Toyota Tacoma (2015-2018) Service Manual: Back-up Power Source Circuit
DESCRIPTION
The back-up power source circuit for the air conditioning amplifier assembly is shown below. Power is supplied even when the ignition switch is off. The power is used for diagnostic trouble code memory, etc.
WIRING DIAGRAM
CAUTION / NOTICE / HINT
NOTICE:
Inspect the fuses for circuits related to this system before performing the following inspection procedure.
PROCEDURE
|
1. |
CHECK HARNESS AND CONNECTOR (AIR CONDITIONING AMPLIFIER ASSEMBLY - BATTERY) |
(a) Disconnect the A36 air conditioning amplifier assembly connector.
(b) Measure the voltage according to the value(s) in the table below.
Standard Voltage:
|
Tester Connection |
Condition |
Specified Condition |
|---|---|---|
|
A36-17 (B) - Body ground |
Always |
11 to 14 V |
| NG | .gif) |
REPAIR OR REPLACE HARNESS OR CONNECTOR |
|
.gif)
|
2. |
CHECK HARNESS AND CONNECTOR (AIR CONDITIONING AMPLIFIER ASSEMBLY - BODY GROUND) |
(a) Disconnect the A36 air conditioning amplifier assembly connector.
(b) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
|
Tester Connection |
Condition |
Specified Condition |
|---|---|---|
|
A36-10 (GND) - Body ground |
Always |
Below 1 Ω |
| OK | |
PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE |
| NG | |
REPAIR OR REPLACE HARNESS OR CONNECTOR |
PTC Heater Circuit
DESCRIPTION
PTC HTR heater relays are closed in accordance with signals from the air conditioning
amplifier assembly and power is supplied to the quick heater assembly installed
on the radiator h ...
Other materials:
Power Supply Drive Circuit (C1257)
DESCRIPTION
The motor relay (semiconductor relay) is built into the hydraulic brake booster
and drives the pump motor based on a signal from the skid control ECU (master cylinder
solenoid).
DTC No.
DTC Detecting Condition
Trouble Areas
C1257
...
Motor Circuit Malfunction (C1428)
DESCRIPTION
DTC No.
Detection Item
DTC Detection Condition
Trouble Area
C1428
Motor Circuit Malfunction
With the motor relay and motor fail-safe relay OFF, open or short in
motor circuit continues for 2 seconds o ...
How To Proceed With Troubleshooting
CAUTION / NOTICE / HINT
HINT:
The vehicle stability control system troubleshooting procedures are
based on the premise that the CAN communication system is functioning normally.
Check the CAN communication system first before troubleshooting the vehicle
stability control system ...
