C3977 Trouble Code

View C3977 obd/2 error code description and symptoms. C3977 engine photo

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.

C3977 Error Code Repair Process :

When you turn on the ignition, the Service Engine Soon or Check Engine C3977 light should flash briefly, indicating that the OBD system is ready to scan your vehicle for any malfunctions. After this brief flash, the light should stay off while you drive as long as no problems are detected. If air suspension front inflator solenoid output circuit short to battery so, you'll be glad to know that your vehicle is equipped with an early warning system that could save you time, money, and fuel in addition to helping protect the air suspension front inflator solenoid output circuit short to battery.

C3977 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.

Common Causes of C3977

A common cause of code C3977 is the failure of Air Suspension Front Inflator Solenoid Output Circuit Short To Battery, but there are several other possible causes as well, such as ;

EVAP canister or fuel tank leaks
Engine Control Module (ECM)
Foreign matter caught in fuel filler cap
Faulty Fuel injector

C3977 code for all cars

You can view according C3977 DTC for your car model. We selected several models to see obd2 solutions click and view it.

+C3977 Mitsubishi Field Guard

+C3977 Chrysler Ccv

+C3977 Mazda Mazda 5

+C3977 Chevrolet Constantia

+C3977 Reliant Scimitar

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