Component Location
General Description
The ABS ECU(Electronic Control Unit) checks the battery voltage to determine, as a safety issue, whether the ABS system can operate normally or not. The normal battery voltage range is essential for controlling the ABS system as intended.
DTC Description
The ABS ECU monitors the battery voltage by reading the value of voltage. When the voltage is lower than the expected normal value, this code is set. The ABS function is prohibited and the EBD function is allowed on LOW VOLTAGE CONDITION, both the ABS and the EBD function are prohibited on UNDER VOLTAGE CONDITION. If the voltage recovers, to within normal operating ranges, then the controller returns to normal operations as well.
DTC Detecting Condition
Item | Detecting Condition | Possible cause |
DTC Strategy | ? Battery Voltage Monitoring | ? Poor connection in power supply circuit (IGN+) ? Faulty HECU |
Detect Mode | ? Initial Check ? Outside the ABS control cycle ? Inside the ABS control cycle ? Inside the EBD control cycle |
Case1 (Low voltage) | Enable Conditions | ? When VIGN<9V or VREF<9V continue 224ms, ECU detects the failure. - If voltage is recovered to normal operating voltage (VIGN >10V or VREF >10V), the system recovers to normal state. But in case of ABS control mode, all wheels inhibit until end of ABS control - VREF : Terminal voltage of REF line |
Fail Safe | ? Only the ABS functions are inhibited. ? The ABS warning lamps are activated and the EBD warning lamp is not activated. |
Case2 (Under voltage) | Enable Conditions | ? When VIGN<7.5V or VREF<7.5V continue 70ms, ECU detects the failure. - If voltage is recovered to normal operating voltage (VIGN >8.5V or VREF >8.5V), the system recovers to normal state. |
Fail Safe | ? Both the ABS and the EBD function are inhibited. ? The ABS and the EBD warning lamps are activated. |
Specification
Normal Operating Voltage Range | ENG "ON" |
9.5 V ~ 16.0 V |
Schematic Diagram