P3840 Trouble Code

View P3840 obd/2 error code description and symptoms. P3840 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.

Difficulty Level (Expert)
Level
Repair Time (35 Min.)
Time
Cost Prediction : $ 50-100

P3840 Error Code Repair Process :

OBD P3840 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 contactor 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 P3840 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 P3840 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.

Wrench Tool P3840 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.

Common Causes of P3840

A common cause of code P3840 is the failure of Contactor Circuit Failure, but there are several other possible causes as well, such as ;

P3840 code for all cars

You can view according P3840 DTC for your car model. We selected several models to see obd2 solutions click and view it.

+P3840 Fiat Linea +P3840 Mercedes Cl 55 +P3840 Volkswagen Golf 6 +P3840 Nissan 211 +P3840 Honda Acura Cl

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

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