The ABS ECU(Electronic
Control Unit) checks the battery voltage and generator output 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.
The ABS ECU monitors the
battery voltage and generator output voltage by reading the value of
voltage.
When the voltage is
lower than the expected normal value, this code is set.
The ABS/ESC functions
are prohibited and the EBD function is allowed on LOW VOLTAGE CONDITION,
the ABS/EBD/ESC functions are prohibited on UNDER VOLTAGE
CONDITION.
If the voltage recovers,
to within normal operating ranges, then the controller returns to normal
operations as well.
Item
|
Detecting
condition
|
Possible cause
|
DTC
Strategy
|
| •
|
Battery Voltage
Monitoring | |
| •
|
Poor connection in power supply circuit
(IGN+) |
| •
|
Discharge of
electricity | |
Case1
(Low
voltage)
|
Enable
Conditions
|
| •
|
When Vign<9.5V±0.5V is continued for
500msec during Vref >=
7Km/h. |
| •
|
When Vign<8.5V±0.5V is continued for
500msec during Vref < 7Km/h or ABS/ESC
control.
- If IGN voltage is recovered to normal
operating voltage, the system recovers to normal
state. | |
Fail
Safe
|
| •
|
Inhibit the ABS/ESC control, allow the
EBD control , The ABS/ESC warning lamps are activated, When
the voltage recovers the normal operating range, erase the
error code. |
| •
|
Inhibit the ABS/ESC control. The ABS/ESC
warning lamps are activated. Althought the voltage recovers
the normal operating range, warning lamps are illuminated and
the error code is always
stored. | |
Case2
(Under
voltage)
|
Enable
Conditions
|
| •
|
When Vign<7.2V±0.5V is continued for
56msec.
- If IGN voltage is recovered to normal
operating voltage, the system recovers to normal
state. | |
Fail
Safe
|
| •
|
The ABS/EBD/ESC functions are
inhibited. |
| •
|
The ABS/EBD/ESC warning lamps are
activated. | |
Normal Voltage Range
|
ENG
"ON"
|
10V ~
16V
|
| 1. |
Connect scantool to Data Link
Connector(DLC). |
| 2. |
Ignition "ON" & Engine
"ON". |
| 3. |
Monitor the "BATTERY VOLTAGE" parameter on the
scantool.
Specification
: Above. 9±0.5V
|
|
| 4. |
Is parameter displayed within
specifications?
|
|
▶ Fault is
intermittent caused by poor connection in power harness (IGN+)
and/or HECU's connector or was repaired and HECU memory was
not cleared.
Thoroughly check
connectors for looseness, poor connection, bending, corrosion,
contamination, deterioration, or damage.
Repair or replace as necessary and then go to
"Verification Of Vehicle Repair" procedure.
|
|
|
▶ Go to
"Terminal and Connector Inspection"
procedure.
|
|
| Terminal and Connector
Inspection |
| 1. |
Many malfunctions in the electrical system are
caused by poor harness(es) and terminal condition. Faults can also
be caused by interference from other electrical systems, and
mechanical or chemical damage. |
| 2. |
Thoroughly check connectors for looseness,
poor connection, bending, corrosion, contamination, deterioration,
or damage. |
| 3. |
Has a problem been found?
|
|
▶ Repair as
necessary and then go to "Verification Of Vehicle Repair"
procedure.
|
|
|
▶ Go to
"Generator Output Voltage Inspection"
procedure.
|
|
Open or Short Check
| 1. |
Ignition "ON" & Engine
"OFF". |
| 2. |
Measure voltage between the battery
terminal(+) and power terminal of the HECU harness
connector.
Specification
: Approx. below
0.2V
| |
| 3. |
Is the measured value within
specifications?
|
|
▶ Go to
"Ground Circuit Inspection" procedure.
|
|
|
▶ Check for
open or blown 10A ABS fuse referring to "Circuit
Diagram".
Repair open or short in
power circuit between battery and HECU harness connector and
then go to "Verification Of Vehicle Repair"
procedure.
|
|
| Ground Circuit
Inspection |
Open or Short Check
| 1. |
Ignition "OFF" & Engine
"OFF". |
| 2. |
Disconnect HECU
connector. |
| 3. |
Measure resistance between ground terminal of
the HECU harness connector and chassis ground.
Specification
: Approx. below 1Ω
| |
| 4. |
Is the measured value within
specifications?
|
|
▶ Check for
open or blown 10A ABS fuse referring to "Circuit
Diagram".
|
|
|
▶ Repair
open or short in ground circuit between HECU harness connector
and chassis ground and then go to "Verification Of Vehicle
Repair"
procedure.
|
|
| Generator Output Voltage
Inspection |
Charging System Check
| 1. |
Ignition "ON" & Engine
"ON". |
| 2. |
Maintain ENG RPM 2,500RPM over 2
minutes. |
| 3. |
Measure voltage between the battery
terminal(+) and the battery terminal(-).
Specification
: Above. 9±0.5V
| |
| 4. |
Is the measured value within
specifications?
|
|
▶ Go to
"Power Circuit Inspection" procedure.
|
|
|
▶ Check
that the tension of drive belt, ENG RPM, fuse, terminal of
battery, all terminals of generator are in good condition and
Check for damaged harness and poor connection between
generator and battery.
If OK repair
or replace generator and then go to "Verification Of Vehicle
Repair"
procedure.
|
|
| Verification of Vehicle
Repair |
After a repair, it is
essential to verify that the fault has been corrected.
| 1. |
Connect scantool and select "Diagnostic
Trouble Codes(DTCs)" mode. |
| 2. |
Using a scantool, Clear
DTC. |
| 3. |
Operate the vehicle within DTC Detecting
Condition in General Information. |
| 4. |
Using a scantool, Check DTC
present. |
| 5. |
Are any DTCs present ?
|
|
▶ Go to the
applicable troubleshooting procedure.
|
|
|
▶ System
performing to specification at this
time.
|
|
