I just purchased this truck about a month ago. It has 44K on it now. 2006 2500 hemi with the 545rfe transmission. Today I drove it about 10 miles, parked it for about an hour. I went to take off and it would not shift down from 3rd. I shifted manually to 1st however it just shifted down to 2nd. I cannot get it to go to first gear. I have no overdrive either.

It threw a check engine light, however I've tried the Key trick to pull the codes and it does not seem to work. Help anyone?

 

Finally got it to pull the code P700 :

P0700-TRANSMISSION CONTROL SYSTEM (MIL REQUEST)
WHEN MONITORED:

Ignition on and battery voltage

SET CONDITION:

An active DTC is stored in the TCM. One Trip Fault. Three good trips to turn off the MIL.

POSSIBLE CAUSES

- DTC present in the transmission control module

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding.

 

Sounds like a syncho problem... but thats only in standard trannies isnt it?

 

Charge the battery up and reboot to see if it helps.

 

Sounds like the transmission is in limp mode. If the battery charging and reconnecting doesn't work you may have to take it to the dealer. Sometimes they have to hook up to the computer and install updates/fixes for the computer.

 

Yeah I agree it sounds like it is in Limp mode. Sounds exactly like what my sons GMC was doing a whle back, I changed out the Control Module to fix it.

 

being as you only have the P0700 code its most likely just a computer/sensor problem. if you were throwing like a P0731-P0735 it would most likely be a mechanical problem. if after clearing the code, it still comes back, try getting your pcm/tcm reflashed.

 

I decided to take the truck to the dealership. They called today and informed me that it needed a new PCM. They ordered it and will be installed tomorrow. We'll see if it fixes it!

 

Keep us informed

 

Got the truck back today. They pulled the following codes from the transmission:
P0846 P0871 P0988 P0876 P0869 P0882

I looked up each code and under all of them it lists the power control module as a possible suspect. It seems at this point that it is fixed.

Cost to replace: $0.00 Woo Hoo!!!!

Parts Covered for 8 years or 80,000 miles

If your truck has one of the following parts, this
Federal Emission Warranty covers that part for a
period of 8 years or 80,000 miles, whichever occurs
first.
These limits are counted from the time when
your Basic Limited Warranty begins under
2.1(E). The covered parts are:
• catalytic converter; and

• powertrain control module.