Toyota Tacoma Quiz
Differential

4WD ECU Malfunction (P163B)

In this manual: Differential
Introduction — 15Maintenance — 8Audio / Video — 94Garage Door Opener — 7Navigation / Multi Info Display — 84Park Assist / Monitoring — 86Brake — 50Brake Control / Dynamic Control Systems — 165Parking Brake — 52gr-fks Charging — 252gr-fks Cooling — 212gr-fks Emission Control — 132gr-fks Engine Control — 322gr-fks Engine Mechanical — 332gr-fks Exhaust — 92gr-fks Fuel — 422gr-fks Ignition — 62gr-fks Intake — 72gr-fks Lubrication — 152gr-fks Starting — 38Ac60e Automatic Transmission / Transaxle — 146Axle — 19Clutch — 20Cruise Control — 168Differential — 50Drive Shaft — 6Propeller Shaft — 23Rc62f Manual Transmission / Transaxle — 34Suspension — 22Tire And Wheel — 39Vf2cm Transfer — 44Can Communication — 45Multiplex Communication — 20Power Distribution — 5Power Steering — 29Steering Column — 29Air Conditioning — 108Door Lock — 88Engine Hood / Door — 16Engine Immobiliser — 47Exterior — 55Horn — 5Interior — 18Interior Panel — 8Lighting — 93Meter / Gauge / Display — 31Mirror — 22Other System — 24Pre-collision — 40Seat — 52Seat Belt — 40Sliding Roof — 26Supplemental Restraint Systems — 139Theft Deterrent — 20Window / Glass — 53Wiper / Washer — 24
~2min read
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 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.

(c) Disconnect the D28 differential lock coil 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
NG

REPAIR OR REPLACE HARNESS AND CONNECTOR
OK

  1. INSPECT DIFFERENTIAL LOCK COIL

(a) Turn the ignition switch off.

(b) Disconnect the D28 differential lock coil connector.

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

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
OK

REPLACE 4 WHEEL DRIVE CONTROL ECU
NG

REPLACE DIFFERENTIAL LOCK COIL

Test yourself

A quick Toyota Tacoma quiz: every answer comes with an explanation and a link to the manual page.