DESCRIPTION
- The 4WD ECU assembly receives the signals sent from the ECM, skid control ECU (brake actuator assembly) and steering sensor via CAN communication.
- When DTCs indicating a CAN communication system malfunction are output, repair the CAN communication system before repairing each corresponding sensor.
| DTC No. | Detection Item | DTC Detection Condition | Trouble Area | Warning Indicate | Memory |
|---|---|---|---|---|---|
| U0073/86 | Control Module Communication Bus OFF | When the following condition continues for 5 seconds or more: Signals from the 4WD ECU assembly are not received. When the following condition occurs 10 times consecutively: A communication malfunction (bus off) occurs one or more times within 0.1 seconds. | Wire harness (CANL, CANH circuit) 4WD ECU assembly | Comes on | DTC stored |
| U0100/85 | Lost Communication with ECM / PCM "A" | When both of the following conditions continue for 2 seconds or more: The voltage at terminal IG1 is 10 V or more. At a vehicle speed of 60 km/h (38 mph) or more, communication with the ECM cannot be performed. | Wire harness (CANL, CANH circuit) 4WD ECU assembly ECM | Does not come on | DTC stored |
| U0126/84 | Lost Communication with Steering Angle Sensor Module | When both of the following conditions continue for 1 second or more: The voltage of the IG1 terminal is 10 V or more. Communication with the steering sensor cannot be performed. When both of the following conditions occur 10 times consecutively: The voltage at terminal IG1 is 10 V or more. The condition that communication with the steering sensor cannot be performed occurs once within 5 seconds. | Wire harness (CANL, CANH circuit) 4WD ECU assembly Steering sensor | Does not come on | DTC stored |
| U0129/83 | Lost Communication with Brake System Control Module | When both of the following conditions continue for 3 seconds or more: The voltage at terminal IG1 is 10 V or more. Communication with the skid control ECU (brake actuator assembly) cannot be performed. | Wire harness (CANL, CANH circuit) 4WD ECU assembly Skid control ECU (brake actuator assembly) | Comes on | DTC stored |
- If wheel slip continues, differential control will be disabled when the torque-distribution ratio of the differential clutch exceeds the set value and a malfunction in the output of the wheel speed sensors, etc. occurs.
- If a difference in diameter between the front and rear wheels is determined, differential control will be disabled.
| DTC No. | Detection Item | DTC Detection Condition | Trouble Area | Warning Indicate | Memory |
|---|---|---|---|---|---|
| C1299/99 | Cancellation of 4WD Control | When either of the following conditions is detected: The torque-distribution ratio of the differential clutch exceeds the set value. The vehicle is driven with different size tires on the front and rear. | Tire size and tire pressure Brake control system Suspension or drivetrain-related parts 4WD ECU assembly Automatic transmission with transfer assembly | Comes on | DTC stored |
The 4WD ECU assembly receives signals from each sensor to control clutch fluid pressure for limiting the center differential operation, which distributes torque according to the driving conditions.
| DTC No. | Detection Item | DTC Detection Condition | Trouble Area | Warning Indicate | Memory |
|---|---|---|---|---|---|
| C1298/98 | Linear Solenoid Circuit | When all of the following conditions continue for 1 second or more: IG1 terminal voltage is 9.5 V or more. Operation command current for the linear solenoid (transfer control solenoid) is 3.5 A or more. Open or short in the SLC+ or SLC- circuit. | Transfer transmission wire Harness or connector Transfer control solenoid assembly 4WD ECU assembly | Comes on | DTC stored |
Scheme 79
- The 4WD ECU assembly determines that the vehicle is turning based on the signals sent from the steering sensor.
- The steering sensor signal is sent to the 4WD ECU assembly via CAN communication.
- The 4WD ECU assembly detects the amount of steering wheel movement and performs "slip control at vehicle start up", according to the amount of movement and "slip control" to secure high turning performance.
| DTC No. | Detection Item | DTC Detection Condition | Trouble Area | Warning Indicate | Memory |
|---|---|---|---|---|---|
| C1297/97 | Steering Angle Sensor | When the voltage of the 4WD ECU assembly IG1 terminal is 9.5 V or more, the steering sensor malfunction signal is received. | Steering sensor CAN communication system Brake control system 4WD ECU assembly | Does not come on | DTC stored |
If a malfunction in the speed sensor signal circuit occurs, the 4WD ECU assembly will output this DTC. When slipping is detected based on signals sent from the 4 vehicle speed sensors, the 4WD ECU assembly controls torque distribution between front and rear wheels according to the amount of slipping.
| DTC No. | Detection Item | DTC Detection Condition | Trouble Area | Warning Indicate | Memory |
|---|---|---|---|---|---|
| C1296/96 | ABS Malfunction | When the following condition is met: A wheel speed sensor malfunction is received from skid control ECU (brake actuator assembly). | Brake control system (speed sensor circuit) 4WD ECU assembly | Comes on | DTC stored |
This DTC is output by the 4WD ECU assembly if a malfunction occurs in the linear solenoid power supply system.
| DTC No. | Detection Item | DTC Detection Condition | Trouble Area | Warning Indicate | Memory |
|---|---|---|---|---|---|
| C120C/79 | Linear Solenoid Power Supply System Malfunction | When the 4WD relay is on, the 4WD relay monitor remains off for 1 second or more while the voltage at the IG1 terminal is 9.5 V or more. While the 4WD relay is off, the 4WD relay monitor remains on for 1 second or more immediately after the engine switch is on (IG). | IG1 No. 2 fuse Wire harness or connector (IG1 circuit, GND circuit) 4WD ECU assembly | Comes on | DTC stored |
Scheme 80
If a malfunction in the power source circuit or a malfunction in communication with the skid control ECU (brake actuator assembly) or a speed sensor occurs, the 4WD ECU assembly will prohibit operations through the fail-safe function.
| DTC No. | Detection Item | DTC Detection Condition | Trouble Area | Warning Indicate | Memory |
|---|---|---|---|---|---|
| C1241/94 | Low Power Supply Voltage | When the following condition is detected: At a vehicle speed of 3 km/h (2 mph) or more, the voltage at terminal IG1 is 9.5 V or less. When either of the following conditions is detected: With IG1 terminal voltage at 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. When the following condition is detected for 3 seconds or more: With IG1 terminal voltage at 17 V or more, communication with the skid control ECU (brake actuator assembly) is impossible. | IG1 No. 2 fuse Battery Charging system Harness or connector (IG1 circuit, GND circuit) Brake control system (speed sensor circuit) CAN communication system 4WD ECU assembly | Comes on | DTC stored |
Scheme 81
The 4WD ECU assembly is connected to the combination meter assembly via the CAN communication system. If any of the following conditions is detected, the multi-information display indicates a malfunction in the four-wheel drive control system.
- There is a malfunction in the 4WD ECU assembly internal circuit.
- A low voltage is applied to the power source for the 4WD ECU assembly.
- There is a malfunction in the CAN communication system.
- There is a malfunction in the brake control system.
- During fail-safe function.
Scheme 82
Refer to "AWD Warning Remains ON".
Refer to AWD Warning Remains ON [04/2013 - ]
Connecting terminals TC and CG of the DLC3 causes the 4WD ECU assembly to display a DTC on the multi-information display.
Scheme 83
See also:
• INSPECTION [04/2013 - ]
• DIAGNOSIS SYSTEM [04/2013 - ]