Toyota Tacoma (2015-2018) Service Manual: 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. |
INSPECT BATTERY |
(a) Check the battery voltage.
Standard voltage:
11 to 14 V
| NG | .gif) |
CHECK OR REPLACE CHARGING SYSTEM OR BATTERY |
|
.gif)
|
2. |
CHECK HARNESS AND CONNECTOR (+B AND IG TERMINAL) |
(a) Turn the ignition switch off.
|
(b) Disconnect the 4 wheel drive control ECU connector. |
|
(c) Measure the voltage according to the value(s) in the table below.
Standard Voltage:
|
Tester Connection |
Switch Condition |
Specified Condition |
|---|---|---|
|
F13-21 (+B) - Body ground |
Always |
11 to 14 V |
|
F12-4 (IG) - Body ground |
Ignition switch ON |
11 to 14 V |
|
*a |
Front view of wire harness connector (to 4 Wheel Drive Control ECU) |
| NG | |
REPAIR OR REPLACE HARNESS OR CONNECTOR (+B OR IG CIRCUIT) |
|
|
3. |
CHECK HARNESS AND CONNECTOR (GND TERMINAL) |
(a) Turn the ignition switch off.
(b) Disconnect the 4 wheel drive control ECU connector.
|
(c) Measure the resistance according to the value(s) in the table below. Standard Resistance:
|
|
| OK | |
PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE |
| NG | |
REPAIR OR REPLACE HARNESS OR CONNECTOR (GND CIRCUIT) |
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
...
Lock Switch Circuit
WIRING DIAGRAM
PROCEDURE
1.
CHECK REAR DIFFERENTIAL LOCK INDICATOR LIGHT
(a) Turn the ignition switch to ON.
(b) for 4WD:
Finish switching to L4.
(c) Check the ...
Other materials:
Open in Occupant Classification ECU Battery Positive Line (B1794)
DESCRIPTION
DTC B1794 is set when a malfunction is detected in the occupant detection ECU.
DTC No.
DTC Detections Conditions
Trouble Areas
B1794
Occupant detection ECU circuit malfunction
Occupant detection ECU malfuncti ...
Diagnosis System
DIAGNOSIS SYSTEM
1. DESCRIPTION
(a) Smart key system (for start function) data and the Diagnostic Trouble Codes
(DTCs) can be read through the Data Link Connector 3 (DLC3) of the vehicle. When
the system seems to be malfunctioning, use the Techstream to check for malfunctions
and perform rep ...
Data List / Active Test
DATA LIST / ACTIVE TEST
1. DATA LIST
HINT:
Using the Techstream to read the Data List allows the values or states of switches,
sensors, actuators and other items to be read without removing any parts. This non-intrusive
inspection can be very useful because intermittent conditions or signals ...
