System Description

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The 1-2 shift valve performs shifting to 1st gear and other gears. When shifting to 2nd and 4th gears is impossible, or when the ECM directs the transmission to switch to 5th or 6th gear and the engine overruns (clutch slips), this DTC is stored.

DTC No.	Detection Item	DTC Detection Condition	Trouble Area	MIL	Memory	Note
P0781-00	1-2 Shift	All of the following conditions are met (2-trip detection logic): Engine coolant temperature is 40°C (104°F) or higher. The vehicle is driven with the shift lever in D. No malfunctions are detected in shift solenoid valve S1, S2, S3, S4, SR, SL1 and SL2, transmission revolution sensors (NT and SP2), engine coolant temperature sensor, knock control sensor, electronic throttle. Either of the following condition is met: Both of the following conditions are met for 0.4 seconds or more: When the ECM commands the transmission to shift to 2nd gear, the actual gear is shifted to 1st. When the ECM commands the transmission to shift to 4th gear, the actual gear is shifted to 3rd. Both of the following conditions are met for 0.4 seconds or more: When the ECM commands the transmission to shift to 2nd gear, the actual gear is shifted to 1st. When the ECM commands the transmission to shift to 5th gear, the engine overruns (clutch slips).	Shift solenoid valve SLT remains open or closed Transmission valve body assembly is blocked or stuck (1-2 shift valve) Automatic transmission with transfer assembly (clutch, brake, gear, etc.)	Comes on	DTC stored	SAE Code: P0781

HINT:

Gear positions in the event of a shift solenoid valve mechanical problem:

ECM command gearshift	1st	2nd	3rd	4th	5th	6th
Actual gear position under malfunction	1st	1st	3rd	3rd	N*	N*

*: Neutral

Gear position during fail-safe operation:

If any malfunction is detected, the ECM changes into the fail-safe mode to shift into the gear positions as shown in the table below.

Gear position under normal conditions	1st	2nd	3rd	4th	5th	6th
Actual gear position under fail-safe mode	1st*	1st*	3rd	3rd	3rd	3rd

*: Under engine braking, downshifting to 1st or 2nd gear is prohibited.

DTC DETECTION CONDITION PATTERNS:

		Vehicle Condition
		Pattern 1	Pattern 2
Diagnostic Condition	Engine coolant temperature is 40°C (104°F) or higher.	◦	◦
	The vehicle is driven with the shift lever in D.	◦	◦
	No malfunctions are detected in shift solenoid valve S1, S2, S3, S4, SR, SL1 and SL2, transmission revolution sensors (NT and SP2), engine coolant temperature sensor, knock control sensor, electronic throttle.	◦	◦
Malfunction Condition	When the ECM commands the transmission to shift to 2nd gear, the actual gear is shifted to 1st.	◦	◦
	When the ECM commands the transmission to shift to 4th gear, the actual gear is shifted to 3rd.	◦	-
	When the ECM commands the transmission to shift to 5th gear, the engine overruns (clutch slips).	-	◦
Duration		0.4 seconds or more	0.4 seconds or more
Detection Logic		2-trip detection logic	2-trip detection logic

HINT:

This DTC is stored when any of the above detection patterns is met.