Voltage - Daewoo MATIZ Service Manual

1F – 62 ENGINE CONTROLS
DIAGNOSTIC TROUBLE CODE (DTC) – P0108 MANIFOLD ABSOLUTE
Circuit Description
The engine control module (ECM) uses the Manifold Ab-
solute Pressure (MAP) sensor to control the fuel deliv-
ery and the ignition timing. The MAP sensor measures
the changes in the intake manifold pressure, which re-
sults 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 sensor 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
pressure (high voltage) output voltage will be about 4.5
to 4.8 at wide open throttle (WOT). The MAP sensor is
metric pressure, allowing the ECM to make adjustments
for different altitudes.
Conditions for Setting the DTC
D This DTC can be stored in "key-on" status.
D Engine speed is greater than 2,000rpm.
D No throttle position sensor (TPS) fail conditions pres-
ent.
D The MAP is greater than 600m bar.
D A high voltage condition exists.
Action Taken when the DTC Sets
D The Malfunction Indicator Lamp (MIL) will illuminate.
D The ECM will record operating conditions at the time
the diagnostic fails. This information will be stored in
the Freeze Frame and Failure Records buffers.
PRESSURE SENSOR HIGH VOLTAGE
D A history DTC is stored.
D The ECM will substitutes a fixed MAP value and use
TP to control the fuel delivery (the scan tool will not
show defaulted)
Conditions for Clearing the MIL/DTC
D The MIL will turn off after four consecutive ignition
cycles in which the diagnostic runs without a fault.
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
With the ignition ON and the engine stopped, the man-
ifold pressure is equal to atmosphere pressure and the
signal voltage will be high.
The ECM as an indication of vehicle altitude uses this
information. 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 ±0.4volt.
If a DTC P 0108 is intermittent, refer to "manifold abso-
lute pressure check" in this Section for further diagnosis.
If the connections are OK monitor the manifold absolute
pressure(MAP) sensor signal voltage while moving re-
lated connectors and the wiring harness. If the failure is
induced, the display on the scan tool will change. This
may help to isolate the location of an intermittent mal-
function.
MAA1F060
DAEWOO M-150 BL2