Daewoo MATIZ Service Manual page 230

1F – 132 ENGINE CONTROLS
DIAGNOSTIC TROUBLE CODE (DTC) – P0268 INJECTOR 3 HIGH VOLTAGE
Circuit Description
The engine control module (ECM) has three individual
injector driver circuits, each of which controls an injector.
When a driver circuit is grounded by the ECM, the injec-
tor is activated. The ECM monitors the current in each
driver circuit. The ECM measures a voltage drop
through a fixed resistor and controls it. The voltage on
each driver is monitored to detect a fault. If the voltage is
not what the ECM expects to monitor on the circuit, a
Diagnostic Trouble Code (DTC) is set. This DTC detects
a low voltage and/or an open circuit and high voltage
conditions for low-side drive injector outputs.
Conditions for Setting the DTC
D This DTC can be stored in "key-on" status.
D The injector voltage does not equal the ignition volt-
age when the injector is commanded OFF, or the in-
jector voltage does not equal 0 volts when the injector
is commanded ON.
D The battery voltage is more than 16 volts.
D The above conditions are met for 5 seconds.
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 Records buffers.
D A history DTC is stored.
Conditions for Clearing the MIL/DTC
D The MIL will turn off after 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.
D Disconnecting the ECM battery feed for 10 seconds.
DIAGNOSTIC AIDS
An injector 4river circuit that is open or shorted to volt-
age will causes a DTC P0268 to set. It will also cause a
misfire due to an inoperative injector. A misfire DTC
should also be set indicating which injector is inopera-
tive.
Long-term and short-terms fuel trims that are excessive-
ly high or low are a good indication that an injector is
malfunctioning. Refer to "Fuel Injector 3alance Test" in
this Section to check for malfunctioning injectors.
MAA1F150
DAEWOO M-150 BL2