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:
Data list / active test
HINT:
By accessing the DATA LIST displayed by the intelligent
tester, you can perform such functions as reading the values
of switches and sensors without removing any parts. Reading
the DATA LIST as the first step in troubleshooting is one
method to shorten labor time.
1. DATA LIST FOR OCCUPA ...
Camshaft Position "A" - Timing Over
HINT:
If DTC P0011, P0012, P0021 or P0022 is present, check the VVT (Variable Valve
Timing) system.
DESCRIPTION
Refer to DTC P0010 (See page ES-75).
DTC No.
DTC Detection Condition
Trouble Area
P0011
P0021
Advanced cam timing:
With warm engine and engine spee ...
Reassembly
1. INSTALL 2ND BRAKE PISTON O-RING
(a) Coat 2 new O-rings with ATF, and install them in the
2nd brake piston.
NOTICE:
Make sure that the O-ring is not twisted or
pinched.
2. INSTALL 2ND BRAKE PISTON
(a) Coat the 2nd brake piston with ATF, and install it to
the 2nd brake cylinder.
NO ...
