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 AND IG CIRCUIT) |
|
|
3. |
CHECK HARNESS AND CONNECTOR (GND TERMINAL) |
(a) Turn the ignition switch off.
|
(b) 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 Control Switch Circuit
WIRING DIAGRAM
PROCEDURE
1.
CONFIRM PROBLEM SYMPTOM
(a) Confirm the problem symptoms.
Result
Result
Proceed to
The 4WD ind ...
Other materials:
Low Power Supply Voltage Malfunction (C1241)
DESCRIPTION
If a malfunction is detected in the power supply circuit, the skid control ECU
(brake actuator assembly) stores this DTC and the fail-safe function prohibits ABS
operation.
This DTC is stored when the +BS terminal voltage deviates from the DTC detection
condition due to a malfunc ...
Diagnostic Trouble Code Chart
DIAGNOSTIC TROUBLE CODE CHART
Smart Key System
DTC Code
Detection Item
See page
B27A1
Open in Driver Side Electrical Antenna Circuit
B27A5
Open in Front Floor Electrical Key Oscillator Circuit
...
Terminals Of Ecu
TERMINALS OF ECU
1. CHECK CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)
(a) Disconnect the C27 and C29 certification ECU (smart key ECU assembly) connectors.
(b) Measure the voltage and resistance according to the value(s) in the table
below.
HINT:
Measure the values on the wire harness side w ...
