P0732 and P0733 CRD 545RFE after new tires installed?

Silverdiesel · **Posted:** Mon Dec 17, 2007 9:28 pm

Can new tires affec or be the cause of "Incorrect gear ratio" that these two codes are saying.
Went from 225/75/16- 29.3" tall to 235/70/16- 29.6" tall.
Or are these codes from something else.
Can I reboot ECM/TCM to "learn" again? I can use any help.

gmctd · **Posted:** Mon Dec 17, 2007 9:35 pm

What were local ambient temps, and was the vehicle stone cold?

Silverdiesel · **Posted:** Mon Dec 17, 2007 9:44 pm

Nope-- warmed up -- outside temp- 50 degrees-- Lots of slipping and then a thump into the next gear-- The truck has all the F's (31,37) done on it but all the trans is still DC stock.

gmctd · **Posted:** Mon Dec 17, 2007 9:55 pm

That sounds serious - does it do that every time you take off, or just that first time?

Silverdiesel · **Posted:** Mon Dec 17, 2007 10:00 pm

Ummm-- Every time- I had recently changed fluid/pancake and spin on filter-- and it was a tad low -- brought it up to just under "hot" level at normal operating temp and slipping/ thumping did ease a bit- but it it still there. Did a battery disc so computers can learn again also.

gmctd · **Posted:** Mon Dec 17, 2007 10:48 pm

That doesn't even come close to enuff difference in diameter or width to effect a change in TCM control or transmission response

Switch O\D off, try taking off in Low, use shifter to move to Second, then Third, then Fourth - see if it's firmer or any continued delay

Endurance · **Posted:** Tue Dec 18, 2007 12:24 am

Are you still using the original TC? If no, how many miles does the current one have? Sounds like a bad TC to me.

Joe Romas · **Posted:** Tue Dec 18, 2007 9:13 am

On your error code. The 06 models have a speed sensor on the differential along with the wheel sensors. I wouldn't have any idea if the tire change was enough to cause your problem. It sounds like you have some type of transmission problem also. Since the filters were recently replaced is it possible a seal was pinched or whatever happenes to them on installation :?:

Joe

retmil46 · **Posted:** Tue Dec 18, 2007 3:03 pm

gmctd wrote:

That doesn't even come close to enuff difference in diameter or width to effect a change in TCM control or transmission response

Switch O\D off, try taking off in Low, use shifter to move to Second, then Third, then Fourth - see if it's firmer or any continued delay

Agreed. I haven't heard of anyone having this problem just from swapping tire sizes, even when adding a lift and a considerable difference in size.

Just did the swap to 245/70's recently myself, no difference noticeable.

Speed sensor works off the gears in the diff - all a considerable difference in size would do is throw off the accuracy of the odometer and speedometer.

Definitely sounds like this is tranny related, the fact that it's noticeable just after swapping tire sizes is most likely pure coincidence.

scrambledKJ · **Posted:** Tue Dec 18, 2007 5:44 pm

I haven't seen any codes and I am running 235/70 up front and 245/75 in the rear. I know it looks a litte silly, but the 245 BFG are great with a trailer attached. I have 2 more for the front, but have to spend a day and put the lift that's in the basement on.

Travis

onthehunt · **Posted:** Tue Dec 18, 2007 8:17 pm

Quote:

haven't seen any codes and I am running 235/70 up front and 245/75 in the rear. I know it looks a litte silly, but the 245 BFG are great with a trailer attached. I have 2 more for the front, but have to spend a day and put the lift that's in the basement on.

Travis

Hope you don't use 4-wheel drive with two diff. size tires on. Not a good thing.

Silverdiesel · **Posted:** Wed Dec 19, 2007 12:35 am

You know, I think it is more of a trans problem--maybe the new fluid involved in the filter change has yet to get up to all the gaps and voids. I am at 10 quarts ATF+4 at refill and have yet to measure to the two hole marks for "hot level" on the stick. This fluid check is made when the Jeep is fully warmed up (right after getting of the highway). Don't these transmissions take a total of 17 quarts or so? I am aware not all the fluid drains out when the pan is dropped. The magnet in the pan was suprisingly clean.
And- I am on the stock TC (I assume it is one of the replacement parts of the F37 campaign update).
The F37 was done before I bought the Jeep at 19K and now it is at 30K miles. The trans fluid service was done by me as part of the 30K service.
Thanks for responding and I will add fluid to between those two holes "hot level"and see if will quit slipping thumping at shifts.

Joe Romas · **Posted:** Wed Dec 19, 2007 8:59 am

When the F-37's were being done the documentation listed a incorrect amount of fluid and many owners were sent packing low on fluid and had shifting problems. This transmission is very sensative to the correct fluid level :shock:

The cold fill marks are only a starting point so get it good and warm and adjust the level to between the 2 hot marks. Since it's adaptive it may take it a while to relearn. One problem that f-37 brought out was the need to do a quick adaptation (not totally sure that's the correct term) of the TCM for better operation so removing the battery cables to reset the TCM might help also

P0732 and P0733 CRD 545RFE after new tires installed?

Who is online