Toyota 4Runner: Short to GND in Motor LH Circuit (21,23)

Toyota 4Runner Service Manual / Vehicle Exterior / Exterior Panels / Trim / Automatic Running Board System / Short to GND in Motor LH Circuit (21,23)

DESCRIPTION

When there is a short to GND in the side auto step motor circuit, the side auto step controller ECU assembly does not operate the automatic running board.

DTC No.	Detection Condition	Trouble Area
21	Short to GND in the circuit on the stowing or deploying side of the side auto step motor LH.	Side auto step motor assembly Side auto step controller ECU assembly Wire harness or connector
23	Short to GND in the circuit on the stowing or deploying side of the side auto step motor RH.

WIRING DIAGRAM

PROCEDURE

1.	INSPECT SIDE AUTO STEP MOTOR ASSEMBLY

(a) Disconnect the O25*1 or N23*2 side auto step motor assembly connector.

*1: for LH
*2: for RH

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

Standard Resistance:

for LH

Tester Connection	Condition	Specified Condition
O25-4 (STW1) - Body ground	Always	10 kΩ or higher
O25-4 (STW1) - O25-1 (-1)	Always	10 kΩ or higher
O25-5 (DPL1) - Body ground	Always	10 kΩ or higher
O25-5 (DPL1) - O25-1 (-1)	Always	10 kΩ or higher

for RH

Tester Connection	Condition	Specified Condition
N23-4 (STW2) - Body ground	Always	10 kΩ or higher
N23-4 (STW2) - N23-1 (-2)	Always	10 kΩ or higher
N23-5 (DPL2) - Body ground	Always	10 kΩ or higher
N23-5 (DPL2) - N23-1 (-2)	Always	10 kΩ or higher

Text in Illustration

Component without harness connected

(Side Auto Step Motor Assembly)

for LH

for RH

REPLACE SIDE AUTO STEP MOTOR ASSEMBLY

2.	CHECK HARNESS AND CONNECTOR (SIDE AUTO STEP MOTOR - SIDE AUTO STEP CONTROLLER ECU)

(a) Disconnect the A42 side auto step controller ECU assembly connector.

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

Standard Resistance:

for LH

Tester Connection	Condition	Specified Condition
A42-3 (STW1) - Body ground	Always	10 kΩ or higher
A42-4 (DPL1) - Body ground	Always	10 kΩ or higher

for RH

Tester Connection	Condition	Specified Condition
A42-2 (STW2) - Body ground	Always	10 kΩ or higher
A42-1 (DPL1) - Body ground	Always	10 kΩ or higher

REPLACE SIDE AUTO STEP CONTROLLER ECU ASSEMBLY

REPAIR OR REPLACE HARNESS OR CONNECTOR

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