Toyota Tacoma (2015-2018) Service Manual: IG Supply Voltage Low (C120B)
DESCRIPTION
|
DTC No. |
Detection Item |
DTC Detection Condition |
Trouble Area |
|---|---|---|---|
|
C120B |
IG Supply Voltage Low |
Master cylinder pressure sensor power supply voltage decrease occurs or history of voltage decrease exists, and defective master cylinder pressure sensor output continues for 1 second or more. |
|
WIRING DIAGRAM
Refer to DTC C1417 (See page .gif)
).
CAUTION / NOTICE / HINT
NOTICE:
- When replacing the skid control ECU (brake actuator assembly), perform
zero point calibration and store system information (See page
).
- Inspect the fuses for circuits related to this system before performing the following procedure.
PROCEDURE
|
1. |
CHECK HARNESS AND CONNECTOR (+BS TERMINAL) |
|
(a) Make sure that there is no looseness at the locking part and the connecting part of the connector. |
|
(b) Disconnect the skid control ECU (brake actuator assembly) connector.
(c) Measure the voltage according to the value(s) in the table below.
Standard Voltage:
|
Tester Connection |
Condition |
Specified Condition |
|---|---|---|
|
S1-38 (+BS) - Body ground |
Always |
11 to 14 V |
|
S1-38 (+BS) - S1-25 (GND1) |
Always |
11 to 14 V |
|
*a |
Front view of wire harness connector (to Skid Control ECU [Brake Actuator Assembly]) |
| NG | .gif) |
REPAIR OR REPLACE HARNESS OR CONNECTOR (+BS CIRCUIT) |
|
.gif)
|
2. |
RECONFIRM DTC |
(a) Reconnect the S1 skid control ECU (brake actuator assembly) connector.
(b) Clear the DTCs (See page
).
(c) Check if the same DTC is recorded (See page
).
|
Result |
Proceed to |
|---|---|
|
DTC C120B is not output. |
A |
|
DTC C120B is output. |
B |
| A | |
USE SIMULATION METHOD TO CHECK |
| B | |
REPLACE BRAKE ACTUATOR ASSEMBLY |
Control Module Communication Bus OFF (U0073,U0100,U0124,U0126)
DESCRIPTION
The skid control ECU (brake actuator assembly) receives the signals from the
ECM, steering angle sensor (spiral cable with sensor sub-assembly), 4 wheel drive
control ECU*, and yaw ra ...
Zero Point Calibration of Yaw Rate Sensor Undone (C1210,C1336)
DESCRIPTION
The skid control ECU (brake actuator assembly) receives signals from the yaw
rate and acceleration sensor (airbag sensor assembly) via the CAN communication
system.
The airbag sensor ...
Other materials:
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 ...
If the shift lever cannot be shifted from P (vehicles with an automatic transmission)
If the shift lever cannot be shifted with your foot on the brake, there may
be a problem with the shift lock system (a system to prevent accidental operation
of the shift lever). Have the vehicle inspected by your Toyota dealer immediately.
The following steps may be used as an emergency measur ...
Open in Bus 3 Main Bus Line
DESCRIPTION
There may be an open circuit in one of the CAN main bus lines when the resistance
between terminals 6 (CA3H) and 21 (CA3L) of the central gateway ECU (network gateway
ECU) is 70 Ω or higher.
Detection Item
Trouble Area
Resistance between term ...
