Sep 282016
 

2003 Dodge RamMy 2003 Dodge Ram 2500, 5.9L Cummins 4×4 has a 48re auto transmission. When I put it into drive I feel it go in and sometimes everything is fine. Other times the truck will barley move until it gets up to speed(15 mph) and shifts into 2nd then its all good. My question is, is this internal or a solenoid going bad. The truck sat for a couple of months while I recovered from surgery but before that everything was fine…


RESPONSE

Checking the transmission fluid level and color will give you the answer to your question. If the color of the fluid is pretty redish/pink than it would be a sensor/solenoid issue. You may have codes stored. If the color is dark or burnt, there is an internal issue that may require a rebuild. And of course if the fluid level is low, topping it off and testing would be prevalent.

Transmission Diagnostic Trouble Codes

Diagnostic trouble codes (DTC’s) are codes stored by the Transmission Control Module (TCM) that help us diagnose Transmission problems. They are viewed using the DRBIII® scan tool.

Always begin by performing a visual inspection of the wiring, connectors, cooler lines and the transmission. Any obvious wiring problems or leaks should be repaired prior to performing any diagnostic test procedures. Some engine driveability problems can be misinterpreted as a transmission problem. Ensure that the engine is running properly and that no PCM DTC’s are present that could cause a transmission complaint.

If there is a communication bus problem, trouble codes will not be accessible until the problem is fixed. The DRBIII® will display an appropriate message. The following is a possible list of causes for a bus problem:

  • open or short to ground/battery in PCI bus circuit.
  • internal failure of any module or component on the bus

Each transmission diagnostic trouble code is diagnosed by following a specific testing sequence. The diagnostic test procedures contain step-by-step instructions for determining the cause of a transmission diagnostic trouble code. Possible sources of the code are checked and eliminated one by one. It is not necessary to perform all of the tests in this book to diagnose an individual code. These tests are based on the problem being present at the time that the test is run.

If the TCM records a DTC that will adversely affect vehicle emissions, it will request (via the communication bus) that the PCM illuminate the Malfunction Indicator Lamp (MIL). Although these DTC’s will be stored in the TCM immediately as a 1 trip failure, it may take up to five minutes of accumulated trouble confirmation to set the DTC and illuminate the MIL. Three consecutive successful OBDII/EURO III trips or clearing the DTC’s with a diagnostic tool (DRBIII® or equivalent) is required to extinguish the MIL. When the TCM requests that the PCM illuminate the MIL, the PCM sets a DTC ($89) to alert the technician that there are DTC’s in the TCM. This must also be erased in the PCM in order to extinguish the MIL.

HARD CODE

Any Diagnostic Trouble Code (DTC) that is set whenever the system or component is monitored is a HARD code. This means that the problem is there every time the TCM checks that system or component. Some codes will set immediately at start up and others will require a road test under specific

conditions. It must be determined if a code is repeatable (Hard) or intermittent before attempting diagnosis.

ONE TRIP FAILURES

A One Trip Failure, when read from the TCM, is a hard OBDII/EURO III code that has not matured to the full 5 minutes. This DTC can take up to five minutes of problem identification before illuminating the MIL

INTERMITTENT CODE

A diagnostic trouble code that is not there every time the TCM checks the circuit or function is an intermittent code. Some intermittent codes, such as codes are caused by wiring or connector problems. However intermittent Speed ratio codes are usually caused by intermittent hydraulic seal leakage in the clutch and/or accumulator circuits. Intermittent speed ratio codes can be set by intermittent speed sensor circuitry or by line noise being induced onto one or both of the speed sensor signal circuits. Problems that come and go like this are the most difficult to diagnose, they must be looked for under the specific conditions that cause them.

STARTS SINCE SET COUNTER

The Starts Since Set counter counts the number of times the vehicle has started since the most recent DTC was set. The counter will count up to 255 starts. Note that this counter only applies to the last code set.

When there are no diagnostic trouble codes stored in memory, the DRBIII® will display NO DTC’s PRESENT and the reset counter will show STARTS SINCE CLEAR = XXX.

The number of starts helps determine if the diagnostic trouble code is hard or intermittent.

  • If the number of starts is less than 3, the code is usually a hard code.
  • If the number of starts is greater than 3, it is considered an intermittent code. This means that the engine has been started most of the time without the code recurring.

TRANSMISSION TROUBLE CODE ERASURE

A Diagnostic trouble code will be cleared from TCM memory if it has not reset for 40 warm-up cycles.

A warm-up cycle is defined as sufficient vehicle operation such that the coolant temperature has risen by at least 22° C (40° F) from engine starting and reaches a minimum temperature of 71° C (160° F).

The Malfunction Indicator Lamp (MIL) will turn off after 3 good trips or when the DTC’s are cleared from the TCM.

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