P3954 Mercedes-benz 770 OBD Code

OBD/2 P3954 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.

As long as the throttle plate remains closed, the idling speed and quality is controlled by the PCM via the idle control valve, and as can be seen from the above it should be clear that idle control on a gasoline engine is a complex affair. For instance, if the engine is started in sub-zero temperatures, the PCM will command the idling control valve to allow less air to enter the engine to enrich the air/fuel mixture to create a condition which is roughly analogous to how chokes worked on carburetted engines to control idling in cold weather.

P3954 Mercedes-benz 770 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.

Difficulty Level (Easy)
Level
Repair Time (20 Min.)
Time
Cost Prediction : $ 60-110

Common Causes of Mercedes-benz 770 P3954 OBD2 Code

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 ;
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.

P3954 code for other Mercedes-benz cars

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

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

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