Daewoo CIELO EURO III Manual page 514

1F – 344 ENGINE CONTROLS
Circuit Description
The A/C system uses an A/C refrigerant pressure sen-
sor mounted in the high pressure side of the A/C refrig-
erant system to monitor A/C refrigerant pressure. The
engine control module
(ECM) uses this information to turn ON the engine cool-
ant fans when the A/C refrigerant pressure is high and to
keep the compressor disengaged when A/C refrigerant
pressure is excessively high or low.
The Air Conditioning Pressure (ACP) sensor operates
like other 3-wire sensors. The ECM applies a
5.0 volt reference and a sensor ground to the sensor.
Changes in the A/C refrigerant pressure will cause the
ACP sensor input to the ECM to vary. The
ECM monitors the ACP sensor signal circuit and can de-
termine when the signal is outside of the possible range
of the sensor. When the signal is out of range for a pro-
longed period of time, the ECM will not allow the
A/C compressor clutch to engage. This is done to pro-
tect the compressor.
Conditions for Setting the DTC
1.5L SOHC
D Raw A/C pressure is greater than 99% of sensor
reading scale.
D Engine running.
Action Taken When the DTC Sets
D The Malfunction Indicator Lamp (MIL) will not illumi-
nate.
D The ECM will store conditions which were pres-
ent when the DTC set as Failure Records data only.
DIAGNOSTIC TROUBLE CODE (DTC) P0533
A/C PRESSURE SENSOR HIGH VOLTAGE
This information will not be stored as Freeze Frame
data.
D The A/C compressor operation will be disabled while
the low voltage indication exists.
Conditions for Clearing the MIL/DTC
D A history DTC will clear after 40 consecutive warm up
cycles without a fault.
D DTC(s) can be cleared by using the scan tool.
Diagnostic Aids
Inspect harness connectors for backed-out terminals,
improper mating, broken locks, improperly formed or
damaged terminals, and poor terminal-to-wire connec-
tion at the ECM.
Inspect the wiring harness for damage. If the harness
appears to be OK, observe the A/C pressure display on
the scan tool while moving the connectors and wiring
harnesses related to the ACP sensor. A change in the
A/C pressure display will indicate the location of the
fault.
If DTC P0533 cannot be duplicated, reviewing the Fail
Records vehicle mileage since the diagnostic test last
failed may help determine how often the condition that
caused the DTC to set occurs. This may assist in diag-
nosing the condition.
Test Description
Numbers below refer to the step numbers on the Diag-
nostic Table.
1. The On-Board Diagnostic (EOBD) System Check
prompts the technician to complete some basic
checks and store the freeze frame and failure re-
cords data on the scan tool if applicable. This
T/A1F340
DAEWOO T-154 BL2,3