DTC Advanced Diagnostics: P1A4E

DTC P1A4E : TCM Internal Control Module Move to Different Direction

General Description

When the transmission control module (TCM) shifting control malfunctions, it may cause unintended vehicle action contrary to the selected shift position/mode. Unintended vehicle action contrary to the selected shift position/mode may occur by a cause of abnormal engagement combinations of the clutch and the brake or abnormal switching of the parking actuator valve and the two-way clutch. The TCM monitors the conditions of the clutch, the brake, the parking actuator valve, and the two-way clutch to secure safety before the vehicle leads to unintended vehicle action to the selected shift position/mode. The TCM presumes that there is abnormal engagement of the clutch and the brake to the selected shift position/mode or abnormal switching of the parking actuator valve and the two-way clutch to the selected shift position/mode from the values of the transmission fluid pressure sensor, the parking actuator valve stroke sensor, and the two-way clutch actuator valve stroke sensor. If the TCM determines a shifting control malfunction, a DTC is stored.

Monitor Execution, Sequence, Duration, DTC Type

Execution	Continuous
Sequence	None
Duration	0.4 second or less
DTC Type	Two drive cycles, MIL on, shift position indicator blinks

Enable Conditions

Condition		Minimum	Maximum
Vehicle speed [Vehicle Speed]		-	31 mph (50 km/h)

[ ]: HDS Parameter

Malfunction Threshold

From the values of the transmission fluid pressure sensor, the parking actuator valve stroke sensor, and the two-way clutch actuator valve stroke sensor, the TCM determines as abnormal engagement of the clutch and the brake to the selected shift position/mode or abnormal switching of the parking actuator valve and the two-way clutch to the selected shift position/mode.

The following symptoms appear when abnormal engagement of the clutch and the brake to the selected shift position/mode or abnormal switching of the parking actuator valve and the two-way clutch to the selected shift position/mode are occurred:

Shift position/mode	Symptom
R	Forward driving
N	Forward driving/Reverse driving
D, S	Reverse driving
P	Forward driving/Reverse driving

Possible Cause

NOTE: The causes shown may not be a complete list of all potential problems, and it is possible that there may be other causes.

TCM internal circuit failure

Diagnosis Details

Conditions for setting the DTC

When a malfunction is detected during the first drive cycle, a Pending DTC is stored in the TCM memory. If the malfunction returns in the next (second) drive cycle, the MIL comes on, the shift position indicator blinks, and a Confirmed DTC and the freeze data are stored.

Conditions for clearing the DTC

The shift position indicator comes off by turning the vehicle to the OFF (LOCK) mode. The MIL is cleared if the malfunction does not return in three consecutive trips in which the diagnostic runs. The MIL, the Pending DTC, the Confirmed DTC, and the freeze data can be cleared with the scan tool clear command.