P0203

Circuit Description

This PCM contains a General Field Effect Transistor (FET) Driver (GFD) that controls the eight fuel injector drivers. The GFD contains circuitry that is used to determine if there is a problem with any of the fuel injector circuits. The GFD has a fault line for each injector. The fault line goes high when an open, short to ground, or short to voltage is noticed in an injector circuit. DTC P0203 is set when the fault line for injector # 3 is high.

Conditions for Running the DTC

^ DTCs P0560 and P1376 not set.
^ Ignition voltage between 10 and 16 volts.

Conditions for Setting the DTC

An injector circuit fault is detected for 0.5 second.

Action Taken When the DTC Sets

^ The faulty injector is disabled for the engine run cycle.
^ PCM disables Closed Loop operation.
^ The PCM will illuminate the Malfunction Indicator Lamp (MIL) when the diagnostic runs and fails.
^ The PCM will record operating conditions at the time the diagnostic fails. This information will be stored in the Freeze Frame and Failure Records.

Conditions for Clearing the MIL/DTC

^ The PCM will turn the MIL OFF after three consecutive drive trips that the diagnostic runs and does not fail.
^ A Last Test Failed (current) DTC will clear when the diagnostic runs and does not fail.
^ A History DTC will clear after forty consecutive warm-up cycles with no failures of any emission related diagnostic test.
^ Use a scan tool to clear DTCs.
^ Interrupting PCM battery voltage may or may not clear DTCs. This practice is not recommended.

Test Description

Number(s) below refer to the step number(s) on the Diagnostic Table.

2. If DTCs P0202, P0205 and P0208 are also set, power must be disabled to injectors 2, 3, 5 and 8.
3. If DTC P0203 is not current, drive vehicle until DTC resets. This will bring the injectors to the temperature at which the DTC set.
5. Checking to see if injector # 3 is receiving voltage. If not, the fault must be in the injector 2, 3, 5, 8 Ignition feed circuit between the splice and injector # 3.
7. Checking for a shorted injector. Resistance should be between 8 to 25 ohms.
9. Checking for poor terminal contact at PCM connector C2 terminal 12.
10. Checking for an open or short to ground in the injector 3 control circuit between PCM and fuel rail connector.
11. Checking for a short to ground in the injector 3 control circuit between fuel rail connector and injector # 3.
12. Checking for an open fuel injector. Resistance should be between 8 to 25 ohms.