Toyota Tacoma (2015-2018) Service Manual: Transfer Shift Motor Control Circuit Low (P17A9)

Toyota Tacoma (2015-2018) Service Manual / Vf2cm Transfer / Touch Select 2-4 And High-low System / Transfer Shift Motor Control Circuit Low (P17A9)

DESCRIPTION

This DTC is output when a short to ground in the transfer shift motor and A.D.D. shift motor drive circuit is detected.

DTC No.	Detection Item	DTC Detection Condition	Trouble Area
P17A9	Transfer Shift Motor Control Circuit Low	Diagnosis Condition: Directly after the ignition switch is turned to ON, or while the ignition switch is turned to ON (transfer shift motor not operating) Malfunction Status: Short to ground in the transfer shift motor and A.D.D. shift motor drive circuits Malfunction Time: 0.5 seconds or more (after the ignition switch is turned to ON, 0.05 seconds or more) Other: 1 trip detection logic	Wire harness and connector 4 wheel drive control ECU Transfer shift actuator assembly A.D.D. actuator (differential vacuum actuator assembly)

WIRING DIAGRAM

PROCEDURE

1.	CHECK ACTUATOR ASSEMBLY (TRANSFER SHIFT MOTOR OR A.D.D. SHIFT MOTOR)

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

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

Standard Resistance:

Transfer shift actuator assembly side:

Tester Connection	Condition	Specified Condition
F12-8 (TM1) or F12-7 (TM2) - Body ground	Always	10 kΩ or higher

A.D.D. actuator (differential vacuum actuator assembly) side:

Tester Connection	Condition	Specified Condition
F12-2 (DM1) or F12-6 (DM2) - Body ground	Always	10 kΩ or higher

Text in Illustration

*a	Front view of wire harness connector (to 4 Wheel Drive Control ECU)

Result

Result	Proceed to
OK	A
NG (transfer shift actuator assembly side)	B
NG (A.D.D. actuator (differential vacuum actuator assembly) side)	C

REPLACE 4 WHEEL DRIVE CONTROL ECU

GO TO STEP 3

2.	CHECK HARNESS AND CONNECTOR (4 WHEEL DRIVE CONTROL ECU AND TRANSFER SHIFT ACTUATOR ASSEMBLY - BODY GROUND)

(a) Disconnect the F12 4 wheel drive control ECU connector.

(b) Disconnect the T4 transfer shift actuator assembly connector.

Standard Resistance:

Tester Connection	Condition	Specified Condition
F12-8 (TM1) or T4-2 (TM1) - Body ground	Always	10 kΩ or higher
F12-7 (TM2) or T4-1 (TM2) - Body ground	Always	10 kΩ or higher

REPLACE TRANSFER SHIFT ACTUATOR ASSEMBLY

REPAIR OR REPLACE HARNESS OR CONNECTOR

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

(a) Disconnect the F12 4 wheel drive control ECU connector.

(b) Disconnect the A3 A.D.D. actuator (differential vacuum actuator assembly) connector.

Standard Resistance:

Tester Connection	Condition	Specified Condition
F12-2 (DM1) or A3-1 (DM1) - Body ground	Always	10 kΩ or higher
F12-6 (DM2) or A3-2 (DM2) - Body ground	Always	10 kΩ or higher

REPLACE DIFFERENTIAL VACUUM ACTUATOR ASSEMBLY

REPAIR OR REPLACE HARNESS OR CONNECTOR

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