Daewoo CIELO EURO III Manual page 369

Circuit Description
The engine control
module (ECM) has four individual injector driver circuits,
each of which controls an injector. When a driver circuit
is grounded by the ECM, the injector is activated.
The ECM monitors the current in each driver cir-
cuit. 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 Diag-
nostic Trouble Code (DTC) is set. This DTC detects a
short to ground and/or an open circuit and short to bat-
tery conditions for low-side drive injector outputs.
Conditions for Setting the DTC
Engine is in run mode.
Engine speed is greater than 700 rpm (
1.5L SOHC).
The battery voltage is more than 9 volts.
The above conditions are met for 5 seconds.
Action Taken When the DTC Sets
The ECM will illuminate the Malfunction Indica-
tor Lamp (MIL) the first time the fault is detected.
The ECM will store conditions which were pres-
ent when the DTC was set as Freeze Frame and in
the Failure Records data.
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 within the freeze frame
conditions that the DTC failed.
A history DTC will clear after 40 consecutive warm up
cycles without a fault.
The DTC(s) can be cleared by using the scan tool.
DAEWOO T-154 BL2,3
DIAGNOSTIC TROUBLE CODE (DTC) P0201
INJECTOR 1 OUTPUT CIRCUIT FAULT
ENGINE CONTROLS 1F – 200
Diagnostic Aids
An injector driver circuit that is open or shorted to volt-
age will cause a DTC P0201 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-term fuel trims that are excessively
high or low are a good indication that an injector is mal-
functioning. Refer to "Fuel Injector Balance Test" in this
section to check for malfunctioning injectors.
The injector resistance tested at the ECM connec-
tion is slightly more than if tested directly at the injector
because it includes resistance of the harness wires. The
normal value is about 13.5 : .
Test Description
Number(s) below refer to the step number(s) on the
Diagnostic 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
creates an electronic copy of the data taken when
the malfunction occurred. The information is then
stored on the scan tool for later reference.
3. This step determines if DTC P0201 is the result of a
hard failure or an intermittent condition.
5. This step tests the wiring harness and the
ECM control of the injectors using a test light.
7. This step determines if the circuitry is shorted to volt-
age or if the ECM is faulty.
9. The replacement ECM must be repro-
grammed. Refer to the latest Techline procedure for
ECM reprogramming.