Toyota Sienna Service Manual: Low Battery Positive Voltage
DTC C1241/41 Low Battery Positive Voltage
DESCRIPTION
If there is a problem with the brake actuator assembly (skid control ECU) power supply circuit, the skid control ECU outputs the DTC and prohibits the ABS operation with the fail safe function.
If the voltage supplied to the IG1 terminal is not within the DTC detection threshold due to malfunctions in such as the battery and alternator circuit, this DTC is stored.
WIRING DIAGRAM
INSPECTION PROCEDURE
HINT: After steps 1 and 2 are completed, start the inspection from step 3 when using the intelligent tester, and from step 4 when not using the intelligent tester.
1 INSPECT BATTERY
(a) Check the battery voltage.
Standard voltage: 11 to 14 V
2 INSPECT FUSE (ECU-IG FUSE)
(a) Remove the ECU-IG fuse from the driver side J/B.
(b) Measure the resistance according to the value(s) in the table below.
Standard resistance
3 READ VALUE OF INTELLIGENT TESTER (IG1 POWER SUPPLY)
(a) Install the ECU-IG fuse.
(b) Connect the intelligent tester to the DLC3.
(c) Turn the ignition switch to the ON position and turn the intelligent tester main switch on.
(d) Start the engine.
(e) Select the DATA LIST mode on the intelligent tester.
ABS:
(f) Measure the voltage output from the ECU displayed on the intelligent tester.
OK: "Normal" is displayed.
4 INSPECT SKID CONTROL ECU (IG1 TERMINAL VOLTAGE)
(a) Disconnect the skid control ECU connector.
(b) Turn the ignition switch to ON position.
(c) Measure the voltage according to the value(s) in the table below.
Standard voltage 
5 INSPECT SKID CONTROL ECU (GND TERMINAL CONTINUITY)
(a) Turn the ignition switch off.
(b) Measure the resistance according to the value(s) in the table below.
Standard resistance
6 RECONFIRM DTC
(a) Clear the DTCs (See page BC-10).
(b) Check that the same DTC is recorded (See page BC- 10).
HINT: Reinstall the sensors, connectors, etc. and restore the vehicle to its prior condition before rechecking for DTCs.
Result
REPLACE BRAKE ACTUATOR ASSEMBLY
Open in ABS Solenoid Relay Circuit
DESCRIPTION
This relay supplies power to each ABS solenoid.
Immediately after the ignition switch is turned to the ON position, the relay
turns on if the solenoid is
determined to be normal ...
Open in Stop Light Switch Circuit
DTC C1249/49 Open in Stop Light Switch Circuit
DESCRIPTION
This skid control ECU inputs the stop light switch signal and detects the
status of brake operation.
The skid control ECU has an open ...
Other materials:
Rear Airbag Sensor RH Circuit Malfunction
DTC B1154/38 Rear Airbag Sensor RH Circuit Malfunction
DESCRIPTION
The rear airbag sensor RH circuit consists of the center airbag sensor
assembly and rear airbag sensor
RH.
If the center airbag sensor assembly receives signals from the rear airbag
sensor RH, it judges whether or
not the ...
Freeze frame data
1. FREEZE FRAME DATA
(a) The vehicle (sensor) status, stored during ABS and/
or VSC operation or at the time of an error code
detection, can be displayed by the intelligent tester.
(b) Only one record of freeze frame data is stored and
the freeze frame data generated during ABS and/or
VSC op ...
Diagnosis system
1. CHECK DLC3
The ECU uses ISO 15765-4 for communication.
The terminal arrangement of the DLC3 complies
with SAE J1962 and meets the ISO 15765-4 format.
NOTICE:
*: Before measuring the resistance, leave the
vehicle as is for at least 1 minute and do not
operate the ignition s ...
