Description of functions
The power steering computer assembly uses the input signal received from the torque sensor to detect the steering force. As part of the fail safe function, power assist is suspended when a torque sensor system malfunction is detected.
| DTC No. | Detected item | Inspection parts |
|---|---|---|
| C1511 | Torque sensor (TRQ1) signal malfunction, or interruption. | Torque sensor (integrated into the steering column assembly) Power steering computer assembly |
| C1512 | Torque sensor (TRQ2) signal malfunction, or interruption. | |
| C1513 | When the deviation of torque sensors TRQ1 and TRQ2 falls outside the specified value. | |
| C1514 | Torque sensor power supply voltage malfunction. | |
| C1517 | Provisional control continues for a long period of time due to a torque sensor system malfunction. |
Scheme 1
After replacement of the steering column assembly or power steering computer assembly, a diagnosis code is output (when the power steering computer assembly determines that torque sensor zero point calibration or rotation angle sensor output calibration have not been performed).
Calibration cannot be performed when the IG voltage is less than 9V.
| DTC No. | Detecting conditions | Action item |
|---|---|---|
| C1515 | Torque sensor zero point calibration not performed | Perform torque sensor zero point calibration. Operation is normal if a diagnosis code is not output. |
| C1525 | Rotation angle sensor output calibration not performed | Perform rotation angle sensor output calibration. Operation is normal if a diagnosis code is not output. |
A diagnosis code is output if the power steering computer assembly determines that torque sensor zero point calibration or rotation angle sensor output calibration have not been completed.
| DTC No. | Detecting conditions | Action item |
|---|---|---|
| C1516 | The torque sensor zero point calibration was not correctly completed due to a problem such as touching the steering mechanism. | Delete the diagnosis code, delete the sensor calibration value, and then perform torque sensor zero point calibration. Operation is normal if a diagnosis code is not output. |
| C1526 | The rotation angle sensor output calibration was not correctly completed. | Delete the diagnosis code, delete the sensor calibration value, and then perform rotation angle sensor output calibration. Operation is normal if a diagnosis code is not output. |
As part of the fail safe function, power assist is suspended while an ECM system error diagnosis code is being output. However, if only C1533, or C1534 are output, rather than suspending power assist, control is continued with a limited assist level.
| DTC No. | Detected item | Inspection parts |
|---|---|---|
| C1521 | Motor overcurrent malfunction | Power steering computer assembly |
| C1531 | ECM internal (microcomputer) malfunction | |
| C1532 | ECM internal (circuit) malfunction | |
| C1533 | ECM internal (temperature sensor) malfunction | |
| C1534 | ECM internal (EEPROM) malfunction | |
| C1554 | Power supply relay (integrated in ECM) malfunction |
As part of the fail safe function, power assist is suspended or limited when a motor error diagnosis code is being output.
| DTC No. | Detected item | Inspection parts |
|---|---|---|
| C1522 | Power supply current sensor malfunction | Power steering motor (integrated into the steering column assembly) Power steering computer assembly |
| C1523 | Excessive motor current deviation (difference between the command and feedback values) | |
| C1524 | Voltage malfunction or open circuit between motor terminals | |
| C1555 | Motor relay (integrated in ECM) malfunction |
Scheme 2
As part of the fail safe function, power assist is suspended when a motor rotation angle sensor malfunction diagnosis code is being output.
| DTC No. | Detected item | Inspection parts |
|---|---|---|
| C1528 | Motor rotation angle sensor malfunction | Motor rotation angle sensor (integrated into the steering column assembly) Power steering computer assembly |
Scheme 3
The power steering computer assembly uses CAN communication to input the vehicle speed signal from the skid control computer (brake actuator assembly).
| DTC No. | Detected item | Inspection parts |
|---|---|---|
| C1541 | Vehicle speed signal abnormal | Speed sensor system Vehicle stability control system CAN communication system Power steering computer assembly |
As part of the fail safe function, power assist is suspended or limited when there is a power supply system malfunction.
| DTC No. | Detected item | Inspection parts |
|---|---|---|
| C1551 | IG power supply circuit is open or shorted. | Power steering computer assembly Power supply system ECM IG1 fuse Wiring harness or connector |
Scheme 4
As part of the fail safe function, power assist is suspended when there is a PIG power supply malfunction.
| DTC No. | Detected item | Inspection parts |
|---|---|---|
| C1552 | PIG power supply voltage malfunction | EPS fuse Power steering computer assembly Wiring harness or connector |
Scheme 5
The power steering computer assembly uses CAN communication to input the signals from the engine control computer and skid control computer (brake actuator assembly).
| DTC No. | Detected item | Inspection parts |
|---|---|---|
| U0100 | Engine control computer communication malfunction. | CAN communication system Engine control computer |
| U0122 | Skid control computer (brake actuator assembly) communication malfunction. | CAN communication system Skid control computer (brake actuator assembly) |
| U0416 | Reception of an error signal from the skid control computer (brake actuator assembly). |
With normal diagnosis code output, troubleshooting is recorded if the P/S warning light remains on.
When the power supply voltage input circuit (IG and PIG) for the power steering computer assembly is open, the P/S warning light remains on.
Scheme 6
See also:
• WHEEL AND TIRE SYSTEM
• FRONT WHEEL ALIGNMENT
• INSPECTION