Toyota Camry owners & service manuals

Toyota Camry (XV70): Low or High Power Supply Voltage (C1241)

Toyota Camry Repair Manual XV70 (2018-2024) / Drivetrain / Gf1a (transfer / 4wd / Awd) / Dynamic Torque Control Awd System / Low or High Power Supply Voltage (C1241)

DESCRIPTION

If a malfunction in the power source circuit occurs, or a malfunction in communication with the skid control ECU (brake actuator assembly) or in a speed sensor occurs, the 4WD ECU assembly will prohibit operations by the fail-safe function.

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

C1241

Low or High Power Supply Voltage
  1. When the following continues for 10 seconds or more:
    • At a vehicle speed of 3 km/h (2 mph) or more, voltage of IG1 terminal is 9.5 V or less.
  2. When either of the following is detected:
    • With the IG1 terminal voltage 9.5 V or less, communication with the skid control ECU (brake actuator assembly) is impossible.
    • Vehicle speed sensor voltage is reduced for 60 seconds or more.
  3. When the following continues for 3 seconds or more:
    • With the IG1 terminal voltage 17 V or more, communication with the skid control ECU (brake actuator assembly) is impossible.
  • Battery
  • Charging system
  • Wire harness or connector
  • Vehicle stability control system
  • CAN communication system
  • 4WD ECU assembly
DTC Detection Conditions: C1241
 

Vehicle Condition

Pattern 1

Pattern 2

Pattern 3

Pattern 4

Diagnosis Condition

At a vehicle speed of 3 km/h (2 mph) or more

○

-

-

-

With the IG1 terminal voltage 9.5 V or less

-

○

-

-

With the IG1 terminal voltage 17 V or more

-

-

-

○

Malfunction Status

Voltage of IG1 terminal is 9.5 V or less.

○

-

-

-

Communication with the skid control ECU (brake actuator assembly) is impossible.

-

○

-

○

Vehicle speed sensor voltage is reduced.

-

-

○

-

Detection Time

10 seconds or more

-

60 seconds or more

3 seconds or more

Number of Trips

1 trip

1 trip

1 trip

1 trip

HINT:

DTC will be output when conditions for any of the patterns in the table above are met.

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

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

PROCEDURE

1.

CHECK FOR DTC (CAN COMMUNICATION SYSTEM AND VEHICLE STABILITY CONTROL SYSTEM)

(a) Check if CAN communication system DTCs are output.

Click here

(b) Start the engine.

(c) Drive the vehicle, accelerate to a speed of 3 km/h (2 mph) or more for 60 seconds or more, and check if the speed sensor DTC (vehicle stability control system DTC) is output.

Chassis > Brake > Trouble Codes

Result

Proceed to

Neither CAN communication system DTC nor speed sensor DTC (vehicle stability control system DTC) is output

A

CAN communication system DTC is output

B

Speed sensor DTC (vehicle stability control system DTC) is output

C
B

GO TO CAN COMMUNICATION SYSTEM (HOW TO PROCEED WITH TROUBLESHOOTING)

C

REPAIR CIRCUIT INDICATED BY OUTPUT CODE (VEHICLE STABILITY CONTROL SYSTEM)

A

2.

INSPECT BATTERY

(a) Check the battery voltage.

Standard Voltage:

11 to 14 V

NG

CHECK CHARGING SYSTEM

OK

3.

CHECK HARNESS AND CONNECTOR (IG1 TERMINAL)

(a) Disconnect the K145 4WD ECU assembly connector.

*a

Front view of wire harness connector

(to 4WD ECU Assembly)

(b) Turn the ignition switch to ON.

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

Standard Voltage:

Tester Connection

Condition

Specified Condition

K145-3 (IG1) - Body ground

Ignition switch ON

11 to 14 V
NG

REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

4.

CHECK HARNESS AND CONNECTOR (GND TERMINAL)

(a) 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

K145-4 (GND) - Body ground

Always

Below 1 Ω
NG

REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

5.

RECONFIRM DTC

(a) Clear the DTC.

Chassis > Four Wheel Drive > Clear DTCs

(b) Start the engine.

(c) Drive the vehicle, accelerate to a speed of 3 km/h (2 mph) or more, and check if the same DTC is output.

Chassis > Four Wheel Drive > Trouble Codes

Result

Proceed to

DTC is output

A

DTC is not output

B

HINT:

Reinstall the sensor, connectors, etc. and restore the vehicle to its prior condition before rechecking DTCs.

A

REPLACE 4WD ECU ASSEMBLY

B

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