Possible causes – Faulty Heated Oxygen Sensor (HO2S) Bank 1 Sensor 1– Vacuum leak– Faulty Heated Oxygen Sensor (HO2S) Bank 1 Sensor 1 harness is open or shorted– Faulty Heated Oxygen Sensor (HO2S) Bank 1 Sensor 1 circuit poor electrical

Possible causes – Faulty Heated Oxygen Sensor (HO2S) Bank 2 Sensor 1– Heated Oxygen Sensor (HO2S) Bank 2 Sensor 1 harness is open or shorted– Heated Oxygen Sensor (HO2S) Bank 2 Sensor 1 circuit poor electrical connection When is the

Possible causes – Faulty Heated Oxygen Sensor Bank 1 or 2– Heated Oxygen Sensor Bank 1 or 2 harness is open or shorted– Heated Oxygen Sensor Bank 1 or 2 circuit poor electrical connection Symptoms – Engine Light ON (or

Possible causes – Faulty HO2S Bank 1 Sensor 1– HO2S Bank 1 Sensor 1 harness is open or shorted– HO2S Bank 1 Sensor 1 circuit poor electrical connection When is the code detected? The P1134 is sets if the Powertrain

Possible causes – Faulty HO2S Bank 1 Sensor 2– HO2S Bank 1 Sensor 2 harness is open or shorted– HO2S Bank 1 Sensor 2 circuit poor electrical connection Symptoms – Engine Light ON (or Service Engine Soon Warning Light)

Possible causes – Faulty HO2S Bank 1 Sensor 2– HO2S Bank 1 Sensor 2 harness is open or shorted– HO2S Bank 1 Sensor 2 circuit poor electrical connection Symptoms – Engine Light ON (or Service Engine Soon Warning Light)

Possible causes – Faulty HO2S Bank 1 Sensor 2– HO2S Bank 1 Sensor 2 harness is open or shorted– HO2S Bank 1 Sensor 2 circuit poor electrical connection Symptoms – Engine Light ON (or Service Engine Soon Warning Light)

Possible causes – Faulty HO2S Bank 1 Sensor 2– HO2S Bank 1 Sensor 2 harness is open or shorted– HO2S Bank 1 Sensor 2 circuit poor electrical connection Symptoms – Engine Light ON (or Service Engine Soon Warning Light)

Possible causes – Faulty HO2S Bank 1 Sensor 2– HO2S Bank 1 Sensor 2 harness is open or shorted– HO2S Bank 1 Sensor 2 circuit poor electrical connection Symptoms – Engine Light ON (or Service Engine Soon Warning Light)

Possible causes – Faulty Ignition Switch– Ignition Switch harness is open or shorted– Ignition Switch circuit poor electrical connection Symptoms – Engine Light ON (or Service Engine Soon Warning Light)

Possible causes – Faulty ignition switch– Ignition Switch harness is open or shorted– Ignition Switch circuit poor electrical connection– Faulty Engine Control Module (ECM) When is the code detected? The ECM has detected a voltage deifference between two circuits Symptoms

Possible causes – Faulty Intake Air Temperature Sensor– Intake Air Temperature Sensor harness is open or shorted– Intake Air Temperature Sensor circuit poor electrical connection When is the code detected? The P1111 code is set when the Powertrain Control Module

Possible causes – Faulty Intake Air Temperature Sensor– Intake Air Temperature Sensor harness is open or shorted– Intake Air Temperature Sensor circuit poor electrical connection Symptoms – Engine Light ON (or Service Engine Soon Warning Light) P1112 GMC Description The

Possible causes – Faulty Intake Camshaft Position sensor– Faulty Camshaft Position Solenoid Valve– Engine mechanical condition – Valve timing off– Intake Camshaft Position sensor harness is open or shorted– Intake Camshaft Position sensor circuit poor electrical connection When is the

Possible causes – Faulty Manifold Absolute Pressure (MAP) sensor– Manifold Absolute Pressure (MAP) sensor harness is open or shorted– Manifold Absolute Pressure (MAP) sensor circuit poor electrical connection When is the code detected? If the Powertrain Control Module (PCM) detects

Possible causes – Faulty Manifold Absolute Pressure (MAP) sensor– Manifold Absolute Pressure (MAP) sensor harness is open or shorted– Manifold Absolute Pressure (MAP) sensor circuit poor electrical connection When is the code detected? If the Powertrain Control Module (PCM) detects

Possible causes – Faulty Manifold Absolute Pressure (MAP) sensor– Manifold Absolute Pressure (MAP) sensor harness is open or shorted– Manifold Absolute Pressure (MAP) sensor circuit poor electrical connection When is the code detected? If the Powertrain Control Module (PCM) detects

Possible causes – Faulty Oxygen Sensor Bank 1– Oxygen Sensor Bank 1 harness is open or shorted– Oxygen Sensor Bank 1 circuit poor electrical connection Symptoms – Engine Light ON (or Service Engine Soon Warning Light)

Possible causes – Faulty Oxygen sensor– Ignition problem– Fuel injection problem– Engine mechanical condition Tech notes There is a factory service bulletin for the following GMC models: 2000-2008 GMC Sonoma2000-2008 GMC Sierra2000-2008 GMC Yukon2000-2008 GMC Yukon XL2001-2008 GMC Denali2001-2008 GMC

Possible causes – Faulty Oxygen sensor– Ignition problem– Fuel injection problem– Engine mechanical condition Tech notes There is a factory service bulletin for the following GMC models: 2000-2008 GMC Sonoma2000-2008 GMC Sierra2000-2008 GMC Yukon2000-2008 GMC Yukon XL2001-2008 GMC Denali2001-2008 GMC