C0991 Opel Astra H OBD Code

OBD/2 C0991 error code description and symptoms.

Low Speed Fuel Pump Primary Circuit Malfunction The PCM monitors the low speed fuel pump (LFP) primary circuit output from the PCM.
The test fails if: When the LFP circuit is commanded on (grounded), excessive current draw is detected on the LFP circuit; or when the LFP circuit is commanded off, voltage is not detected on the LFP circuit (the PCM expects to detect VPWR voltage coming through the low speed fuel pump relay coil to the LFP circuit). Open or shorted low fuel pump (LFP) circuit Open VPWR to low speed fuel pump relay Damaged low speed fuel pump relay Damaged PCM An open circuit or short to ground can only be detected with the low speed fuel pump.

Gear changes are accomplished by a command from the TCM to energize the clutch actuator to release the clutch; after which various actuators inside the transmission disengage the current gear, and depending on current operating conditions, engage the next higher or lower gear ratio. All of this happens much faster than a human driver could change gears, and in most applications, gear changes are as smooth and seamless as on any fully automatic transmission.

C0991 Opel Astra H Error Code Repair Process :

OBD C0991 code and tailpipe testing are two different approaches to identify vehicles in need of repair. The OBD system looks for broken or malfunctioning emissions control components and abs outlet valve coil rr circuit failure, while tailpipe tests sample a vehicle's exhaust to see if it is above or below certain prescribed limits. Given the robust nature of today's emissions control components, it is entirely possible for an individual component to C0991 malfunction without leading to an immediate increase in emissions at the tailpipe. In such cases, other components (like the catalyst) can temporarily compensate for the part that is broken however, these other components can only do double duty for so long before they, too, begin to malfunction. In addition, OBD also monitors for C0991 and other malfunctions in the fuel system problems that traditional tailpipe tests were not designed to identify. Most state and local areas also include a gas cap pressure test as part of an emission inspection.

Common Causes of Opel Astra H C0991 OBD2 Code

A common cause of code C0991 is the failure of ABS Outlet Valve Coil RR Circuit Failure, but there are several other possible causes as well, such as ;

EVAP canister or fuel tank leaks
Faulty Fuel injector
Intake Valve Timing Control Solenoid Valve circuit poor electrical connection
Faulty select solenoid

C0991 is a kind of Chassis Trouble Code

Diagnosing chassis noises can be one of the most frustrating problems technicians face. Fortunately, manufacturers have engineered noise, vibration and harshness (NVH) diagnostic techniques and equipment to find the source of the noise.

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

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C0991 Opel Astra H OBD Code

C0991 Opel Astra H Error Code Repair Process :

Common Causes of Opel Astra H C0991 OBD2 Code

C0991 code for other Opel cars