Hyundai Palisade: Automatic Transaxle System (A8LF1) / Troubleshooting

Hyundai Palisade (LX2) 2020-2024 Service Manual / Automatic Transaxle System (A8LF1) / Troubleshooting

Troubleshooting

Limp Home Mode

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Features a fail-safe function that prevents dangerous situations in the event of a transaxle failure. The vehicle will be driven in limp home mode if the transaxle malfunctions. In this mode, the transaxle operates at a minimal functionality level (fixed shifting, limited shifting, reverse, neutral), making it possible for the vehicle to reach a service center.

•	Limp Home Mode : Limited shifting

•	Mechanical limp home mode : Fixed shifting (failure of mechanical parts, solenoid valves, TCM, CAN communication)

Troubleshooting

symptoms		Suspected areas	Remedy
Delayed shifting / shift shock while driving	1st → 2nd or 2nd → 1st	1. 28, OD&LR solenoid valve fault (If shifting 4th to 5th operates as normal, replace 28 solenoid valve) 2. 28, LR brake fault	1. Replace the faulty solenoid valve 2. Check for the clutch/brake abnormality - Disc damage - Piston D-ring damage - Clutch sealing damage ※ Replace the transaxle assembly when the clutch/brake damaged ※When a shift shock occurs, check the shift position in manual mode and reproduce the symptoms.
	2nd → 3rd or 3rd → 2nd	1. 37R, 28 solenoid valve fault (If shifting 1st to 2nd operates as normal, replace 37R solenoid valve) 2. 37R, 28 clutch fault
	3rd → 4th or 4th → 3rd	1. 46, 37R solenoid valve fault (If shifting 2nd to 3rd operates as normal, replace 46 solenoid valve) 2. 46, 37R clutch fault
	4th → 5th or 5th → 4th	1. OD&LR, 46 solenoid valve fault (If shifting 3rd to 4th operates as normal, replace OD solenoid valve) 2. OD, 46 clutch fault
	5th → 6th or 6th → 5th	1. 46, OD&LR solenoid valve fault (If shifting 4th to 5th operates as normal, replace 46 solenoid valve) 2. 46, OD clutch fault
	6th → 7th or 7th → 6th	1. 37R, 46 solenoid valve fault (If shifting 4th to 5th operates as normal, replace 37R solenoid valve) 2. 37R, 46 clutch fault
	7th → 8th or 8th → 7th	1. 28, 37R solenoid valve fault (If shifting 3rd to 4th operates as normal, replace 28 solenoid valve) 2. 28, 37R clutch fault
Shifting shock while stopped	N → D / N → R	1. D position : UD solenoid valve fault 2. R position : 37R solenoid valve fault 3. UD/37R clutch fault	1. Replace UD solenoid valve 2. Replace 37R solenoid valve 3. Inspect UD/37R clutch
Thumping noise	P → D	Sound occurs when the parking sprague is released	Normal
Vibrating while stopped (in the N position)	N	UD solenoid valve fault	Replace the UD solenoid valve
Delay/jerk when the damper is engaged		1. ECM / TCM mapping 2. The damper clutch solenoid valve fault 3. Torque converter oil flow path pressure leakage 3. The Oil Level Low	Check the current state using the dirogger 1. The ECM / TCM update 2. Replace the valve body assembly 3. Replace the torque converter and the inspect oil level
Blinking the cluster gear position lamp		Oil pressure characteristics values not entered	Enter the oil pressure characteristics values
Mechanical limp home mode (locked into 5th)		The solenoid valve fault	Replace the faulty solenoid valve
		TCM fault	Replace the TCM
		CAN communication fault	Inspect the CAN communication line
		The position switch fault	Replace the position switch
		The position switch fault	Inspect the position switch connector connection
Limp home mode (locked into 5th, 2nd - 5th manual shift enabled)		Input & output speed sensor fault	Replace the speed sensor
		The connector connection fault	Inspect the main connector connection
		The connector connection fault	Replace the main harness
Manual shift disabled		TCM fault	Replace the TCM
		The Connector connection fault	Check shift lever connector connection
		The manual mode switch fault	Replace the shift lever

▶ Self-diagnosis

Transaxle Control Module (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.

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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 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 Transaxle Control Module (TCM).

•	When checking the generator for the charging state, do not disconnect the battery '+' terminal to prevent the Engine Control Module (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.

•	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.

▶ Inspection Procedure (Using the diagnostic tool)

1.	Turn OFF the ignition switch.

2.	Connect the diagnostic tool to the data link connector on the lower crash pad.

3.	Turn ON the ignition switch.

4.	Use the diagnostic tool to check the diagnostic trouble code.

5.	Repair the faulty part from the diagnosis chart.

6.	Erase the diagnostic trouble code.

7.	Disconnect the diagnostic tool.

Special service tools

Special Service Tools Tool Name / Number Illustration Description 09200-3N000 Engine support fixture (Beam) Removal and installation of the transaxle...

Automatic Transaxle System

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