Toyota Tundra Service Manual: Four Wheel Drive (4WD) Low Switch Circuit Range / Performance (P2772)

Toyota Tundra Service Manual / Engine, Hybrid System / Wf1am Transfer / Touch Select 2-4 And High-low System / Four Wheel Drive (4WD) Low Switch Circuit Range / Performance (P2772)

DESCRIPTION

When the transfer is switching between 4H and 4L, the H4 and L4 terminals of the transfer indicator switch are in one of the ON/OFF combinations listed in the table below.

Terminal	In 4H	Switching between 4H and 4L	In 4L
H4	OFF (OPEN)	ON (GND)	ON (GND)
L4	OFF (OPEN)	OFF (OPEN)	ON (GND)

This DTC is detected when the 4WD HIGH position and 4WD LOW position judgment signals do not match.

DTC Code

DTC Detection Condition

Diagnosis Condition
Malfunction Status
Malfunction Time
Other

Trouble Area

P2772

Ignition switch is ON and engine is running
H4 terminal signal is OFF (OPEN) and L4 terminal signal is ON (GND)
1 second or more
1 trip detection logic

Wire harness and connector
4 wheel drive control ECU
Transfer indicator switch

WIRING DIAGRAM

PROCEDURE

1.	CHECK HARNESS AND CONNECTOR (4 WHEEL DRIVE CONTROL ECU - TRANSFER INDICATOR SWITCH)

(a) Disconnect the A26 4 wheel drive control ECU connector.

(b) Disconnect the D70 transfer indicator switch connector.

(d) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

Tester Connection	Condition	Specified Condition
A26-13 (L4) - D70-2 (L4)	Always	Below 1 Ω
A26-12 (H4) - D70-1 (H4)	Always	Below 1 Ω
A26-13 (L4), D70-2 (L4) or A24-21 (L4) - Body ground	Always	10 kΩ or higher
A26-12 (H4) or D70-1 (H4) - Body ground	Always	10 kΩ or higher
A26-13 (L4), D70-2 (L4) or A24-21 (L4) - A26-12 (H4) or D70-1 (H4)	Always	10 kΩ or higher

REPAIR OR REPLACE HARNESS OR CONNECTOR

2.	CHECK 4 WHEEL DRIVE CONTROL ECU (ECU OUTPUT VOLTAGE)

(a) Disconnect the A24 ECM connector.

(b) Disconnect the transfer indicator switch connector.

Standard Voltage:

Tester Connection	Switch Condition	Specified Condition
D70-2 (L4) - Body ground	Ignition switch ON	4 to 6 V
D70-1 (H4) - Body ground	Ignition switch ON	4 to 6 V

Text in Illustration

*a	Front view of wire harness connector (to Transfer Indicator Switch)

NOTICE:

Turning the ignition switch on with the ECM connector disconnected causes other DTCs to be stored. Clear the DTCs after performing this inspection.

REPLACE TRANSFER INDICATOR SWITCH

REPLACE 4 WHEEL DRIVE CONTROL ECU

See More:

Toyota Tundra Service Manual > Touch Select 2-4 And High-low System: System Description
SYSTEM DESCRIPTION 1. DESCRIPTION A part-time 2-speed WF1AM transfer uses a touch select 2-4 and high-low system, enabling the driver to switch between 2WD, 4H and 4L modes by turning the transfer position switch. Through these switch signals, the 4 wheel drive control ECU actuates the shift motor i ...

Toyota Tundra Service Manual: Four Wheel Drive (4WD) Low Switch Circuit Range / Performance (P2772)

System Voltage (P0560)

Parts Location

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