4 that PBD uses for 15+ manuals. The IAT and battery voltage will be on that though IAT voltage will not. With what you have we can not be worried any longer with IAT volts. That is good IMHO.

 

[Jobodizo]

Interesting. So I guess what I need to do now is try and coax the car into starting while it’s reading at a ridiculous negative temperature to see whether or not the tuner sees more reasonable values. I would imagine that if the tuner shows the correct inlet air temperatures that would be the value from which the computer is making its running decisions? If it’s only an issue with the display, why didn’t the car want to start before?

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