40/41TE
AUTOMATIC 41TETRANSAXLE IDENTIFICATION
DESCRIPTION
The 41TE (Fig. 1) is a four-speed transaxle that is a conventional hydraulic/mechanical assembly with an integral differential, and is controlled with adaptive electronic controls and monitors. The hydraulic system of the transaxle consists of the transaxle fluid, fluid passages, hydraulic valves, and various line pressure control components. An input clutch assembly, which houses the underdrive, overdrive, and reverse clutches is used. It also utilizes separate holding clutches: 2nd/4th gear and Low/Reverse. The primary mechanical components of the transaxle consist of the following:
^ Three multiple disc input clutches
^ Two multiple disc holding clutches
^ Four hydraulic accumulators
^ Two planetary gear sets
^ Hydraulic oil pump
^ Valve body
^ Solenoid/Pressure switch assembly
^ Integral differential assembly
Control of the transaxle is accomplished by fully adaptive electronics. Optimum shift scheduling is accomplished through continuous real-time sensor feedback information provided to the Transmission Control Module (TCM).
The TCM is the heart of the electronic control system and relies on information from various direct and indirect inputs (sensors, switches, etc.) to determine driver demand and vehicle operating conditions. With this information, the TCM can calculate and perform timely and quality shifts through various output or control devices (solenoid pack, transmission control relay, etc.).
The TCM also performs certain self-diagnostic functions and provides comprehensive information (sensor data, DTC's, etc.) which is helpful in proper diagnosis and repair. This information can be viewed with the DRB scan tool.
The 41TE transaxle identification code is a series of digits printed on a bar-code label that is fixed to the transaxle case as shown in (Fig. 2).
For example, the identification code K 82111251316 can be broken down as follows:
^ K = Kokomo Transmission Plant
^ 821 = Last three digits of the transaxle part number
^ 1125 = Build date
^ 1316 = Build sequence number
If the tag is not legible or missing, the "PK" number, which is stamped into the transaxle case behind the transfer gear cover, can be referred to for identification. This number differs slightly in that it contains the entire transaxle part number, rather than the last three digits.
OPERATION
Transmission output is directed to an integral differential by a transfer gear system in the following input-to-output ratios:
First 2.84 : 1
Second 1.57 : 1
Third 1.00 : 1
Overdrive 0.69 : 1
Reverse 2.21 : 1
Torque Reduction Link
DESCRIPTION
The Torque Reduction Link (TRD) is a wire between the PCM and TCM that is used by the TCM to request torque management. Torque management controls or reduces torque output of the engine during certain shift sequences, reducing torque applied to the transaxle clutches.
OPERATION
The torque management signal is basically a 12-volt pull-up supplied by the PCM to the TCM over the Torque Reduction Link (TRD). Torque management is requested when the TCM pulses this signal to ground. The PCM recognizes this request and responds by retarding ignition timing, killing fuel injectors, etc. The PCM sends a confirmation of the request to the TCM via the communication bus. Torque reduction is not noticeable by the driver, and usually lasts for a very short period of time.
If the confirmation signal is not received by the TCM after two sequential request messages, a diagnostic trouble code will be set.