ESP CM measures operating torque using torque sensor when driver operates steering wheel. The EPS CM controls the current of EPS motor in proportion to vehicle speed and operating torque of steering wheel. ESP CM, at times, supplies or cuts off current (as determined by engine control relay fail safe relay inside EPS CM) to EPS motor operating source and system source.
Detecting Condition | Threshold Value | Diagnostic Time | Fail Safe | Possible Cause | |||
Motor | Relay | Fail lamp | Restoration condition | ||||
Before Fail safe relay operating | Fail safe relay contact voltage < 2V | 1sec | OFF | OFF | ON | Power "OFF" | ● Pre-charge circuit error |
17.5V > Fail safe relay contact voltage > 9V | Booster voltage < Fail safe relay contact voltage | 2sec | OFF | ON | ON | Booster V ≥ relay contact V | ● Booster circuit error |
System power "ON" | Motor terminal > 23V or < -3V | 0.2sec | OFF | OFF | ON | Power "OFF" | ● Motor terminal V motor I/F error |
Fail safe relay contact voltage > 8V | Interlock circuit locked permit | 0.2sec | OFF | OFF | ON | Power "OFF" | ● Interlock circuit error |
Fail safe relay contact voltage > 7.5V | [Torpue sensor main I/F input -output] > 2.5Nm | 0.2sec | OFF | ON | OFF | Power "OFF" | ● Torque sensor main I/F error |
System power "ON" | Detected temperature < -40℃ | 0.2sec | Control 60℃ | ON | OFF | Power "OFF" | ● Thermis-tor error |
System power "ON" | EEPROM read error | Instantly | Initial value control | ON | OFF | Power "OFF" | ●EEPROM |
