Page 61
Ph: 804.227.3023
10511 Old Ridge Rd. Ashland, VA 23005
4LHD/4LHDX Application Manual
Powertrain Control Solutions
REV 1.1
2.5 TCM Interface
The PCS 4LHD/4LHDX uses an electro-hydraulic control system to control shift pattern, line pressure, torque converter
clutch operation and transmission diagnostic actions. The electronic control system consists of inputs and outputs to the
control module. Inputs are dened as sensors and signals that monitor engine and transmission performance. Outputs
are signals to request the engine controller to modify engine torque during specic transmission shift and stall conditions.
It may also request increased idle speeds at elevated temperatures.
2.5.1 TCM Overview
TCM Handling
The following considerations should be adhered to when handling PCS transmission control module (TCM):
• Any TCM displaying visible damage shall not be installed in a vehicle.
• TCM enclosures shall not be opened by vehicle assembly personnel, and only on a case to case basis.
• Electrostatic discharge prevention techniques shall be employed by vehicle assembly personnel when handling
the TCM.
• PCS and the customer shall work together to dene the TCM programming.
• To properly install and uninstall the TCM2600 or TCM2800 connector, reference the MX123 Connection System
User Manual which can be found online. This is critical to prevent pin damage. For other TCMs, reference their
respective PCS TCM manuals.
TCM Installation
TCM mounting location denition, mounting bracket design, sourcing, validation, and vehicle assembly process
are all the responsibility of the customer.
If the vehicle will be subjected to electrical welding procedures (e.g. during body building assembly process) the
harness and TCM must be electrically isolated (removed) from the vehicle. Wire gage between the transmission,
TCM, and other vehicle systems shall comprehend the distances between components to minimize voltage
drop and signal degradation. The electrical supply for other electrical devices such as remote starters, alarm
systems, communication systems, etc. shall not interfere with the TCM voltage requirements. Reference the PCS
4LHD/4LHDX Technician’s Guide for more information.
Operating and Storage Temperature
Operating and storage temperature capabilities depend on control module design. PCS and the customer must
agree upon applicable TCM storage and operating temperature specications.
Generally, control modules may be stored between -40°C and 125°C.
Typical operating temperatures range from -40°C to 85°C for passenger compartment mounted TCMs and from
-40°C to 105°C for under the hood mounting locations.
The customer is responsible for meeting the agreed temperature limitations. PCS offers a bracket kit to mount the
TCM on the transmission case. Reference Figure 2.5.2-1 and the PCS OEM Parts Catalog for more information.
To Next Page
Loading...
Need help?
General