Possible causes – Faulty fuel composition sensor– Fuel Composition Sensor harness is open or shorted– Fuel Composition Sensor circuit poor electrical connection Tech notes Replaced Fuel Composition Sensor When is the code detected? The ECM detects that the fuel composition

Possible causes – Faulty fuel injector 1– Fuel Injector 1 harness is open or shorted– Fuel injector 1 circuit poor electrical connection When is the code detected? If an electrical malfunction occurs in the fuel injector circuit for engine cylinder

Possible causes – Faulty fuel injector 2– Fuel Injector 2 harness is open or shorted– Fuel injector 2 circuit poor electrical connection When is the code detected? If an electrical malfunction occurs in the fuel injector circuit for engine cylinder

Possible causes – Faulty fuel injector 3– Fuel Injector 3 harness is open or shorted– Fuel injector 3 circuit poor electrical connection When is the code detected? If an electrical malfunction occurs in the fuel injector circuit for engine cylinder

Possible causes – Faulty fuel injector 4– Fuel Injector 4 harness is open or shorted– Fuel injector 4 circuit poor electrical connection When is the code detected? If an electrical malfunction occurs in the fuel injector circuit for engine cylinder

Possible causes – Faulty fuel injector 5– Fuel Injector 5 harness is open or shorted– Fuel injector 5 circuit poor electrical connection When is the code detected? If an electrical malfunction occurs in the fuel injector circuit for engine cylinder

Possible causes – Faulty fuel injector 6– Fuel Injector 6 harness is open or shorted– Fuel injector 6 circuit poor electrical connection When is the code detected? If an electrical malfunction occurs in the fuel injector circuit for engine cylinder

Possible causes – Faulty fuel injector 7– Fuel Injector 7 harness is open or shorted– Fuel injector 7 circuit poor electrical connection When is the code detected? If an electrical malfunction occurs in the fuel injector circuit for engine cylinder

Possible causes – Faulty fuel injector 8– Fuel Injector 8 harness is open or shorted– Fuel injector 8 circuit poor electrical connection When is the code detected? If an electrical malfunction occurs in the fuel injector circuit for engine cylinder

Possible causes – Faulty fuel injector– Fuel Injector harness is open or shorted– Fuel injector circuit poor electrical connection When is the code detected? If the Powertrain Control Module (PCM) detects an incorrect voltage for the commanded state of the

Possible causes – Faulty Fuel Level Gauge– Fuel Level Gauge harness is open or shorted– Fuel Level Gauge circuit poor electrical connection– Faulty Powertrain Control Module (PCM) When is the code detected? If the fault detection circuit senses a voltage

Possible causes – Faulty fuel level sensor– Fuel level sensor harness is open or shorted– Fuel level sensor circuit poor electrical connection Tech notes Low fuel level can trigger this code. Before replacing any parts try filling up the fuel

Possible causes – Faulty fuel level sensor– Fuel level sensor harness is open or shorted– Fuel level sensor circuit poor electrical connection When is the code detected? An excessively high voltage is sent from the sensor is sent to Engine

Possible causes – Faulty fuel level sensor– Fuel level sensor harness is open or shorted– Fuel level sensor circuit poor electrical connection When is the code detected? The output signal of the fuel level sensor does not change within the

Possible causes – Faulty fuel pressure sensor– Fuel pressure sensor harness is open or shorted– Fuel pressure sensor electrical circuit poor connection– Faulty Engine Control Module (ECM) When is the code detected? If the current is outside of the expected

Possible causes – Faulty fuel pressure sensor– Fuel pressure sensor harness is open or shorted– Fuel pressure sensor electrical circuit poor connection– Faulty Engine Control Module (ECM) When is the code detected? If the fuel rail pressure sensor indicates a

Possible causes – Faulty Fuel Pump Relay– Fuel Pump Relay harness is open or shorted– Fuel Pump Relay circuit poor electrical connection– Faulty Powertrain Control Module (PCM) When is the code detected? The P0230 code will be set when the

Possible causes – Faulty fuel pump– Blocked fuel filter– Faulty fuel pressure sensor– Fuel pressure sensor harness is open or shorted– Fuel pressure sensor electrical circuit poor connection– Faulty Fuel injector Tech notes There is a factory service bulletin for

Possible causes – Faulty fuel pump– Blocked fuel filter– Faulty fuel pressure solenoid– Faulty Fuel injector Tech notes There is a factory service bulletin for the P0093 Code 2001-2004 GMC Sierra2003-2004 GMC Topkick C4500/C5500 SeriesGMC Factor Service Bulletin OBDII Code

Possible causes – Faulty Fuel Tank Pressure Sensor– Fuel Tank Pressure Sensor harness is open or shorted– Fuel Tank Pressure Sensor circuit poor electrical connection Tech notes On most GMC vehicles the sensor is on top of the fuel tank.