Check engine light is on and i'm throwing code P0734. What is causing it?

looking it up online it says "4th gear incorrect ratio"

I still have all of my gears, but it wont shift until the RPMs come up to around 3500-4000rpm. (guessing this is "limp" mode that its running in)

Dodge dealer wants $90 to tell me what is wrong.
its a 1998 dodge ram 360 with auto btw

Any ideas?

 

are you sure that is the code. i dont list a P0734.

 

I don't know much about the tranny, but thisis what I could find for you.


P0734-GEAR RATIO ERROR IN 4TH

When Monitored: The Transmission gear ratio is monitored continuously while the Transmission is in gear.

Set Condition: If the ratio of the Input RPM to the Output RPM does not match the
current gear ratio.

Theory of operation: The transmission system uses two speed sensors, one to measure input RPM and one to measure output RPM. These inputs are essential for proper transmission operation. Therefore, the integrity of this data is verified through the following checks:
1. When in gear, if the gear ratio does not compare to a known gear ratio, the corresponding in-gear trouble code is set (codes 50 through 54).
2. An excessive change in input or output speeds indicating signal intermittent will result in codes 56 and/or 57 being set.
3. After a PCM reset in neutral, observing erratic output and input speed sensor signals indicates a loss of the common speed sensors ground. This
sets a code 58.

Transmission Effects: The transmission will not go into Limp-in mode until three gear ratio error events occur in a given key start also the MIL will illuminate after 5 minutes of substituted operation. This allows for intermittent problems to correct themselves without opening the relay. However, if a gear ratio error develops, a code is always set, but if the condition corrects itself the transmission will continue without requiring the ignition key to be cycled on and off.

POSSIBLE CAUSES
> If code P0944(35) is also set, follow diagnostic procedure for code P0944(35) first
> Failed or slipping OD clutch - may also set code P0733(53)
> OD and Reverse inner and outer lip seal leakage (usually hard code)
> Sticky OD accumulator seals (intermittent)
> Worn reaction shaft support seal rings (hard code at heavy throttle)
> Broken OD/UD tapered snap ring - (hard code at heavy throttle)
> Failed or slipping 2/4 clutch - may also set code P0732(52)
> 2/4 seal leakage (intermittent)
> Sticky accumulator seals (intermittent)



Hope it helps. Doesn't look like good news though.

 

zman, where did you find that?

 

OMG! I can't find it now, wtf! LOL All I did was search for "p0734 code dodge ram".

 

I'm sorry, I simply can't find the site. And like an idiot I didn't bookmark it.

 

lmao, the mystery of the vanishing DTC sheet.

 

thank you for the info, I found a page similar to that somewhere but it didn't have all that info. I still dont understand what to do to correct it. where are these sensors located? maybe i can start by checking the leads on those.

 

One on the top of the rear end is a common prob, but usually set off abs and brake light.

 

For anyone else that runs into this trouble code, output speed sensor solved it.