AQS(Air Quality System)
keeps air inside in the most suitable state for driver. In polluted area
AQS detects hazardous gas and intercepts inflow automatically, Inversely,
In fresh area it allows the inflow of air to prevent the shortage of air
and the accumulation of carbon dioxide. AQS sensor is located at front
side of condensor and once hazardous gas is detected, it delivers the
voltage signal to ECU for closing intake door.
The ECM sets DTC B1258
if there is an open circuit in AQS sensor signal harness or the measured
voltage value of the sensor is more than the threshold value
Item
|
Detecting
Condition
|
Possible Cause
|
DTC
Strategy
|
|
| •
|
Short circuit in
harness |
|
Threshold
value
|
|
Detecting
time
|
|
FAIL
SAFE
|
| •
|
Intake door : return to previous
state. | |
※ Voltage value of AQS
sensor as a function of position of operating condition.
Operating
condition
|
Voltage
|
Note
|
Right
after IGN "ON"
|
2.5V ±
0.3V
|
preheating(35 ± 2sec)
|
normal
|
4.3V ±
0.3V
|
Intake
door : FRE
|
Gas
detected
|
0.9V ±
0.3V
|
Intake
door : REC
|
| 1. |
Connect scantool to Data Link
Connector(DLC). |
| 2. |
Warm up the engine to normal operating
temperature. |
| 3. |
Monitor DTC(Diagnostics Trouble Code) on the
scantool.
|
| 4. |
Is the same DTC displayed again?
|
|
▶ Go to "
Inspection/Repair " procedure .
|
|
|
▶ Fault is
intermittent caused by poor contact in the sensor's and/or
A/C-ECM connector or was repaired and A/C-ECM memory was not
cleared. Thoroughly check connectors for looseness,
poorconnection, bending, corrosion, contamination,
deterioration, or damage. Repair or replace as necessary and
go to "Verification of vehicle Repair"
procedure.
|
|
| 1. |
Many malfunctions in the electrical system are
caused by poor harness and terminals. 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 go to "Verification of Vehicle Repair"
procedure
|
|
|
▶ Go to
"Signal circuit Short Inspection"
procedure.
|
|
| Signal Circuit Short
Inspection |
| 2. |
A/C-ECU : Connect, AQS sensor :
Disconnect. |
| 3. |
Measure resistance between Signal(+) terminal
of AQS sensor harness connector and and chassis ground
.
|
| 4. |
Is "resistance" display near the specified
value?
|
|
▶ Go to "
Component inspection " procedure .
|
|
|
▶ Check for
short in harness.
▶ Repair as
necessary and then go to "Verification of Vehicle Repair"
procedure.
|
|
| 2. |
A/C-ECU, AQS sensor :
Connect. |
| 3. |
Ignition "ON"(ENGINE
"OFF"). |
| 4. |
Measure voltage between Signal(F/B) terminal
of AQS sensor harness connector and and chassis ground .(Component
side)
Specification
: Refer the specifications in
fig.1
|
Operating
condition
|
Voltage
|
Note
|
Right after IGN "ON"
|
2.5V ± 0.3V
|
preheating(35 ± 2sec)
|
normal
|
4.3V ± 0.3V
|
Intake door : FRE
|
Gas
detected
|
0.9V ± 0.3V
|
Intake door :
REC
|
※ Voltage value of AQS sensor as a function of
position of operating condition. |
| 5. |
Is "voltage" display near the specified
value?
|
|
▶ 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.
|
|
|
▶
Substitute with a known-good AQS sensor and check for proper
operation. If the problem is corrected, replace AQS sensor and
then go to "Verification of Vehicle Repair"
procedure.
|
|
| Verification Of Vehicle
Repair |
After a repair, it is
essential to verifying that the fault has been corrected.
| 1. |
Connect scan tool and select "Diagnostic
Trouble Codes(DTCs)" mode. |
| 2. |
Using scantool, Clear
DTC. |
| 3. |
Operate the vehicle within DTC Enable
conditions in General information. |
| 4. |
Are any DTCs present?
|
|
▶ Go to the
applicable troubleshooting procedure.
|
|
|
▶ System is
performing to specification at this
time.
|
|
