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 |
|---|---|---|---|
| C1241/94 | Low Power Supply Voltage |
|
|
WIRING DIAGRAM
CAUTION / NOTICE / HINT
Note
Inspect the fuses for circuits related to this system before performing the following inspection procedure.
When the 4WD ECU assembly is replaced with a normal one from another vehicle, it is necessary to perform calibration.
PROCEDURE
CHECK FOR DTC (CAN COMMUNICATION SYSTEM AND BRAKE CONTROL SYSTEM)
Check if the CAN communication system DTC is output.
Start the engine.
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 (brake control system DTC) is output.
| Result | ||||||||
|---|---|---|---|---|---|---|---|---|
|
Tech Tips
When DTCs indicating a CAN communication system malfunction are output, repair the CAN communication system before repairing each corresponding sensor.
| B |
|
GO TO CAN COMMUNICATION SYSTEM (HOW TO PROCEED WITH TROUBLESHOOTING) Click here |
| C |
|
REPAIR CIRCUIT INDICATED BY OUTPUT CODE (BRAKE CONTROL SYSTEM) Click here |
| A |
|
INSPECT BATTERY
Check the battery voltage.
| Standard voltage |
|---|
| 11 to 14 V |
| Result | |||
|---|---|---|---|
|
| NG |
|
CHECK CHARGING SYSTEM for 8AR-FTS: Click here |
| OK |
|
CHECK HARNESS AND CONNECTOR (IG1 TERMINAL)
| *a | Front view of wire harness connector (to 4WD ECU Assembly) |
Disconnect the I55 4WD ECU 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 |
| OK |
|
CHECK HARNESS AND CONNECTOR (GND TERMINAL)
Turn the engine switch off.
| *a | Front view of wire harness connector (to 4WD ECU Assembly) |
Measure the resistance according to the value(s) in the table below.
| Standard Resistance | ||||||
|---|---|---|---|---|---|---|
|
| Result | |||
|---|---|---|---|
|
| NG |
|
REPAIR OR REPLACE HARNESS OR CONNECTOR |
| OK |
|
RECONFIRM DTC
Reconnect the I55 4WD ECU assembly connector.
Clear the DTCs.
Start the engine.
Drive the vehicle, accelerate to a speed of 3 km/h (2 mph) or more for 60 seconds or more, and check if the same DTC is output.
| Result | |||
|---|---|---|---|
|
Tech Tips
Reinstall the sensor, connectors, etc. and restore the vehicle to its prior condition before rechecking DTCs.
| DTC is output |
|
REPLACE 4WD ECU ASSEMBLY for LHD: Click here |
| DTC is not output |
|
CHECK FOR INTERMITTENT PROBLEMS Click here |