Possible causes – Faulty front heated oxygen sensor– Ignition misfiring– Faulty fuel injectors– Exhaust gas leaks– Incorrect fuel pressure – Faulty Mass Air Flow (MAF) sensor Tech notes There is a factory service bulletin for the following Oldsmobile models: 2000-2004

Possible causes – Faulty Heated Oxygen Sensor (H2OS) Bank 2 Sensor 1– Heated Oxygen Sensor (H2OS) Bank 2 Sensor 1 harness is open shorted– Heated Oxygen Sensor (H2OS) Bank 2 Sensor 1 circuit poor electrical connection– Heated Oxygen Sensor (H2OS)

Possible causes – Faulty Heated Oxygen Sensor (H2OS) Bank 2 Sensor 1– Heated Oxygen Sensor (H2OS) Bank 2 Sensor 1 harness is open shorted– Heated Oxygen Sensor (H2OS) Bank 2 Sensor 1 circuit poor electrical connection– Heated Oxygen Sensor (H2OS)

Possible causes – Faulty mass air flow sensor– Intake air leaks– Dirty mass air flow sensor– Dirty mass air filter– Mass air flow sensor harness is open or shorted– Mass air flow sensor circuit poor electrical connection Tech notes Before

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– Inappropriate fuel pressure– Faulty fuel injectors– Intake air leaks

Possible causes – Faulty spark plug (s) – Faulty ignition coil (s) – Clogged or faulty fuel injector (s)– Intake air leak– Fuel injectors harness is open or shorted– Fuel Injectors circuit poor electrical connection– Ignition coils harness is open

Possible causes – Faulty throttle position sensor.– Throttle position sensor harness is open or shorted– Throttle position sensor circuit poor electrical connection When is the code detected? An excessively low voltage from the Throttle Position Sensor (TPS) is sent to

Possible causes – Faulty Transmission Speed Sensor– Transmission Speed Sensor harness is open or shorted– Transmission Speed Sensor circuit poor electrical connection When is the code detected? Diagnostic Trouble Code (DTC) P0717 is detected when TCM or ECM receives no

Possible causes – Faulty Vacuum hoses damaged– Faulty Air Pump inoperative– Air bypass solenoid harness is open or shorted– Air bypass solenoid circuit poor electrical connection– Air bypass solenoid leaking/blocked or stuck open/closed– Air diverter valve leaking/blocked or stuck open/closed

Possible causes – Heated Oxygen Sensor (H2OS) Bank 2 Sensor 1 harness is open shorted to ground– Heated Oxygen Sensor (H2OS) Bank 2 Sensor 1 circuit poor electrical connection– Faulty Heated Oxygen Sensor (H2OS) Bank 2 Sensor 1– Heated Oxygen

Possible causes – Intake air leaks– Faulty front heated oxygen sensor– Ignition misfiring – Faulty fuel injectors – Exhaust gas leaks– Incorrect fuel pressure– Lack of fuel– Faulty Mass Air Flow (MAF) sensor– Incorrect Positive Crankcase Ventilation (PCV) hose connection

Possible causes – Intake air leaks– Faulty front heated oxygen sensor– Ignition misfiring– Faulty fuel injectors– Exhaust gas leaks– Incorrect fuel pressure– Lack of fuel– Faulty Mass Air Flow (MAF) sensor– Incorrect Positive Crankcase Ventilation (PCV) hose connection Tech notes

Possible causes – EVAP canister vent control solenoid harness is open or shorted – EVAP canister vent control solenoid circuit poor electrical connection – Faulty EVAP canister vent control solenoid Symptoms – Engine Light ON (or Service Engine Soon Warning

Possible causes – Faulty EVAP Purge Solenoid– EVAP Purge Solenoid harness is open or shorted– EVAP Purge Solenoid circuit poor electrical connection Symptoms – Engine Light ON (or Service Engine Soon Warning Light) P1655 OLDSMOBILE Description The Powertrain Control Module

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 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 Oxygen sensor– Ignition problem– Fuel injection problem– Engine mechanical condition Tech notes There is a factory service bulletin for the following Oldsmobile models: 2000-2004 Oldsmobile Alero2000-2005 Oldsmobile Silhouette2002-2004 Oldsmobile Bravada2000-2004 Oldsmobile Factory Service Bulletin OBDII Code

Possible causes – Faulty Oxygen sensor– Ignition problem– Fuel injection problem– Engine mechanical condition Tech notes There is a factory service bulletin for the following Oldsmobile models: 2000-2004 Oldsmobile Alero2000-2005 Oldsmobile Silhouette2002-2004 Oldsmobile Bravada2000-2004 Oldsmobile Factory Service Bulletin OBDII Code