hot outside temps causing transmission to act weird

orbanator7577 · **Posted:** Thu Sep 12, 2013 10:37 am

Here is an interesting issue I have. In the morning I drive to work and it drives like a dream 26 miles to work. I go to lunch, it drives fine. At the end of the day when it is usually the hottest outside, the transmission goes in to limp mode about half way home. This only happens when it is in the 90+ temps outside, otherwise no issues.
In hopes to fix this, I have replaced the fluid, filters, solenoid pack, and TCM. I even added a transmission cooler thinking the tranny was running hot.

I feel like it is a sensor that has gone bad and acts up when hot outside.

Any ideas?

Hexus · **Posted:** Thu Sep 12, 2013 10:51 am

Replace both sensors.

Part #4799061AB
[Yes, they are both the same part number]

orbanator7577 · **Posted:** Thu Sep 12, 2013 11:01 am

When I got the jeep last September, I replaced the sensors. You think the heat is causing one of them to go out of range?

Hexus · **Posted:** Thu Sep 12, 2013 11:32 am

Well, I would say that it's possible. It's also possible that the solenoid pack you got is malfunctioning, I know the people that sold me mine at Transtar said it wouldn't have been the first if it wasn't working right out of the box.

I know that's something you don't want to hear, but it's possible.

You got a limp mode without a CEL? That may not be a transmission issue at all, it may be an air-in-fuel issue.

Typically if something in the Transmission particularly is faulty it will trip a CEL, because there are TONS of sensors and electronics down there.

Scan your OBD-II for codes, if you get nothing then I would say it might be an air in fuel issue, it manifests with heat and will cause limp mode.

Possible fixes if it is an air-in-fuel problem would be to install a lift pump (easiest probably) or check all the fuel lines and replace them with their connections (nightmare).

orbanator7577 · **Posted:** Thu Sep 12, 2013 11:52 am

I replaced the solenoid pack a week ago and it has been shifting great. Yesterday was the first time in a week it has been over 90 and it started acting up again. I checked and my obd scanner says p0700. I would only get 2nd & 3rd gears. Overdrive would work sorta and then slam in to third. I have to drive home with overdrive off.

The engine hasn't gone in to limp mode since I replaced the injectors and has been running great. Always starts on the first crank and I have tons of power.

These problems only happen when it is hot outside and I make right turns. Otherwise it drives really nice when the outside temps are below 90°.

Weird right?

Hexus · **Posted:** Thu Sep 12, 2013 12:16 pm

If you are getting P0700 that is the generic fault code for Transmission problems.

Did you add fluid until the dipstick showed full? IF you did, you have too little fluid in there, because our dipstick is too long for the tube and transmission pan.

Secondly, you need to take your Jeep to a Transmission shop or a dealership to nail down the Transmission codes, because a regular OBD-II scanner will only show the P0700 and not the definitive codes invovled with the fault.

Most reputable Transmission shops will scan it for free, don't even try Auto-Zone or the like, their scanners will not work.

You need to find out what code your transmission is giving, sooner = better.

SENT · **Posted:** Thu Sep 12, 2013 4:37 pm

Is the transmission works propertly some time after you turn off the engine and turn on it back?

hot outside temps causing transmission to act weird

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