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Automatic Transaxle DTC Diagnosis - A4CF2: Overview Kia Forte I

Automatic Trans ~2468 words

General Description

The TCU checks ROM ID all the time, in order to maintain optimal conditions.

DTC Description

The TCU set this code When the ROM ID is changed by external force or input non-available data

The Transaxle Range Switch sends the shift lever position information to the TCM (PCM) using a 12V (battery voltage) signal. When the shift lever is in the D (Drive) position the output signal of Transaxle Range Switch is 12V, and in all other positions the voltage is 0V. The TCM (PCM) judges the shift lever position by reading all signals, for the Transaxle Range Switch, simultaneously.

The TCM (PCM) sets this code when the Transaxle Range Switch has no output signal for more than 30 seconds.

The Transaxle Range Switch sends the shift lever position information to the TCM using a 12V (battery voltage) signal. When the shift lever is in the D (Drive) position the output signal of Transaxle Range Switch is 12V, and in all other positions the voltage is 0V. The TCM judges the shift lever position by simultaneously reading all signals for the Transaxle Range Switch.

The TCM sets this code when the Transaxle Range Switch outputs multiple signals for more than 10 seconds.

The automatic Oil temperature sensor is installed in the Valve Body. This sensor uses a thermistor whose resistance changes according to the temperature changes.

The TCM supplies a 5V reference voltage to the sensor, and the output voltage of the sensor changes when the ATF temperature varies.

The Oil (ATF) temperature provides very important data for the TCM's control of the Torque Converter Clutch, and is also used for many other purposes.

This DTC code is set when the ATF temperature output voltage is lower than a value generated by thermistor resistance, in a normal operating range, for approximately 1 second or longer. The TCM regards the ATF temperature as fixed at a value of 80°C (176°F).

The automatic Oil temperature sensor is installed in the Valve Body. This sensor uses a thermistor whose resistance changes according to the temperature changes.

The TCM supplies a 5V reference voltage to the sensor, and the output voltage of the sensor changes when the ATF temperature varies.

The Oil (ATF) temperature provides very important data for the TCM's control of the Torque Converter Clutch, and is also used for many other purposes.

This DTC code is set when the ATF temperature output voltage is lower than a value generated by thermistor resistance, in a normal operating range, for approximately 1 second or longer. The TCM regards the ATF temperature as fixed at a value of 80°C (176°F).

The automatic Oil temperature sensor is installed in the Valve Body. This sensor uses a thermistor whose resistance changes according to the temperature changes.

The TCM supplies a 5V reference voltage to the sensor, and the output voltage of the sensor changes when the ATF temperature varies.

The Oil (ATF) temperature provides very important data for the TCM's control of the Torque Converter Clutch, and is also used for many other purposes.

This DTC code is set when the ATF temperature output voltage is higher than a value generated by thermistor resistance, in a normal operating range, for an extended period of time. The TCM regards the ATF temperature as fixed at a value of 80 °C (176°F).

The input (turbine) speed sensor outputs pulse-signals according to the revolutions of the input shaft of the transmission. The PCM/TCM determines the input shaft speed by counting the frequency of the pulses. This value is mainly used to control the optimum fluid pressure during shifting.

The PCM/TCM sets this code if an output pulse-signal is not detected, from the input speed sensor, when the vehicle is running faster than 30 km/h. The Fail-Safe function will be set by the PCM/TCM if this code is detected.

The Output Speed Sensor outputs pulse-signals according to the revolutions of the output shaft of the transmission. The Output Speed Sensor is installed in front of the Transfer Drive Gear to determine the Transfer Drive Gear RPM by counting the frequency of the pulses. This value, together with the throttle position data, is mainly used to decide the optimum gear position.

The PCM (TCM) sets this code if the calculated value of the signals is noticeably different from the value calculated, using the Vehicle Speed Sensor output, when the vehicle is running faster than 18MPH (30km/h). The PCM (TCM) will initiate the fail safe function if this code is detected.

The Output Speed Sensor outputs pulse-signals according to the revolutions of the output shaft of the transmission. The Output Speed Sensor is installed in front of the Transfer Drive Gear to determine the Transfer Drive Gear RPM by counting the frequency of the pulses. This value, together with the throttle position data, is mainly used to decide the optimum gear position.

The PCM (TCM) sets this code if the calculated value of the pulse-signal is noticeably different from the value calculated, using the Vehicle Speed Sensor output, when the vehicle is running faster than 30 km/h (18MPH). The PCM (TCM) will initiate the fail safe function if this code is detected.

The value of the input shaft speed should be equal to the value of the output shaft speed, when multiplied by the 1st gear ratio, while the transaxle is engaged in the 1st gear. For example, if the output speed is 1000 RPM and the 1st gear ratio is 2.842, then the input speed is 2842 RPM.

This code is set if the value of input shaft speed is not equal to the value of the output shaft, when multiplied by the 1st gear ratio, while the transaxle is engaged in 1st gear. This malfunction is mainly caused by mechanical troubles such as control valve sticking or solenoid valve malfunctioning rather than an electrical issue.

The value of the input shaft speed should be equal to the value of the output shaft speed, when multiplied by the 2nd gear ratio, while the transaxle is engaged in the 2nd gear. For example, if the output speed is 1000 RPM and the 2nd gear ratio is 1.529, then the input speed is 1529 RPM.

This code is set if the value of input shaft speed is not equal to the value of the output shaft, when multiplied by the 2nd gear ratio, while the transaxle is engaged in 2nd gear. This malfunction is mainly caused by mechanical troubles such as control valve sticking or solenoid valve malfunctioning rather than an electrical issue.

The value of the input shaft speed should be equal to the value of the output shaft speed, when multiplied by the 3rd gear ratio, while the transaxle is engaged in the 3rd gear. For example, if the output speed is 1,000 RPM and the 3rd gear ratio is 1.000, then the input speed is 1000 RPM.

This code is set if the value of input shaft speed is not equal to the value of the output shaft, when multiplied by the 3rd gear ratio, while the transaxle is engaged in 3rd gear. This malfunction is mainly caused by mechanical troubles such as control valve sticking or solenoid valve malfunctioning rather than an electrical issue.

The value of the input shaft speed should be equal to the value of the output shaft speed, when multiplied by the 4th gear ratio, while the transaxle is engaged in the 4th gear. For example, if the output speed is 1,000 RPM and the 4th gear ratio is 0.712, then the input speed is 712 RPM.

This code is set if the value of input shaft speed is not equal to the value of the output shaft, when multiplied by the 4th gear ratio, while the transaxle is engaged in 4th gear. This malfunction is mainly caused by mechanical troubles such as control valve sticking or solenoid valve malfunctioning rather than an electrical issue.

The PCM/TCM controls the locking and unlocking of the Torque Converter Clutch (or Damper Clutch), to the input shaft of the transmission, by applying hydraulic pressure. The main purpose of T/C clutch control is to save fuel by decreasing the hydraulic load inside the T/C. The PCM/PCM/TCM outputs duty pulses to control the Damper Clutch Control Solenoid Valve (TCCSV) and hydraulic pressure is applied to the DC according to the TCC duty ratio value. When the duty ratio is high, high pressure is applied and the Damper Clutch is locked. The normal operating range of the Damper Clutch Control duty ratio value is from 30%(unlocked) to 85%(locked).

The PCM/TCM increases the duty ratio to engage the Damper Clutch by monitoring slip RPM (difference value between engine speed and turbine speed). To decrease the slip of the Damper Clutch, the PCM/TCM increases the duty ratio by applying more hydraulic pressure. When slip RPM does not drop under some value with 100% duty ratio, the PCM/TCM determines that the Torque Converter Clutch is stuck OFF and sets this code.

The PCM/TCM controls the locking and unlocking of the Torque Converter Clutch (or Damper Clutch), to the input shaft of the transmission, by applying hydraulic pressure. The main purpose of T/C clutch control is to save fuel by decreasing the hydraulic load inside the T/C. The PCM/PCM/TCM outputs duty pulses to control the Damper Clutch Control Solenoid Valve (TCCSV) and hydraulic pressure is applied to the DC according to the TCC duty ratio value. When the duty ratio is high, high pressure is applied and the Damper Clutch is locked. The normal operating range of the Damper Clutch Control duty ratio value is from 30%(unlocked) to 85%(locked).

The PCM/TCM checks the Damper Clutch Control Signal by monitoring the feedback signal from the solenoid valve drive circuit. If an unexpected signal is monitored (for example, high voltage is detected when low voltage is expected, or low voltage is detected when high voltage is expected) the PCM/TCM judges that TCCSV circuit is malfunctioning and sets this code.

The Variable Forced Solenoid (Linear Solenoid) controls the amount of oil flow, which is determined by a current signal for maintaining constant line pressure. The amount of oil flow is decided by how widely the spool valve opens the oil passage.

The TCM checks the VFS Control Signal by monitoring the feedback signal from the solenoid valve drive circuit. If an unexpected signal is monitored (for example, high voltage is detected when low voltage is expected, or low voltage is detected when high voltage is expected), the TCM judges that the Low and Reverse control solenoid circuit is malfunctioning and sets this code.

The Automatic Transmission changes the gear position of the transmission utilizing a combination of Clutches and Brakes, which are controlled by solenoid valves. This Automatic Transmission consists of: a LR (Low and Reverse Brake), 2-4 (2-4 Brake), UD (Under Drive Clutch), OD (Over Drive Clutch), and a REV (Reverse Clutch).

The PCM/TCM checks the Low and Reverse Control Signal by monitoring the feedback signal from the solenoid valve drive circuit. If an unexpected signal is monitored (for example, high voltage is detected when low voltage is expected, or low voltage is detected when high voltage is expected), the PCM/TCM judges that the Low and Reverse control solenoid circuit is malfunctioning and sets this code.

The Automatic Transmission changes the gear position of the transmission utilizing a combination of Clutches and Brakes, which are controlled by solenoid valves. This Automatic Transmission consists of: a LR (Low and Reverse Brake), 2-4 (2-4 Brake), UD (Under Drive Clutch), OD (Over Drive Clutch), and a REV (Reverse Clutch).

The PCM/TCM checks the Over Drive Clutch Control/Low & Reverse Brake Signal by monitoring the feedback signal from the solenoid valve drive circuit. If an unexpected signal is monitored (for example, high voltage is detected when low voltage is expected, or low voltage is detected when high voltage is expected), the PCM/TCM judges that Under Drive Clutch control solenoid circuit is malfunctioning and sets this code.

The Automatic Transmission changes the gear position of the transmission utilizing a combination of Clutches and Brakes, which are controlled by solenoid valves. This Automatic Transmission consists of: a LR (Low and Reverse Brake), 2-4 (2-4 Brake), UD (Under Drive Clutch), OD (Over Drive Clutch), and a REV (Reverse Clutch).

The PCM/TCM checks the 2-4 SOLENOID VALVE Control Signal by monitoring the feedback signal from the solenoid valve drive circuit. If an unexpected signal is monitored, (For example, high voltage is detected when low voltage is expected or low voltage is detected when high voltage is expected) the PCM/TCM judges that 2nd Brake drive control solenoid circuit is malfunctioning and sets this code.

The Automatic Transmission changes the gear position of the transmission utilizing a combination of Clutches and Brakes, which are controlled by solenoid valves. This Automatic Transmission consists of: a LR (Low and Reverse Brake), 2-4 (2-4 Brake), UD (Under Drive Clutch), OD (Over Drive Clutch), and a REV (Reverse Clutch).

The PCM/TCM checks the Under Drive Clutch Control Signal by monitoring the feedback signal from the solenoid valve drive circuit. If an unexpected signal is monitored (for example, high voltage is detected when low voltage is expected or low voltage is detected when high voltage is expected), the PCM/TCM judges that the OVER DRIVE CLUTCH drive control solenoid circuit is malfunctioning and sets this code.

The PCM (TCM) monitors supplied voltage to "SOLENOID VALVE".

The gear position is fixed at 3rd gear when input value is higher or lower than specification.

The PCM (TCM) set this code If an input voltage is higher or lower than specification.

The TCM can either receive data from the Engine Control Module or ABS Control Module, or it can send data to the ECM and ABS Control Module by using CAN communication. The CAN communication is one of the vehicle communications methods, which is now widely used to transfer the vehicle data.

The TCM reads data on the CAN-BUS line and checks whether the data is equal to the data which the TCM sent before. If the data is not the same, the TCM decides that either the CAN-BUS line or TCM are malfunctioning and sets this code.

The TCM can either receive data from the Engine Control Module or ABS Control Module, or it can send data to the ECM and ABS Control Module by using CAN communication. The CAN communication is one of the vehicle communications methods, which is now widely used to transfer the vehicle data.

The TCM reads data on the CAN-BUS line and checks whether the data is equal to the data which the TCM sent before. If the data is not the same, the TCM decides that either the CAN-BUS line or TCM are malfunctioning and sets this code.