Toyota Tundra Service Manual: Automatic Disconnecting Differential Motor Limit Switch Circuit (P17A4)

Toyota Tundra Service Manual / Engine, Hybrid System / Wf1am Transfer / Touch Select 2-4 And High-low System / Automatic Disconnecting Differential Motor Limit Switch Circuit (P17A4)

DESCRIPTION

When the A.D.D. actuator is switching between 2WD and 4WD, the DL1 and DL2 terminals of the limit switch are in one of the ON/OFF combinations listed in the table below.

Terminal	In 2WD	Switching between 2WD and 4WD	In 4WD
DL1	OFF (OPEN)	ON (GND)	ON (GND)
DL2	ON (GND)	ON (GND)	OFF (OPEN)

This DTC is detected when the limit switch ON/OFF combination (2 lines) is abnormal.

DTC Code

DTC Detection Condition

Diagnosis Condition
Malfunction Status
Malfunction Time
Other

Trouble Area

P17A4

Ignition switch is ON and engine is running
Limit switch DL1 terminal is OFF (OPEN) and the DL2 terminal is OFF (OPEN)
1 second or more
1 trip detection logic

Wire harness and connector
4 wheel drive control ECU
A.D.D. actuator (differential vacuum actuator assembly)

WIRING DIAGRAM

PROCEDURE

1.	CHECK HARNESS AND CONNECTOR (4 WHEEL DRIVE CONTROL ECU - DIFFERENTIAL VACUUM ACTUATOR ASSEMBLY)

(a) Disconnect the A25 4 wheel drive control ECU connector.

(b) Disconnect the G1 A.D.D. actuator (differential vacuum actuator assembly) connector.

Standard Resistance:

Tester Connection	Condition	Specified Condition
A25-7 (DL1) - G1-6 (DL1)	Always	Below 1 Ω
A25-20 (DL2) - G1-5 (DL2)	Always	Below 1 Ω
G1-4 (GND) - Body ground	Always	Below 1 Ω
A25-7 (DL1) or G1-6 (DL1) - Body ground	Always	10 kΩ or higher
A25-20 (DL2) or G1-5 (DL2) - Body ground	Always	10 kΩ or higher

REPAIR OR REPLACE HARNESS OR CONNECTOR

2.	INSPECT DIFFERENTIAL VACUUM ACTUATOR ASSEMBLY (LIMIT SWITCH)

(a) Disconnect the G1 A.D.D. actuator (differential vacuum actuator assembly) connector.

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
6 (DL1) - Body ground	Always	10 kΩ or higher
5 (DL2) - Body ground	Always	10 kΩ or higher

Text in Illustration

*a	Component without harness connected (A.D.D. Actuator [Differential Vacuum Actuator Assembly])

REPLACE DIFFERENTIAL VACUUM ACTUATOR ASSEMBLY

REPLACE 4 WHEEL DRIVE CONTROL ECU

Automatic Disconnecting Differential Motor Control Circuit High (P17A2)

Transfer Synchronization Actuator Circuit Open (P17A5,P17A6)

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