Daewoo CIELO EURO III Manual page 272

1F – 103 ENGINE CONTROLS
MANIFOLD ABSOLUTE PRESSURE (MAP) SENSOR HIGH VOLTAGE
Circuit Description
The engine control module (ECM) uses the
Manifold Absolute Pressure (MAP) sensor
to control the fuel delivery and the ignition
timing. The MAP sensor measures the changes in the
intake manifold pressure which results from engine load
(intake manifold vacuum) and the rpm changes; and
converts these into voltage outputs. The ECM
sends a 5 volt reference voltage to the MAP sensor. As
the manifold pressure changes, the output voltage of the
MAP sensor also changes. By monitoring the MAP sen-
sor output voltage, the ECM knows the manifold
pressure. A low pressure (low voltage) output voltage
will be about 1.0 to 1.5 volts at idle, while higher pres-
sure (high Voltage) output voltage will be about 4.5 to
4.8 at Wide Open Throttle (WOT). The MAP sensor is
also used, under certain conditions, to measure baro-
metric pressure, allowing the ECM to make adjust-
ments for different altitudes.
Conditions for Setting the DTC
No Throttle Position (TP) sensor fail conditions pres-
ent.
The Engine run time is greater than 10 seconds.
1.5L SOHC
The MAP is greater than 103 kPa.
The TP sensor is less than 20% if the rpm is less than
or equal to 3000.
The TP sensor is less than 30% if the rpm is greater
than 3000.
DIAGNOSTIC TROUBLE CODE (DTC) P0108
Action Taken When the DTC Sets
The Malfunction Indicator Lamp (MIL) will illuminate.
The ECM will record operating conditions at the
time the diagnostic fails. This information will be
stored in the Freeze Frame and Failure Records buff-
ers.
A history DTC is stored.
The ECM will substitute a fixed MAP value and
use Throttle Position (TP) to control the fuel delivery
(scan tool will not show defaulted value.)
Conditions for Clearing the MIL/DTC
The MIL will turn off after three (four –
1.5L SOHC) consecutive ignition cycles in which the
diagnostic runs without a fault.
A history DTC will clear after 40 consecutive warm up
cycles without a fault.
DTC(s) can be cleared by using the scan tool.
Diagnostic Aids
With the ignition ON and the engine stopped, the man-
ifold pressure is equal to atmospheric pressure, and the
signal voltage will be high.
This information is used by the ECM as an indica-
tion of vehicle altitude. Comparison of this reading with a
known good vehicle with the same sensor is a good way
to check the accuracy of a suspect sensor. Readings
should be the same r 0 .4 volt.
If a DTC P0108 is intermittent, refer to MAP Sensor Out-
put Check for further diagnosis.
DTC P0108 may set as a result of a misfire. If misfire is
present, repair the cause of misfire before using this
TAA1F140
DAEWOO T-154 BL2,3