Based on information from various sensors, the PCM 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 PCM controls each injector by grounding the control circuit. When the PCM energizes the injector by grounding the control circuit, the circuit voltage should be low (theoretically 0V) and the fuel is injected. When the PCM 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. PCM sets P0276. MIL(Malfunction Indication Lamp) turns on when the malfunction lasts till consecutive 2 driving cycle.
Item
Detecting Condition
Possible Cause
DTC Strategy
? Signal Low
? Poor connection
? Open or short to ground in power harness
? Open or short to ground in control harness
? Injector
? PCM
Enable condition
? Engine running state
? 11V = Battery voltage = 16V
? Above conditions are met > 0.5sec.
? No disabling faults present
Threshold value
? Open or short to ground
Diagnosis time
? Continuous
MIL ON condition
? 2 driving cycles
Coil resistance(?)
Injector
11.4 ~ 12.6? ( at 20°C/ 68°F)
When the PCM energizes the injector by grounding control circuit, the circuit voltage should be low (theoretically 0V) and the fuel is injected. When the PCM de-energizes the injector by opening control circuit, the fuel injector is closed and circuit voltage should be peak at a moment.