P0203 - CYLINDER 3 INJECTOR CIRCUIT MALFUNCTION

The fuel system has a set of injectors. These injectors have a solenoid, which is energized, also raises a valve inside the injector to distribute fuel in the engine. Generally, one of the two injector terminals has battery power. When an injection is requested, the PCM (Powertrain Control Module) controller connect to ground the other terminal. This supplies the injector circuit.

Diagnostic code P0203 OBDII is established when the PCM has detected a malfunction in fuel injector circuit number 3. This malfunction is due to the PCM ordering the injector to activate or deactivate, but not observing the corresponding change in voltage.

• The Engine Malfunction light (MIL) illuminates.
• Failure to turn on.
• The engine may not start.
• The engine may start, but stops.

The reasons why DTC code P0203 OBD2 is set are:

• Injector circuit short due to worn or corroded cables.
• Electrical connection in the deficient fuel injector.
• Fuel injector number 3 may be defective.

To solve the problems related to the fault code P0203 OBD II do the following:

• Using a Digital Volt-Ohmmeter check the resistance of the injector. Then, compare the results with the specifications. If it is not within specifications, you must change the injector.
• Check the voltage on the injector connector. They must be 10 volts minimum.
• Make sure there is no physical damage to the connector. Also check the cables, they may be defective, repair or replace as necessary.
• With an injector tester, you must activate the injector to test its operation. If you do not have access to an injector tester, change the position of the injector. If the code changes, the problem is the injector.
• Proceed to replace the fuel injector.