P0200

CIRCUIT DESCRIPTION
The PCM enables an injector on the intake stroke of each cylinder. Individual cylinder fuel control is referred to as Sequential Multi-port Fuel Injection (SFI). Ignition voltage is supplied directly to the fuel injectors. The PCM 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 or control circuit is equipped with a fault line which is monitored by the PCM. When the PCM is commanding an injector ON, the voltage of the control circuit should be low. When the PCM is commanding the injector OFF, the voltage potential of the control circuit should be high. If the PCM detects the injector control circuit voltage other than what is expected, the PCM sets a DTC.

CONDITIONS FOR RUNNING THE DTC
^ The engine speed is more than 400 RPM.
^ The ignition voltage is more than 6.0 volts but less than 18.0 volts.

CONDITIONS FOR SETTING THE DTC
The PCM detects the wrong voltage potential on any injector driver circuit for 5 seconds.

ACTION TAKEN WHEN THE DTC SETS
^ The PCM illuminates the Malfunction Indicator Lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
^ The PCM records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the PCM stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the PCM records the operating conditions at the time of the failure. The PCM writes the conditions to the Freeze Frame and updates the Failure Records.

CONDITIONS FOR CLEARING THE MIL/DTC
^ The PCM turns the Malfunction Indicator Lamp (MIL) OFF after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
^ A last test failed (current DTC) clears when the diagnostic runs and does not fail.
^ A History DTC clears after 40 consecutive warm-up cycles, if this or any other emission related diagnostic does not report any failures.
^ Use a scan tool in order to clear the MIL/DTC.

DIAGNOSTIC AIDS

IMPORTANT:
^ Remove any debris from the PCM connector surfaces before servicing the PCM. Inspect the PCM connector gaskets when diagnosing/replacing the PCM. Ensure that the gaskets are installed correctly. The gaskets prevent contaminant intrusion into the PCM.
^ For any test that requires probing the PCM or component harness connectors, use the J 35616-A connector test adapter kit. Using this kit prevents any damage to the harness connector terminals. Refer to Using Connector Test Adapters in Diagrams.

A misfire may not be apparent at idle. The misfire may only occur above idle under a load. Road test the vehicle and monitor the misfire current counters.

Observe, if more than one cylinder is mis-firing, the scan tool may only display one cylinder mis-firing. This will not be apparent until the repair is completed. Also, if an injector fuse is open for one side of the engine, the scan tool may only display 2 or 3 cylinders mis-firing.

When the injector driver is disabled, an engine misfire will be apparent and a misfire DTC sets.

For an intermittent condition, refer to Symptoms. Symptom Related Diagnostic Procedures

TEST DESCRIPTION

Steps 1 - 10:

Steps 11 - 20:

The numbers below refer to step numbers on the diagnostic table.
2. This step determines if a malfunction is present.
The Misfire Current Counters will not increment if certain DTCs set at the same time or after DTC P0300 sets. Refer to conditions for running DTC P0300 for applicable DTC list.
If more than one cylinder is misfiring, the Misfire Current Counters may increment for only one cylinder. Example: Cylinders 1 and 8 are both misfiring, yet only cylinder 8 increments on the Misfire Current Counter.
If one injector fuse open, only two or three Misfire current counters may increment for the corresponding side of the engine.
3. There are two ways to isolate a malfunctioning injector circuit:
^ DTC P0300 indicates a misfire is present. So use the Misfire Current Counters to locate the cylinder that is misfiring.
^ If no misfire DTC is present, Start and idle the engine while monitoring Misfire Current Counters. If a misfire is present, the Misfire Current Counters will increase for a cylinder that has a misfire.
4. The injector fuses also feed the ignition coil/modules. Thoroughly inspect the circuits going to the ignition coil/modules for a short to ground. A shorted ignition coil/module may also cause a fuse to open.
7. Inspect the injector connections before replacing the injector. A faulty connection causes an inoperative injector.
11. Disconnecting the PCM allows testing the continuity of the circuits with the DMM. This aids in locating an open or shorted circuit. Tests for an ignition feed circuit that is shorted to ground.
13. Tests for an ignition feed circuit that is shorted to ground.
14. The injector fuses also feed the ignition coil/modules. Thoroughly inspect the circuits going to the ignition coil/modules for a short to ground. A shorted ignition coil/module may also cause a fuse to open.