P3954 Trouble Code

View P3954 obd/2 error code description and symptoms. P3954 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.

One example of this would be when an automatic vehicle in placed in gear. To prevent the added drag from the torque converter and transmission from reducing the idling speed, the PCM will command the idle control valve to allow more air to enter the engine, while at the same time, adjusting the injector pulse width to inject more fuel to suit the increased amount of air. Note that the idle air control valve is closed by the PCM when the throttle plate is opened to prevent excess air from entering the engine.

Difficulty Level (Expert)
Level
Repair Time (35 Min.)
Time
Cost Prediction : $ 60-110

P3954 Error Code Repair Process :

The rule of P3954 code when it comes to emissions-related vehicle repair is that any modification that changes the vehicle from a certified configuration to a non-certified configuration is considered tampering: this applies to both vehicle owners and repair facilities and is, therefore, a Federal offense. Replacing a catalyst with a straight pipe is one traditional example of scp (j1850) invalid or missing data for primary id. Likewise, overriding the OBD P3954 error in system through the use of high-tech defeat devices or non-certified computer chips, for example, would also be considered tampering. The OBD system may, however, be repaired back to its original certified configuration with certified performance chips or appropriate aftermarket parts.

Wrench Tool P3954 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 P3954

A common cause of code P3954 is the failure of SCP (J1850) Invalid or Missing Data for Primary Id, but there are several other possible causes as well, such as ;

P3954 code for all cars

You can view according P3954 DTC for your car model. We selected several models to see obd2 solutions click and view it.

+P3954 Mercedes Cl 600 +P3954 Jaguar E-type +P3954 Salmson 18 +P3954 Italdesign Legram +P3954 Mitsubishi Nessie

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