Automatic transmission system relies on various measurement
data to determine the current control status and extrapolate the
necessary compensation values. These values are used to control the
actuators and achieve the desired control output. If a problem with the
drivetrain, including the transmission, has been identified, perform
self-diagnosis and basic transmission inspection (oil and fluid
inspection) and then check the control system's components using the
diagnosis tool.
| Control System Composition |
Features a fail-safe mechanism that prevents dangerous situations from developing in the event of a transmission failure.
The limp home mode engages if the transmission malfunctions.
In this mode, the transmission operates at a minimal functionality
level, making it possible for the vehicle to reach a service center.
Fail-Safe: Allows the vehicle to be driven safely in the event of a malfunction.
Limp Home: Maintains minimal functionality (*) in the event
of a malfunction, making it possible for the vehicle to reach a service
center.
(*) Minimal Functionality: Drive (fixed gear setting), Reverse, and Neutral
TCM is in constant communication with the control system's
components (sensors and solenoids). If an abnormal signal is received
for longer than the predefined duration, TCM recognizes a fault, stores
the fault code in memory, and then sends out a fault signal through the
self-diagnosis terminal. Such fault codes are independently backed up
and will not be cleared even if the ignition switch is turned off, the
battery is disconnected, or the TCM connector is disconnected.
| • |
Disconnecting a sensor or an actuator connector while the
ignition switch is in the "On" position generates a diagnostic trouble
code (DTC) and commits the code to memory. In such event, disconnecting
the battery will not clear the fault diagnosis memory. The diagnosis
tool must be used to clear the fault diagnosis memory. |
| • |
Before removing or installing any part, read the diagnostic
trouble codes and then disconnect the battery negative (-) terminal. |
| • |
Before disconnecting the cable from battery terminal, turn
the ignition switch to OFF. Removal or connection of the battery cable
during engine operation or while the ignition switch is ON could cause
damage to the TCM. |
| • |
When checking the generator for the charging state, do not
disconnect the battery '+' terminal to prevent the ECM from damage due
to the voltage. |
| • |
When charging the battery with the external charger,
disconnect the vehicle side battery terminals to prevent damage to the
TCM. |
|
| Checking Procedure (Self-diagnosis) |
| • |
When battery voltage is excessively low, diagnostic trouble
codes can not be read. Be sure to check the battery for voltage and the
charging system before starting the test. |
| • |
Diagnosis memory is erased if the battery or the TCM
connector is disconnected. Do not disconnect the battery before the
diagnostic trouble codes (DTC) are completely read and recorded.
|
|
| Inspection Procedure (Using the GDS) |
| 1. |
Turn OFF the ignition switch. |
| 2. |
Connect the GDS to the data link connector on the lower crash pad. |
| 3. |
Turn ON the ignition switch. |
| 4. |
Use the GDS to check the diagnostic trouble code. |
| 5. |
Repair the faulty part from the diagnosis chart. |
| 6. |
Erase the diagnostic trouble code. |
| • |
Perform TCM learning after replacing the automatic
transmission to prevent slow automatic transmission response, jerky
acceleration and jerky startup. (Refer to "Automatic transmission
control system (Repair procedures)" in this group) |
| • |
Adding automatic transmission fluid. (Refer to "automatic transmission system" in this group.) |
| • |
After servicing the automatic transmission or TCM, clear the
diagnostic trouble code (DTC) using the GDS tool. Diagnostic trouble
codes (DTC) cannot be cleared by disconnecting the battery. |
|
Adjustment
TCM Learning
When shift shock is occurred or parts related with the transmission are replaced, TCM learning should be performed.
In the following case, TCM learning is required.
...
Hyundai Equus: Description and Operation
Second generation VI (2009–2024) / Hyundai Equus VI 2009-2024 Service Manual / Automatic Transmission System (SBC) / Automatic Transmission Control System / Description and Operation
Repair procedures