Based on information from various sensors, the ECM measures the fuel injection amount. The fuel injector is a solenoid-operated valve and the fuel injection amount is controlled by length of time the fuel injector is held open. The ECM controls each injector by grounding the control circuit. When the ECM energizes the injector by grounding the control circuit, the circuit voltage should be low (theoretically 0V) and the fuel is injected. When the ECM de-energizes the injector by opening the control circuit, the fuel injector is closed and circuit voltage should momentarily peak.
Checking output signals from injectors. Under detecting condition, if an output signal is low, ECM sets P0273. MIL(Malfunction Indication Lamp) turns on when the malfunction lasts till consecutive 2 driving cycle.
Item | Detecting Condition | Possible Cause |
DTC Strategy |
•
Signal Low | 1. Poor connection 2. Open or short to ground in power harness 3. Open or short to ground in control harness 4. Injector 5. ECM |
Enable Conditions |
•
Engine running state
•
11V ≤ Battery voltage ≤ 16V
•
Above conditions are met > 0.5sec. | |
Threshold value |
•
Open or short to ground | |
Diagnosis Time |
•
Continuous (more than 5 sec. failure for every 10 sec.test) | |
MIL On Condition |
•
2 Driving Cycles |
Item | Coil resistance(Ω) |
Injector | 11.4 ~ 12.6Ω ( at 20℃/ 68℉) |
Fig.1) Normal waveforms of Injector under idle condition.
Fig.2) Normal data of Injector at idle.
Fig.3) Abnormal data of Injector when cylinder 2 injector has an open circuit.
When the ECM energizes the injector by grounding control circuit, the circuit voltage should be low (theoretically 0V) and the fuel is injected. When the ECM de-energizes the injector by opening control circuit, the fuel injector is closed and circuit voltage should be peak at a moment.
