P0203

TROUBLESHOOTING PROCEDURES





CIRCUIT DIAGRAM











INSPECTION USING SCAN TOOL





HARNESS INSPECTION PROCEDURE

COMPONENT TEST PROCEDURE
Operation Check
Using a scan tool, check as described below.
- Cut off the fuel injectors in sequence.
- Check the operation time of the injectors.

Operation Sound Check





1. Using a stethoscope, check the injectors for a clicking sound at idle. Check that the sound is produced at shorter intervals as the engine speed increases.

NOTE: Ensure that the sound from an adjacent injector is not being transmitted along the delivery pipe to an inoperative injector.





2. If a stethoscope is not available, check the injector operation with your finger. If no vibrations are felt, check the wiring connector, injector, or injection signal from ECM.
Resistance Measurement Between Terminals
3. Disconnect the connector at the injector.





4. Measure the resistance between terminals.

Standard value: 13 - 16 Ohms at 20°C (68°F)

5. Connect the connector to the injector.

TROUBLESHOOTING HINTS
1. If the engine is hard to start when hot, check for fuel pressure and injector leaks.
2. If the injector does not operate when the engine is cranked, check for the following:
- Faulty power supply circuit to the ECM; faulty ground circuit
- Faulty control relay
- Faulty Crankshaft Position (CKP) Sensor, Camshaft Position (CMP) Sensor
3. If any cylinder's idle state remains unchanged when the fuel injection of each injector is cut one after another during idling, check the following:
- Injector and harness
- Ignition plug and high tension cable
- Compression pressure
4. If the injection system is OK, but the injector drive time is out of specification, check for the following:
- Injector and harness
- Poor combustion in the cylinder (faulty ignition plug, ignition coil, compression pressure, etc.)
- Loose EGR valve seating