DESCRIPTION
The motor relay and motor fail-safe relay are built into the brake actuator assembly.
During ABS, TRAC, VSC, or brake assist operation, the skid control ECU (brake actuator assembly) turns on the motor relay to run the pump motor in the brake actuator assembly.
When a motor system DTC is stored, the motor fail-safe relay cuts the power source supply to the motor relay for fail-safe operation.
These DTCs may be stored when the voltage to the motor relay power source (BM terminal) is lower than the DTC detection condition due to low output from the battery or alternator.
DTC No. |
Detection Item |
DTC Detection Condition |
Trouble Area |
---|---|---|---|
C142B |
Motor Power Supply Voltage Circuit |
When voltage at +BS terminal is 9.5 V or higher, open in BM terminal continues for 1 second or more. |
|
C146C |
Open in ABS Motor Relay Circuit |
When voltage at +BS terminal is 9.5 V or higher and motor relay ON while control operates, relay contact OFF condition continues for 0.12 seconds or more. |
|
C146D |
Short in ABS Motor Relay Circuit |
Either of the following is detected:
|
|
HINT:
DTC will be output when conditions for either of the patterns in the table above are met.
WIRING DIAGRAM
CAUTION / NOTICE / HINT
NOTICE:
HINT:
When C1241 and/or C1417 is output together with C142B, C146C and/or C146D inspect and repair the trouble areas indicated by C1241 and/or C1417 first.
PROCEDURE
1. |
CHECK TERMINAL VOLTAGE (BM TERMINAL) |
(a) Turn the ignition switch off.
(b) Make sure that there is no looseness at the locking part and the connecting part of the connectors.
(c) Disconnect the S1 skid control ECU (brake actuator assembly) connector. |
|
(d) Measure the voltage according to the value(s) in the table below.
Standard Voltage:
Tester Connection |
Switch Condition |
Specified Condition |
---|---|---|
S1-13 (BM) - Body ground |
Always |
11 to 14 V |
*a |
Front view of wire harness connector (to Skid Control ECU [Brake Actuator Assembly]) |
NG |
REPAIR OR REPLACE HARNESS OR CONNECTOR (BM CIRCUIT) |
|
2. |
CHECK HARNESS AND CONNECTOR (GND2 TERMINAL) |
(a) Measure the resistance according to the value(s) in the table below. Standard Resistance:
|
|
NG |
REPAIR OR REPLACE HARNESS OR CONNECTOR (GND2 CIRCUIT) |
|
3. |
RECONFIRM DTC |
HINT:
These codes are stored when a problem is identified in the skid control ECU (brake actuator assembly). The motor relay is in the skid control ECU (brake actuator assembly). Therefore, motor relay inspections and motor relay unit inspections cannot be performed. Be sure to check if any DTCs are output before replacing the brake actuator assembly.
(a) Reconnect the S1 skid control ECU (brake actuator assembly) connector.
(b) Clear the DTC (See page ).
(c) Turn the ignition switch off.
(d) Start the engine.
(e) Drive the vehicle at a speed of 20 km/h (12 mph) or more for 30 seconds or more.
(f) Check if the same DTC is recorded (See page ).
Result
Result |
Proceed to |
---|---|
DTCs C142B, C146C and C146D are not output |
A |
DTCs C142B, C146C and/or C146D are output |
B |
HINT:
A |
USE SIMULATION METHOD TO CHECK |
B |
REPLACE BRAKE ACTUATOR ASSEMBLY |
Parts Location
PARTS LOCATION
ILLUSTRATION
*A
for Access Cab
*B
w/ Washer Fluid Level Warning
*C
w/ Tire Pressure Warning System
*D
for Manual Transmission
*E
for Hydraulic Booster Type
...
Diagnostic Trouble Code Chart
DIAGNOSTIC TROUBLE CODE CHART
HINT:
If a trouble code is stored during the DTC check, inspect the trouble areas listed
for that code. For details of the code, refer to "See page" below.
Transponder Key ECU Assembly
DTC Code
Detection Item
See page
...
Installation
INSTALLATION
PROCEDURE
1. INSTALL REAR BRAKE DRUM SUB-ASSEMBLY
(a) Install a new drum gasket onto the rear brake drum.
(b) Install the rear brake drum.
2. ADJUST REAR DRUM BRAKE SHOE CLEARANCE
(a) Provisionally install the hub nuts.
(b) Remove the hole plug, and turn the adjuster to expand ...