DTC Code | DTC Name |
---|---|
C1241 | Low Power Supply Voltage Malfunction |
DESCRIPTION
If a malfunction is detected in the power supply circuit, the skid control ECU (brake actuator assembly) stores this DTC and the fail-safe function prohibits ABS operation.
This DTC is stored when the +BS terminal voltage deviates due to a malfunction in the power supply or charging circuit such as the battery or alternator circuit, etc.
The DTC is cleared when the +BS terminal voltage returns to normal.
DTC No. | Detection Item | DTC Detection Condition | Trouble Area | Note |
---|---|---|---|---|
C1241 | Low Power Supply Voltage Malfunction | Any of the following is detected:
|
|
- |
Vehicle Condition | |||||
---|---|---|---|---|---|
Pattern 1 | Pattern 2 | Pattern 3 | Pattern 4 | ||
Diagnosis Condition | - | - | - | - | - |
Malfunction Status | At a vehicle speed of 3 km/h (2 mph) or more, the +BS terminal voltage is less than 9.5 V | ○ | - | - | - |
When the ABS solenoid relay remains on and the +BS terminal voltage is less than 9.5V, the relay contact is open | - | ○ | - | - | |
With the +BS terminal voltage 9.5 V or less, the vehicle speed sensor power supply decreases | - | - | ○ | - | |
When fail-safe motor relay is on and +BS terminal voltage is below 9.5 V, fail-safe motor relay overcurrent continues | - | - | - | ○ | |
Detection Time | 10 seconds or more. | 0.22 seconds or more. | 60 seconds or more. | 0.05 seconds or more. | |
Number of Trips | 1 trip | 1 trip | 1 trip | 1 trip |
Tech Tips
DTC will be output when conditions for either of the patterns in the table above are met.
WIRING DIAGRAM
*1 | from IG circuit |
*2 | VSC NO. 2 |
*3 | Skid Control ECU (Brake Actuator Assembly) |
CAUTION / NOTICE / HINT
Note
When replacing the skid control ECU (brake actuator assembly), perform zero point calibration and store system information.
Inspect the fuses for circuits related to this system before performing the following procedure.
PROCEDURE
CHECK BATTERY
Check the battery voltage.
Standard Voltage | ||||||
---|---|---|---|---|---|---|
|
Result | |||
---|---|---|---|
|
NG |
CHECK OR REPLACE CHARGING SYSTEM OR BATTERY for 8GR-FKS: Click here |
OK |
CHECK TERMINAL VOLTAGE (+BS TERMINAL)
Turn the engine switch off.
Make sure that there is no looseness in the locking part and connecting part of the connectors.
Disconnect the A9 skid control ECU (brake actuator assembly) connector.
Turn the engine switch on (IG).
Measure the voltage according to the value(s) in the table below.
Standard Voltage | ||||||
---|---|---|---|---|---|---|
|
Result | |||
---|---|---|---|
|
NG |
REPAIR OR REPLACE HARNESS OR CONNECTOR (+BS CIRCUIT) |
OK |
CHECK HARNESS AND CONNECTOR (GND1 TERMINAL)
Turn the engine switch off.
Measure the resistance according to the value(s) in the table below.
Standard Resistance | ||||||
---|---|---|---|---|---|---|
|
Result | |||
---|---|---|---|
|
NG |
REPAIR OR REPLACE HARNESS OR CONNECTOR (GND1 CIRCUIT) |
OK |
RECONFIRM DTC
Reconnect the A9 skid control ECU (brake actuator assembly) connector.
Clear the DTCs.
Turn the engine switch off.
Start the engine.
Perform a road test.
Check if the same DTC is output.
Result | ||||||
---|---|---|---|---|---|---|
|
A |
USE SIMULATION METHOD TO CHECK Click here |
B |
REPLACE BRAKE ACTUATOR ASSEMBLY for LHD: Click here |