C1241

BRAKE CONTROL / DYNAMIC CONTROL SYSTEMS: VEHICLE STABILITY CONTROL SYSTEM: C1241: Low Power Supply Voltage Malfunction
C1241 - Low Power Supply Voltage Malfunction

DESCRIPTION

If a malfunction is detected in the power supply circuit, the skid control ECU stores this DTC and the fail-safe function prohibits ABS operation.

This DTC is stored when the +BS terminal voltage meets one of the DTC detection conditions due to a malfunction in the power supply or charging circuit such as the battery or alternator circuit, etc.

The DTC is canceled when the +BS terminal voltage returns to normal.





*: The skid control ECU monitors the resistance of the power source line at the +BS terminal. A malfunction is detected when an abnormality occurs in the +BS terminal wire harness or its connection and the skid control ECU determines that the wiring resistance at the +BS terminal exceeds the standard resistance.

WIRING DIAGRAM





INSPECTION PROCEDURE

NOTICE:
Inspect the fuses for circuits related to this system before performing the following inspection procedure.

PROCEDURE

1. CHECK BATTERY

(a) Check the battery voltage.

Standard Voltage:

11 to 14 V

Result:





B -- CHECK OR REPLACE CHARGING SYSTEM COMPONENT OR BATTERY Component Tests and General Diagnostics

C -- CHECK OR REPLACE CHARGING SYSTEM COMPONENT OR BATTERY Component Tests and General Diagnostics
A -- Continue to next step.

2. CHECK HARNESS AND CONNECTOR (POWER SOURCE 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 connector.

(c) Measure the voltage according to the value(s) in the table below.

Standard Voltage:





Text in Illustration





Result:





B -- CHECK HARNESS AND CONNECTOR (SKID CONTROL ECU - ENGINE ROOM RELAY BLOCK AND JUNCTION BLOCK ASSEMBLY)

C -- REPAIR OR REPLACE HARNESS OR CONNECTOR (IG1 CIRCUIT)
A -- Continue to next step.

3. CHECK HARNESS AND CONNECTOR (GND1 TERMINAL)

(a) Turn the ignition switch off.





(b) Measure the resistance according to the value(s) in the table below.

Standard Resistance:





Text in Illustration





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (GND1 CIRCUIT)
OK -- Continue to next step.

4. RECONFIRM DTC

(a) Reconnect the skid control ECU connector.

(b) Clear the DTCs Reading and Clearing Diagnostic Trouble Codes.

(c) Turn the ignition switch off.

(d) Start the engine.

(e) Perform a road test.

(f) Check if the same DTC is output Reading and Clearing Diagnostic Trouble Codes.

Result:





HINT
If troubleshooting has been carried out according to Problem Symptoms Table, refer back to the table and proceed to the next step before replacing parts Problem Symptoms Table.

B -- REPLACE BRAKE ACTUATOR ASSEMBLY Removal

A -- CHECK FOR INTERMITTENT PROBLEMS How To Proceed With Troubleshooting

5. CHECK HARNESS AND CONNECTOR (SKID CONTROL ECU - ENGINE ROOM RELAY BLOCK AND JUNCTION BLOCK ASSEMBLY)

(a) Turn the ignition switch off.

(b) Disconnect the engine room relay block and junction block assembly connector.

(c) Measure the resistance according to the value(s) in the table below.

Standard Resistance:





HINT
* Even if the resistance between the skid control ECU and the engine room relay block and junction block assembly is normal, there may be an abnormality in the resistance of the wiring between the battery and the engine room relay block and junction block assembly. Therefore, be sure to inspect the circuit between the battery and the engine room relay block and junction block assembly before replacing the skid control ECU (brake actuator assembly).
* If troubleshooting has been carried out according to Problem Symptoms Table, refer back to the table and proceed to the next step before replacing parts Problem Symptoms Table.

NG -- REPAIR OR REPLACE WIRE HARNESS OR ENGINE ROOM RELAY BLOCK AND JUNCTION BLOCK ASSEMBLY

OK -- REPLACE BRAKE ACTUATOR ASSEMBLY Removal