Toyota Tacoma (2015-2018) Service Manual: 4WD ECU Malfunction (P163B)

Toyota Tacoma (2015-2018) Service Manual / Differential / Differential System(w/ Rear Differential Lock) / 4WD ECU Malfunction (P163B)

DESCRIPTION

This DTC is output when a malfunction is detected in the 4 wheel drive control ECU internal circuit.

DTC No.	Detection Item	DTC Detection Condition	Trouble Area
P163B	4WD ECU Malfunction	Diagnosis Condition: Directly after ignition switch is turned to ON, or when switching operations are performed with ignition switch turned to ON Malfunction Status: 4 wheel drive control ECU internal circuit malfunction Malfunction Time: 0.5 seconds or more (directly after the ignition switch is turned to ON, 0.05 seconds or more) Other: 1 trip detection logic	Wire harness and connector Differential lock coil 4 wheel drive control ECU

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

4WD specification:

If P163B is detected, troubleshoot the TOUCH SELECT 2-4 AND HIGH-LOW system first.

PROCEDURE

1.	CHECK HARNESS AND CONNECTOR (4 WHEEL DRIVE CONTROL ECU - DIFFERENTIAL LOCK COIL)

(a) Turn the ignition switch off.

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

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
F12-1 (SL+) - D28-2 (SL+)	Always	Below 1 Ω
F12-5 (SL-) - D28-1 (SL-)	Always	Below 1 Ω
F12-1 (SL+) or D28-2 (SL+) - Body ground	Always	10 kΩ or higher
F12-5 (SL-) or D28-1 (SL-) - Body ground	Always	10 kΩ or higher

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

Standard Voltage:

Tester Connection	Switch Condition	Specified Condition
F12-1 (SL+) or D28-2 (SL+) - Body ground	Ignition switch ON	Below 1 V
F12-5 (SL-) or D28-1 (SL-) - Body ground	Ignition switch ON	Below 1 V

REPAIR OR REPLACE HARNESS AND CONNECTOR

2.	INSPECT DIFFERENTIAL LOCK COIL

(a) Turn the ignition switch off.

(b) Disconnect the D28 differential lock coil connector.

Standard Resistance:

Tester Connection	Condition	Specified Condition
1 (SL-) - 2 (SL+)	Always	2.65 to 2.95 Ω
1 (SL-) or 2 (SL+) - Body ground	Always	10 kΩ or higher

Text in Illustration

*a	Component without harness connected (Differential Lock Coil)

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

Standard Voltage:

Tester Connection	Switch Condition	Specified Condition
1 (SL-) or 2 (SL+) - Body ground	Ignition switch ON	Below 1 V

REPLACE 4 WHEEL DRIVE CONTROL ECU

REPLACE DIFFERENTIAL LOCK COIL

Rear Differential Lock Position SW Stuck ON (P17BC)

DESCRIPTION This DTC is output when an ON malfunction of the differential lock indicator switch is detected. DTC No. Detection Item DTC Detection Condition ...

ECU Power Source Circuit

WIRING DIAGRAM CAUTION / NOTICE / HINT NOTICE: Inspect the fuses for circuits related to this system before performing the following inspection procedure. PROCEDURE 1. ...

Other materials:

Installation
INSTALLATION CAUTION / NOTICE / HINT HINT: Use the same procedure for both the RH and LH sides. The procedure described below is for the LH side. PROCEDURE 1. INSTALL REAR AIRBAG SENSOR (a) Check that the ignition switch is off. (b) Check that the battery negative (-) termin ...

Terminals Of Ecm
TERMINALS OF ECM HINT: The standard normal voltage between each pair of ECM terminals is shown in the table below. The appropriate conditions for checking each pair of terminals are also indicated. The result of checks should be compared with the standard normal voltage for that pair of te ...

Diagnostic Trouble Code Chart
DIAGNOSTIC TROUBLE CODE CHART LANE DEPARTURE ALERT SYSTEM DTC No. Detection Item Link C1A47 Steering Angle Sensor C1AA0 Front Camera Module Circuit C1AA1 F ...