After my engine swap I've had code p0073, ambient air temperature sensor circtuit high.

-external temps stay at -40
-fromt blinkers do not work, it sounds normal for 9 cycles and at the 10th its a rapid click, which makes the rear blinkers rapid click too.
-I replaced the sensor
-I replaced a front blinker that was burnt out
-I took the TIPM off and no wires are severed. No wires to the blinkers are compromised.
-checked grounds

I'm at a loss. What else is there?

 

2012 JK, right? Swap with another 3.6L? Pretty sure you didn't swap it with a 3.8L, but maybe a 5.7L Hemi? Maybe a 2.8L Diesel? Other?

Assuming like-for-like on the swap, P0073 Possible Causes:AAT SIGNAL CIRCUIT SHORTED TO VOLTAGE

AAT SIGNAL CIRCUIT OPEN/HIGH RESISTANCE

AAT SENSOR GROUND CIRCUIT OPEN/HIGH RESISTANCE

AMBIENT AIR TEMPERATURE (AAT) SENSOR

TOTALLY INTEGRATED POWER MODULE (TIPM)

Both wires from the TIPM go straight to the AAT sensor, so there is no other place to look. If I had to pick, the ATT signal is shorted to voltage somewhere. Likely to the front blinkers since they are bonkers too.

Step 1: The first thing I'd try is to disconnect the AAT sensor and see if the weird blinker stuff goes away. If it does, you might consider going straight to Step 3. But it might be worthwhile to verify the TIPM anyway, so...

Step 2: The voltage at the ATT sensor Pin 1 should be <4.98 vdc when the sensor is connected and ignition on but engine not running. The easiest way to test the TIPM voltage i.s with an OBD2 reader and an app like AlphOBD. Select the Central Gateway Module. You should be able to find Ambient Temperature voltage a bit down the list. Then disconnect the sensor and short the pins together on the chassis-side connector. It should read <1.0vdc. If that all works, your wiring and TIPM are good and there are no shorts to voltage. But since you already replaced your ATT sensor there's probably something a bit more sinister going on.

Step 3: Disconnect the C4 connector from the TIPM and disconnect the AAT sensor connector. With ignition on and engine not running, measure the voltage on the chassis side of the AAT connector. If any voltage is present, you have a short to voltage.

Step 4: From there you descend into the depths of troubleshooting shorted wire gremlins. At this point I usually concede to the gremlins and just replace the offending wire. That would be especially true if your weird blinker issue goes away in Step 1.

Let us know how things work out!

 

Removed the sensor and blinkers are still weird.

With the ignition on, the harness is getting no power. Unsure if that's how you recommended testing.

 

Well, that pretty much rules out a short to voltage in the wiring.

Did you verify the sensor voltage at the TIPM via an OBD2 reader? With the sensor in mine reads about 2.5vdc in the AlfaOBD data.

The next step would be to test the sensor wire continuity. First, with ignition off, disconnect the AAT sensor and measure chassis-side pin 2 to ground. It should read about 0 ohms.

If that's good, then disconnect the C4 connector from the TIPM and check continuity between Pin 1 of the AAT sensor to Pin 15 of C4, and P2 to Pin 14. They should read about 0 ohms. If any of these fail you have an open wire.

Here's where to look:












If the wiring is good, it looks like it's a problem in the TIPM.

Do you have LED bulbs in the turn signals? That can cause hyperflash. The other possibility is the turn signal relay could be bad. That wouldn't be related to the AAT sensor failure, just a coincidence.

 

thanks for the diagram. I'll do what I can. I hate electronics in vehicles! I'm more of a wrench person.

I thought we didn't have turn signal relays and all, thought it was all built in.

 

The relay is probably not the cause of the erratic flash. Its sole purpose is to make that blinker "click" we all know and love. It could be loading down the blinker circuit, but even if it was, it's not practical to replace it as it's soldered onto the instrument panel electronics board.

I'm leaning toward the TIPM being bad.

 

Wouldn it be dumb to buy a tipm and just test it out...i absolutely hate wiring. I imagine a auto electric mechanic will charge a lot for just diagnosing, maybe the price of a tipm. Used or remanufactured at least. I'm going to do my best with your diagram first.

Nevermind theyre pricey lol

 

I dont have a Bluetooth smart obd2 reader, but i have a fancier plug in one that can do live data and abs/srs codes. Might that work?

 

Give it a try! The hard part will be locating the AAT sensor voltage. It's a standard SAE J1979 (OBD2 protocol) PID. Depending on your unit you might just find spelled out as "Ambient Temperature" or similar. If your unit asks for a PID, try 46 (Hex) or 70 (decimal). The standard is in °C so you might not see voltage but rather a range of -40 to 215. Max cold is max voltage, around 5vdc or greater.

The circuit works by supplying a reference voltage, usually around 5vdc. The AAT has a temperature-sensitive resistor (thermistor) that has maximum resistance at -40 and slowly decreases as the temperature rises. Maximum resistance to ground means that the reference voltage is higher. As things warm up the resistance decreases and the voltage drops.

The fault code you are getting says the AAT is failing with the circuit high. That tells me that there is an open somewhere between the TIPM supplying the reference voltage and the thermistor, so the monitor on the voltage is saying it's maxed out (or really, beyond maxed out) so it looks like the thermistor is reading -40, or maximum resistance. Actually, there is infinite resistance if it is indeed an open circuit.

Odds are it's an open in the TIPM. It's not a short to ground as the temperature would read 215, or 0 volts, at the TIPM monitor. Or it could be a problem somewhere downstream. I would consider the OBD2 reader just a sanity check to make sure nothing else is missed. Check pins 14 and 15 on the TIPM connector, both sides, It could be a pushed or bent pin. If you measured continuity on Pin 15 to Pin 1 of the AAT connector, it's likely pushed on the C4 connector at the TIPM. You might get real lucky and be able to pull the pin back out with a pair of needle-nose pliers, or if bent straighten it out with a small flat-head screwdriver. If you don't see anything wrong with the pins, then the fault is internal to the TIPM.

Hope you don't mind the long explanation. I'm the type that likes to figure out how things work as much as possible. Comes in handy for other similar issues.

 

I dont mind it at all. I juat need to process it in my own way lol want to donthe tests properly

Hope this little reader can help out. It's been great for all my vehicles so far