P0206

Schematic:

CIRCUIT DESCRIPTION
The Engine Control Module (ECM) enables an injector on the intake stroke of each cylinder. Each individual cylinder fuel control is referred to as the Sequential Multiport Fuel Injection (SFI). Switched B+ voltage is supplied directly to the fuel injectors from the engine control power relay. The ECM controls each injector by grounding the control circuit via an internal switch called a driver. The primary function of the driver is to supply the ground for the component being controlled. Each driver has a fault line which is monitored by the ECM. When the ECM is commanding a component ON, the voltage of the control circuit should be low, near 0 volts. When the ECM is commanding the control circuit to a component OFF, the voltage potential of the circuit should be high, near battery voltage. If the fault detection circuit senses a voltage other than what is expected, this Diagnostic Trouble Code (DTC) will set.

The ECM will monitor the injector circuit for the following conditions:
^ Short to ground
^ Short to voltage
^ Open circuit
^ An internally shorted or excessively low resistance injector

When the ECM detects any of the above malfunctions, this DTC will set and the affected driver will be disabled. The ECM will continue to test the circuit and if the fault goes away, the driver will be reactivated.

CONDITIONS FOR RUNNING THE DTC
^ The ignition voltage is between 7.5-15 volts.
^ The engine speed is more than 40 RPM.

CONDITIONS FOR SETTING THE DTC
An injector circuit fault is detected.

ACTION TAKEN WHEN THE DTC SETS
The ECM illuminates the Malfunction Indicator Lamp (MIL) and records the operating conditions in the Freeze Frame on the second consecutive drive trip that the diagnostic runs and fails.

CONDITIONS FOR CLEARING THE MIL/DTC
^ The ECM turns OFF the MIL after three consecutive drive trips that the diagnostic runs and passes.
^ A History DTC clears after forty consecutive warm-up cycles in which no failures are reported by this diagnostic or any other emission related diagnostic.
^ The scan tool clears the MIL/DTC.

DIAGNOSTIC AIDS
Use the J 35616-A connector test adapter kit for any test that requires probing the ECM harness connector or a component harness connector.

Check for the following conditions:
^ Poor connections at the ECM or at the component-Inspect the harness connectors for any backed out terminals, improper mating, broken locks, improperly formed or damaged terminals, and poor terminal to wire connection. Refer to Testing for Intermittent and Poor Connections in diagrams for the proper procedure.
^ Damaged harness-Inspect the wiring harness for any damage. If the harness appears to be OK, observe the scan tool while moving the related connectors and the wiring harnesses. A change in the display may help in order to locate the fault.

Refer to Testing for Intermittent and Poor Connections in diagrams for the Intermittents.

TEST DESCRIPTION

Steps 1 - 8:

Steps 9 - 18:

The numbers below refer to the step numbers on the diagnostic table.
3. This step is to test the control circuit for a short to voltage.
6. This step is to isolate the fault to the control circuit or the ECM.
8. At this point, the fault is isolated to the engine side of the harness. This step will determine the type of fault. The upper intake will require removal in order to complete the diagnosis.