P1991 Oldsmobile Ninety-eight OBD Code

OBD/2 P1991 error code description and symptoms.

The Camshaft Position sensor will signal the Engine Control Module when the #1 cylinder is ready for the spark plug to fire (top-dead-center on compression stroke). The ECM uses the information from this sensor to help calculate fuel delivery and spark timing.

Circuit High Input codes like P1991 are mostly caused by defective alternators that develop excessive voltages, although there may be other causes as well, such as short circuits that 'leak' current into a particular system from other, unrelated systems that work on higher voltages. Note that in the case of short circuits that leak power into a control circuit, there is likely to be other, seemingly unrelated trouble codes present along with the code(s) being investigated. Diagnosing a 'high input' code will always involve a thorough testing of the charging system as a first step, followed by measures to isolate the system from all other possible sources of power during resistance, continuity, and reference voltage tests.

P1991 Oldsmobile Ninety-eight Error Code Repair Process :

If your secondary air injection system switching valve a circuit malfunction check engine light is illuminated, it's best to take it in for diagnostic testing, which can feel like a hassle. Because while the lights vary in appearance from vehicle to vehicle, all have the same basic meaning: There's a problem with the car's emissions system. The on-board diagnostics system P1991 and engine control unit are in charge of monitoring a bunch of different secondary air injection system switching valve a circuit malfunction, and if they get a reading that's a little out of whack, up pops the check engine light.

Common Causes of Oldsmobile Ninety-eight P1991 OBD2 Code

A common cause of code P1991 is the failure of Secondary Air Injection System Switching Valve A Circuit Malfunction, but there are several other possible causes as well, such as ;

Clogged or faulty fuel injector (s)
Continuous oil flow to the VCT piston chamber
Fuel Injectors circuit poor electrical connection
Engine Control Module (ECM)

P1991 is a kind of Powertrain Trouble Code

Powertrain of a modern automobile, comprising engine (with exhaust system), transmission, drive shaft, suspension and the wheels. In a motor vehicle, the term powertrain or powerplant describes the main components that generate power and deliver it to the road surface, water, or air.

Engine OBD 2 Codes website is a freeware resource center for engine trouble codes.

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P1991 Oldsmobile Ninety-eight OBD Code

P1991 Oldsmobile Ninety-eight Error Code Repair Process :

Common Causes of Oldsmobile Ninety-eight P1991 OBD2 Code

P1991 code for other Oldsmobile cars