Tranny not responding!

[rncummins]

To whom that might be able to help. My Problem is the trans is not talking to the pcm (I think), When I put it in gear the trans shifts into gear but will not shift to any other gear, the indicator (PRND321) the circle around the gear is not showing up, its there when in (P)and (N) but when I put it in gear it doesnt show up ??????????Any info will be GREATLY APPRECIATED !!! I did have dealer ship scan and they said that the pcm was not registering , as if its not in the truck.:banghead:

[Mopar1973Man]

Welcome to the family Robbie..

But I'm not exactly clear on what going on here... The indicator on the dash is just a cable driven pointer.

GEAR SELECTOR INDICATOR OPERATION

The mechanical gear selector indicator gives an indication of the transmission gear that has been selected with the automatic transmission gear selector lever. A red pointer appears in a window below the character in the indicator representing the transmission gear that has been selected. The small, spring-loaded pointer moves on a track through a trolley-like mechanism within the indicator housing. A short length of small diameter stranded cable is

attached to one side of the pointer trolley and is encased in a tubular plastic housing that exits the right side of the indicator. The cable is routed through the instrument panel and under the steering column to the left side of the column. The looped end of the cable is hooked over the end of the PRNDL driver lever on the steering column gearshift mechanism, and the cable housing is secured in a molded plastic adjuster and bracket on the column housing. When the gear selector lever is moved the PRNDL driver lever moves, which moves the pointer through the mechanical actuator cable. The cable adjuster and bracket unit mounted on the steering column housing provides a mechanical means of calibrating the gear selector indicator mechanism.

[Wild and Free]

Welcome to the family Robbie..

But I'm not exactly clear on what going on here... The indicator on the dash is just a cable driven pointer.

GEAR SELECTOR INDICATOR OPERATION

The mechanical gear selector indicator gives an indication of the transmission gear that has been selected with the automatic transmission gear selector lever. A red pointer appears in a window below the character in the indicator representing the transmission gear that has been selected. The small, spring-loaded pointer moves on a track through a trolley-like mechanism within the indicator housing. A short length of small diameter stranded cable is

attached to one side of the pointer trolley and is encased in a tubular plastic housing that exits the right side of the indicator. The cable is routed through the instrument panel and under the steering column to the left side of the column. The looped end of the cable is hooked over the end of the PRNDL driver lever on the steering column gearshift mechanism, and the cable housing is secured in a molded plastic adjuster and bracket on the column housing. When the gear selector lever is moved the PRNDL driver lever moves, which moves the pointer through the mechanical actuator cable. The cable adjuster and bracket unit mounted on the steering column housing provides a mechanical means of calibrating the gear selector indicator mechanism.

Not so fast Mike, he has no info on what year rig he has here, the 3rd gens have a digital display.

Edit> I need to appologize and correct myself here all 2nd gen do have mechanical indicators like Mike stated and his procedure would be correct, I had a pre coffe brain fart.

[Mopar1973Man]

I didn't know that... :banghead:

I guess your going to have to help him...

Ok looking towards the 2003 factory service manual to try and fill in again... I don't know if both systems are the same.

OPERATION

The electronic gear selector indicator gives an indication

to the vehicle operator of the transmission

gear that has been selected with the automatic transmission

gear selector lever. This indicator is controlled

by the instrument cluster circuit board based

upon cluster programming. The cluster circuitry

automatically configures itself for the proper transmission

and automatic transmission model based

upon the hard wired transmission range sensor mux

circuit input to the cluster. The gear selector indicator

information is displayed by a dedicated Vacuum

Fluorescent Display (VFD) unit on the instrument

cluster electronic circuit board, and the VFD will not

display the gear selector indicator information after

the ignition switch is turned to the Off position. The

instrument cluster circuitry configures the gear selector

indicator VFD based upon the following inputs

from the transmission range sensor:

Open Circuit - If the cluster is configured for

an automatic transmission and the transmission

range sensor mux circuit is open, the cluster circuitry

controls the gear selector indicator display based

upon electronic messages received from the electronic

Transmission Control Module (TCM) over the Programmable

Communications Interface (PCI) data

bus. If the transmission range sensor mux circuit is

open and no electronic messages are received from

the TCM within two seconds, the instrument cluster

circuitry will not display any gear selector position

until the condition is resolved or until the ignition

switch is turned to the Off position, whichever occurs

first.

Resolved Circuit - If the transmission range

sensor mux circuit is resolved, the cluster circuitry

controls the gear selector indicator display based

upon the resistance value of the hard wired input

from the transmission range sensor. If the cluster is

configured for an automatic transmission with a

transmission range sensor input and detects a short

to ground or an open in the transmission range sensor

mux input, the instrument cluster circuitry will

not display any gear selector position in the VFD.

The VFD display for the short-to-ground and open

circuit conditions will continue until the condition is

resolved or until the ignition switch is turned to the

Off position, whichever occurs first.

Actuator Test - Each time the cluster is put

through the actuator test, the gear selector indicator

VFD will display all of its characters at once during

the VFD portion of the test to confirm the functionality

of the VFD and the cluster control circuitry.

On models with a TCM, the TCM continually monitors

the transmission range sensor, then sends the

proper gear selector indicator position messages to

the instrument cluster. On models without a TCM,

the instrument cluster continually monitors the hard

wired transmission range sensor multiplexed input.

For further diagnosis of the gear selector indicator or

the instrument cluster circuitry that controls this

function, (Refer to 8 - ELECTRICAL/INSTRUMENT

CLUSTER - DIAGNOSIS AND TESTING). For further

diagnosis of the transmission range sensor on

models without a TCM, (Refer to 21 - TRANSMISSION/

TRANSAXLE/AUTOMATIC - 42RE/TRANSMISSION

RANGE SENSOR - DIAGNOSIS AND

TESTING) or (Refer to 21 - TRANSMISSION/

TRANSAXLE/AUTOMATIC - 46RE/TRANSMISSION

RANGE SENSOR - DIAGNOSIS AND TESTING).

On models with a TCM, for proper diagnosis of the

transmission range sensor, the TCM, the PCI data

bus, or the electronic message inputs to the instrument

cluster that control the gear selector indicator,

a DRBIIIt scan tool is required. Refer to the appropriate

diagnostic information.

[Wild and Free]

I have to appologize here I edited my prior post. The 2nd gens are mechanical and Mike is correct in checking and adjusting them, the 3rd gens are digital/electronic.

[Mopar1973Man]

Ok... We all have off days...Worse yet its in the Common Rail froum so your still right...I guess we need the OP to fill out his signature so we both stop guessing at it...

[rncummins]

Thank you for putting up this forum its awsome !! Sorry for not posting more info on my truck. I have an '03 (manufactured date 05/03) it has 112k miles 4x4.

My PROBLEM is The indicator shows the circle around P and N but it does'nt show up when I put it in R D321 but you can feel the trans go on gear . I've replaced govenor pressure sensor and silenoid, fluid, filter then took it to the local dealership and they put it on a hand held computer and said the PCM was not responding at all so he unpluged a couple of sensors and plugged them back in and still no response to his computer so I replaced the PCM and it still doing the same thing. So I'm lost is there a seperate comp for the trans or is it possible the gage cluster is not sending the messasge that its in gear ? Thank you all for the info!!!

--- Update to the previous post...

Ok... We all have off days...

Worse yet its in the Common Rail froum so your still right...

I guess we need the OP to fill out his signature so we both stop guessing at it...

How do I fill out my signature ? I would be happy to put it on here but I don't know where to add that info.

[Mopar1973Man]

Thank you for putting up this forum its awsome !! Sorry for not posting more info on my truck. I have an '03 (manufactured date 05/03) it has 112k miles 4x4.

My PROBLEM is The indicator shows the circle around P and N but it does'nt show up when I put it in R D321 but you can feel the trans go on gear . I've replaced govenor pressure sensor and silenoid, fluid, filter then took it to the local dealership and they put it on a hand held computer and said the PCM was not responding at all so he unpluged a couple of sensors and plugged them back in and still no response to his computer so I replaced the PCM and it still doing the same thing. So I'm lost is there a seperate comp for the trans or is it possible the gage cluster is not sending the messasge that its in gear ? Thank you all for the info!!!

--- Update to the previous post...

How do I fill out my signature ? I would be happy to put it on here but I don't know where to add that info.

Ok... As for the signature that's easy... Just go up top and hit the User Control Panel -> Edit Signature...

Normally there is a 20 post restriction on the download area so I upgraded you access so you can access the 03 Factory Service Manual for you truck...

http://forum.mopar1973man.com/downloads.php?do=file&id=189

I'm pretty sure there is another tranny controller but this book should help a bunch.