Diagnostic Trouble Code (Dtc) P0203 Injector Circuit Malfunction - Cylinder - Isuzu 1999 RODEO Workshop Manual

6E1–182 RODEO X22SE 2.2L ENGINE DRIVEABILITY AND EMISSION
DIAGNOSTIC TROUBLE CODE (DTC) P0202 INJECTOR CIRCUIT
Circuit Description
The powertrain control module (PCM) has four individual
injector driver circuits. Each controls an injector. When a
driver circuit is grounded by the PCM, the injector is
activated. The PCM monitors the current in each driver
circuit. The PCM 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
PCM expects to monitor on the circuit, a Diagnostic
Trouble Code is set. This Diagnostic Trouble Code is also
set if an injector driver is shorted to voltage. DTC P0202
is a type A code.
Conditions for Setting the DTC
f The battery voltage is greater than 9 volts.
f Engine is running.
f Fuel pump is ON.
f The injector voltage does not equal the ignition voltage
when the injector is commanded OFF or the injector
voltage does not equal 0 volts when the injector is
commanded ON.
f The above conditions are met for 5 seconds.
Action Taken When the DTC Sets
f The PCM will illuminate the malfunction indicator lamp
(MIL) the first time the fault is detected.
f "Open Loop" fuel control will be in effect.
MALFUNCTION – CYLINDER 2
f The PCM will store conditions which were present
when the Diagnostic Trouble Code was set as Freeze
Frame and in the Failure Records data.
Conditions for Clearing the MIL/DTC
f The PCM will turn OFF the MIL on the third consecutive
trip cycle in which the diagnostic has been run and the
fault is no longer present.
f A history Diagnostic Trouble Code P0202 will clear
after 40 consecutive warm–up cycles occur without a
fault.
f Diagnostic Trouble Code P0202 can be cleared by
using the Scan Tool's "Clear Info" function.
Diagnostic Aids
An injector driver circuit that is open or shorted to voltage
will cause a Diagnostic Trouble Code P0202 to set. It will
also cause a misfire due to an inoperative injector. A
misfire Diagnostic Trouble Code will also be set indicating
which cylinder is inoperative.
Long term and short term fuel trims that are excessively
high or low are a good indication that an injector is faulty.
Use Fuel Injector Coil Test Procedure to check for faulty
injectors.
Test Description
Number(s) below refer to the step number(s) on the
Diagnostic Chart:
D06RX049