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 BUICK 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 Buick models: 2000-2008 Buick Century2000-2008 Buick LeSabre2000-2008 Buick Park Avenue2000-2008 Buick Regal2002-2008 Buick Rendezvous2000-2008 Buick

Possible causes – Faulty Oxygen sensor– Ignition problem– Fuel injection problem– Engine mechanical condition Tech notes There is a factory service bulletin for the following Buick models: 2000-2008 Buick Century2000-2008 Buick LeSabre2000-2008 Buick Park Avenue2000-2008 Buick Regal2002-2008 Buick Rendezvous2000-2008 Buick

Possible causes – Faulty Powertrain Control Modules (PCM)– Low car battery voltage When is the code detected? If the checksum of the Electronically Erasable Programmable Read Only Memory (EEPROM) does not match a predetermined value by the Powertrain Control Modules

Possible causes – Faulty Rear Heated Oxygen Sensor Bank 1– Rear Heated Oxygen Sensor Bank 1 harness is open or shorted– Rear Heated Oxygen Sensor Bank 1 circuit poor electrical connection– Intake air leaks– Exhaust gas leaks– Inappropriate fuel pressure–

Possible causes – Faulty Throttle Actuator Control (TAC) module– Throttle Actuator Control (TAC) module harness is open or shorted– Throttle Actuator Control (TAC) module circuit poor electrical connection (loose or broken wires) When is the code detected? The Throttle Actuator

Possible causes – Faulty Throttle Actuator Control (TAC) module– Throttle Actuator Control (TAC) module harness is open or shorted– Throttle Actuator Control (TAC) module circuit poor electrical connection– Check Throttle Actuator Control (TAC) module connector for water– Binding or bent

Possible causes – Faulty Throttle Actuator Control (TAC) module– Throttle Actuator Control (TAC) module harness is open or shorted– Throttle Actuator Control (TAC) module circuit poor electrical connection– Throttle plate sticking due to carbon build-up– Engine Control Module When is

Possible causes – Faulty Throttle Actuator Control (TAC) module– Throttle Actuator Control (TAC) module harness is open or shorted– Throttle Actuator Control (TAC) module circuit poor electrical connection– Throttle plate sticking due to carbon build-up– Engine Control Module When is

Possible causes – Faulty Throttle Actuator Control (TAC) module– Throttle Actuator Control (TAC) module harness is open or shorted– Throttle Actuator Control (TAC) module circuit poor electrical connection When is the code detected? The Engine Control Module (ECM) has detected

Possible causes – Faulty Throttle Position Sensor– Throttle Position Sensor harness is open or shorted– Throttle Position Sensor circuit poor electrical connection– Throttle Position Sensor not properly adjusted When is the code detected? When the Powertrain Control Module (PCM) senses

Possible causes – Faulty Throttle Position Sensor– Throttle Position Sensor harness is open or shorted– Throttle Position Sensor circuit poor electrical connection– Throttle Position Sensor not properly adjusted When is the code detected? When the Powertrain Control Module (PCM) senses