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Discussion Starter #1
Car in question is a 2007 5.7-liter Charger AHB (police package) which of course has the NAG1 W5A580 transmission. It is totally bone stock, unmodified, properly tuned up, no MILs, never beat on, serviced religiously, and it just turned 63,000 miles today. I've owned it since early 2010 at 29,900 miles.

The night before last, I went to accelerate from a stop. Engine revved to about 2500 RPM but I only made it to about 35 MPH, and very slowly at that. It almost felt like the transmission was slipping. Kept doing it the rest of the way to the facility. I tried to engage AutoStick just for the Heck of it (I never use it - its a column shifter). It turned on and displayed "5" in the usual place, but trying to change gear ranges with the up and down switches did nothing.

Not long after I arrived, I took the negative cable off of the battery and let it sit for a good 45 minutes to make sure everything was reset. Put the negative lead back on the battery, started it up, and drove it. Other than the ESP light being on while it was relearning stuff (I learned about that on here, thanks guys), it drove great. Seemed to shift normally and accelerated the way it usually does. Still no MILs. I didn't have my diagnostic tool with me at the time. Drove it home in the morning and it was fine then too. The only problem I had after power cycling was that the AutoStick would not turn on at all.

During the day yesterday, I connected up my diagnostic tool and checked for trouble codes. No trouble codes, no pending codes on either the engine or transmission. Still no MILs.

Last night, on the way to work, I was about halfway to the facility, and it did the same thing again. High revving, no acceleration, and throttle response was being limited in whatever gear it refused to shift out of. I couldn't tell if it was first or second. Didn't try AutoStick, but I had a feeling it wouldn't work. No MILs. When I got to the facility, I connected the diagnostic tool up and found that the transmission has a pending P2767 trouble code.

I did some research and found threads on LX Forums and Charger Forums by the same guy who had this same problem with his '07 Charger R/T at 64k miles back in 2010. The trouble code indicates one of the input speed sensors has no signal. So far, my problem has been intermittent.

The most I do on a transmission is drop a pan, change a filter, and refill ATF. I really don't feel like screwing this thing up, plus the car is still under warranty. It looks like the whole valve body has to be dropped out of the transmission to replace the sensor, and there's no telling if that's the actual problem or if its something else related to the sensor, maybe even the transmission control module. I'm figuring it will cost upwards of $800 for the repair at the dealer service department. My dealer can't get me in until July 26, so we'll see how it does until then. It drove fine after work this morning, probably put about 30 miles on it just today with no real troubles.

Has anybody else ever had this same problem? Did you get MILs on your instrument cluster or no? I find it interesting that it is "pending" the P2767 code, and not showing it as a full blown trouble code. Can anybody impart some knowledge on me?

Thanks a lot guys.
 

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P2767-Theory of Operation

The Input Speed Sensor 2 is one of two hall effect speed sensors that are used by the Transmission Control Module (TCM) to calculate the transmissions turbine speed. Since the turbine speed could not be measured directly, two of the drive elements are measured. Two input speed sensors are required because both elements are not active in all gears.

  • When Monitored:
    Engine speed greater than 450 RPM with none of the following DTCs present: engine speed, TCM undervoltage, output speed sensor, and/or rear wheel speed DTCs. Also required are all wheel speeds above 250 RPM and no wheel slip detected (signal from the ABS system).
  • Set Condition:
    If the Input Speed Sensor 2 signal is equal to 0 RPM.
POSSIBLE CAUSES:

SENSOR SUPPLY VOLTAGE CIRCUIT OPEN INPUT SPEED SENSOR 2 SIGNAL CIRCUIT OPEN
SPEED SENSOR 2 SIGNAL CIRCUIT SHORT TO ANOTHER CIRCUIT SENSOR GROUND CIRCUIT OPEN SENSOR GROUND CIRCUIT SHORT TO ANOTHER CIRCUIT SPEED SENSOR 2 SIGNAL CIRCUIT SHORT TO GROUND SENSOR GROUND CIRCUIT SHORT TO GROUND INPUT SPEED SENSOR 2 TRANSMISSION CONTROL MODULE
 

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Discussion Starter #3
Yeah, I found the PDF version of that linked to on one of the other forums.

Since this thing is under warranty, I opted to have the dealer service department do this repair. I took it in yesterday morning and it was done by this afternoon. They replaced the electrohydraulic control unit, 52108308AC.

Even though dropping the valve body was necessary to do the job, which obviously means dropping the pan and replacing the fluid (and also changing the filter and a new gasket for anybody with half a brain) the warranty company tried to be cheap. First they said they weren't going to cover anything at all. Then, after I called them up and reminded them that their original paperwork said that they specifically covered transmission internals, solenoids, and sensors, they decided to start a claim. They ended up paying $274.64 of the total $636.95. Better than nothing, but pretty much a warranty with that kind of coverage was a big waste of money for me. That's the last time I spend any extra money on any kind of an extended warranty.
 

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Dealing with aftermarket warranty service contract companies can be as frustrating as dealing with an insurance company. Many times they will try to deny coverage right up front. I'm glad you got it fixed.
 
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