Toyota Tacoma (2015-2018) Service Manual: Transfer Shift Motor Control Circuit High (P17AA)

Toyota Tacoma (2015-2018) Service Manual / Vf2cm Transfer / Touch Select 2-4 And High-low System / Transfer Shift Motor Control Circuit High (P17AA)

DESCRIPTION

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

DTC No.	Detection Item	DTC Detection Condition	Trouble Area
P17AA	Transfer Shift Motor Control Circuit High	Diagnosis Condition: Directly after or while the ignition switch is turned to ON (transfer shift motor not operating) Malfunction Status: Short to B+ 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

Refer to DTC P17A9 (See page PROCEDURE )

PROCEDURE

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

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

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

Standard Voltage:

Transfer shift actuator assembly side:

Tester Connection	Switch Condition	Specified Condition
F12-8 (TM1) or F12-7 (TM2) - Body ground	Ignition switch ON	Below 1 V

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

Tester Connection	Switch Condition	Specified Condition
F12-2 (DM1) or F12-6 (DM2) - Body ground	Ignition switch ON	Below 1 V

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 Voltage:

Tester Connection	Switch Condition	Specified Condition
F12-8 (TM1) or T4-2 (TM1) - Body ground	Ignition switch ON	Below 1 V
F12-7 (TM2) or T4-1 (TM2) - Body ground	Ignition switch ON	Below 1 V

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 Voltage:

Tester Connection	Switch Condition	Specified Condition
F12-2 (DM1) or A3-1 (DM1) - Body ground	Ignition switch ON	Below 1 V
F12-6 (DM2) or A3-2 (DM2) - Body ground	Ignition switch ON	Below 1 V

REPLACE DIFFERENTIAL VACUUM ACTUATOR ASSEMBLY

REPAIR OR REPLACE HARNESS OR CONNECTOR

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