BRAKE CONTROL / DYNAMIC CONTROL SYSTEMS  ANTI-LOCK BRAKE SYSTEM  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 IG1 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 IG1 terminal voltage returns to normal.

DTC No. Detection Item DTC Detection Condition Trouble Area
C1241 Low Power Supply Voltage Malfunction Any of the following is detected:
1.

At a vehicle speed of 3 km/h (2 mph) or more, the IG1 terminal voltage is less than 9.5 V for 10 seconds or more.

2.

When the ABS solenoid relay remains on and the IG1 terminal voltage is less than 9.5 V, the relay contact is open for 0.22 seconds or more.

3.

With the IG1 terminal voltage 9.5 V or less, the vehicle speed sensor power supply decreases for 60 seconds or more.


·

ECU-IG NO. 1 fuse

·

Battery

·

Charging system

·

Power source circuit

·

Internal power supply circuit of the skid control ECU (brake actuator assembly)



WIRING DIAGRAM

C274775E12
0.75,0.99 2.167,1.167 1.417,0.177 10 false from IG1 NO. 1 Relay 3.635,1.167 4.573,1.333 0.938,0.167 10 false ECU-IG NO. 1 5.948,1 6.25,1.167 0.302,0.167 10 false IG1 5.698,0.906 5.948,1.073 0.25,0.167 10 false 34 5.948,2.729 6.417,2.917 0.469,0.188 10 false GND1 5.75,2.625 5.917,2.833 0.167,0.208 10 false 1 5.5,3.708 5.844,3.906 0.344,0.198 10 false A48 5.5,3.885 7.073,4.219 1.573,0.333 10 false Skid Control ECU (Brake Actuator Assembly) 4.198,0.875 4.354,1.073 0.156,0.198 10 false 2 3.771,0.875 3.927,1.073 0.156,0.198 10 false 1

CAUTION / NOTICE / HINT

NOTICE:

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


PROCEDURE

1.CHECK BATTERY
a.

Check the battery voltage.

Standard Voltage:

11 to 14 V



Result:
Proceed to
OK
NG



OK

2.CHECK HARNESS AND CONNECTOR (IG1 TERMINAL)

NG

CHECK OR REPLACE CHARGING SYSTEM OR BATTERY

for 1ZR-FE: Click herePower Source / Network>1ZR-FE BATTERY / CHARGING>CHARGING SYSTEM>ON-VEHICLE INSPECTION

for 2ZR-FE: Click herePower Source / Network>2ZR-FE BATTERY / CHARGING>CHARGING SYSTEM>ON-VEHICLE INSPECTION

for 2NZ-FE: Click herePower Source / Network>2NZ-FE BATTERY / CHARGING>CHARGING SYSTEM>ON-VEHICLE INSPECTION


2.CHECK HARNESS AND CONNECTOR (IG1 TERMINAL)
a.
C277404C14
0.167,1 0.583,1.25 0.417,0.25 0.76,1.844 1.156,1.042 false 2.49,1.865 2.281,1.323 false 0.25,1.042 0.708,1.24 0.458,0.198 10 false A48 0.104,0.104 0.417,0.302 0.313,0.198 10 false *a 0.531,1.875 1.146,2.073 0.615,0.198 10 false GND1 2.365,1.896 2.979,2.094 0.615,0.198 10 false IG1
*a Front view of wire harness connector
(to Skid Control ECU (Brake Actuator Assembly))


Make sure that there is no looseness at the locking part and the connecting part of the connector.


b.

Disconnect the A48 skid control ECU (brake actuator assembly) connector.


c.

Turn the ignition switch to ON.


d.

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

Standard Voltage:
Tester Connection Condition Specified Condition
A48-34 (IG1) - Body ground Ignition switch ON 11 to 14 V
A48-34 (IG1) - A48-1 (GND1) Ignition switch ON 11 to 14 V



Result:
Proceed to
OK
NG



OK

3.CHECK HARNESS AND CONNECTOR (GND1 TERMINAL)

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR (IG1 CIRCUIT)

3.CHECK HARNESS AND CONNECTOR (GND1 TERMINAL)
a.
C277404C15
0.167,1 0.583,1.25 0.417,0.25 0.76,1.844 1.156,1.042 false 0.26,1.042 0.719,1.24 0.458,0.198 10 false A48 0.104,0.104 0.417,0.302 0.313,0.198 10 false *a 0.531,1.875 1.146,2.073 0.615,0.198 10 false GND1
*a Front view of wire harness connector
(to Skid Control ECU (Brake Actuator Assembly))


Turn the ignition switch off.


b.

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

Standard Resistance:
Tester Connection Condition Specified Condition
A48-1 (GND1) - Body ground Always Below 1 Ω



Result:
Proceed to
OK
NG



OK

4.RECONFIRM DTC

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR (GND1 CIRCUIT)

4.RECONFIRM DTC
a.

Reconnect the A48 skid control ECU (brake actuator assembly) connector.


b.

Clear the DTCs.

Click hereBrake>BRAKE CONTROL / DYNAMIC CONTROL SYSTEMS>ANTI-LOCK BRAKE SYSTEM>DTC CHECK / CLEAR

Chassis > ABS/VSC/TRC > Clear DTCs
50002 105

c.

Turn the ignition switch off.


d.

Start the engine.


e.

Perform a road test.


f.

Check if the same DTC is output.

Click hereBrake>BRAKE CONTROL / DYNAMIC CONTROL SYSTEMS>ANTI-LOCK BRAKE SYSTEM>DTC CHECK / CLEAR

Chassis > ABS/VSC/TRC > Trouble Codes
50001 105
Result:
Result Proceed to
DTC C1241 is not output. A
DTC C1241 is output. B


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.

Click hereBrake>BRAKE CONTROL / DYNAMIC CONTROL SYSTEMS>ANTI-LOCK BRAKE SYSTEM>PROBLEM SYMPTOMS TABLE




A

USE SIMULATION METHOD TO CHECK

Click hereGeneral>INTRODUCTION>HOW TO TROUBLESHOOT ECU CONTROLLED SYSTEMS>HOW TO PROCEED WITH TROUBLESHOOTING


B

REPLACE BRAKE ACTUATOR ASSEMBLY

Click hereBrake>BRAKE CONTROL / DYNAMIC CONTROL SYSTEMS>BRAKE ACTUATOR>REMOVAL