P0203

Diagnostic Chart (Part 1 Of 2):

Diagnostic Chart (Part 2 Of 2):

CIRCUIT DESCRIPTION
The Powertrain Control Module (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 is running.
^ The ignition voltage is more than 9.0 volts.

CONDITIONS FOR SETTING THE DTC
The PCM detects an injector current less than 4 amps for one second.

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 OFF the Malfunction Indicator Lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
^ A last test failed, or current DTC, clears when the diagnostic runs and does not fail.
^ A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
^ Use a scan tool in order to clear the MIL and the 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 water intrusion into the PCM.

^ The following may cause an intermittent:
- Poor connections-Check for adequate terminal tension. Refer to Testing for Intermittent and Poor Connections or to Connector Repairs in Diagrams.
- Corrosion
- Mis-routed harness
- Rubbed through wire insulation
- Broken wire inside the insulation
^ When the injector driver is disabled, an engine misfire will be apparent and a misfire DTC sets.
^ Using the Freeze Frame and/or Failure Records data may aid in locating an intermittent condition. If you cannot duplicate the DTC, the information included in the Freeze Frame and/or Failure Records data can help determine how many miles since the DTC set. The fail counter and pass counter can also help determine how many ignition cycles the diagnostic reported a pass and/or a fail. Operate the vehicle within the same Freeze Frame conditions RPM, load, vehicle speed. temperature etc.) that you observed This will isolate when the DTC tailed. For an intermittent condition, refer to Symptoms. Symptom Related Diagnostic Procedures