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U3857 Engine Code Repair

Meaning of U3857 engine trouble code is a kind of network trouble code and U3857 if your catalytic convertor fails completely, you eventually won't be able to keep the car running. Your gas mileage will also be terrible, so you should try and fix it as soon as you can. Unfortunately, the average replacement cost is around $2,140 and you can't do it yourself unless you're an experienced mechanic.

U3857 Fault Symptoms :

  1. Check engine light comes on
  2. Engine stalling or misfiring
  3. Engine performance issues
  4. Car not starting

If one of these reasons for U3857 code is occuring now you should check U3857 repair processes.
Now don't ask yourself; What should you do with U3857 code ?
The solution is here :

U3857 Possible Solution:

U3857 Engine

Air Conditioning Pressure Sensor (ACP) Insufficient Pressure Change Each time the A/C clutch engages, the PCM is looking for a pressure change in the refrigerant. If the change in pressure is outside of the calibration the DTC will set. A/C system mechanical failure Open ACP or VREF circuit A/C sensor damaged A/C system electrical failure A/C clutch always engaged Verify A/C system function, including refrigerant charge.

U3857 Code Meaning :

U
OBD-II Diagnostic Network (U) Trouble Code For Engine

3
Ignition System Or Misfire

8
Fuel Rail Pressure Sensor Circuit Malfunction

5
Injection lump Fuel Metering Control 'B' High (Cam/Rotor/Injector)

7
Ignition Coil A Primary/Secondary Circuit Malfunction

Is the fuel pump sometimes not priming when you turn the key to ON(II)? Start by measuring the fuel pressure and checking whether you have bright white-bluish spark at all four plugs. The mechanical timing is also something that you should check, as we mentioned above.

U3857 OBD-II Diagnostic Network (U) Trouble Code Description

U3857 engine trouble code is about Ignition Coil A Primary/Secondary Circuit Malfunction.

Main reason For U3857 Code

The reason of U3857 OBD-II Engine Trouble Code is Fuel Rail Pressure Sensor Circuit Malfunction.

U3857 DTC specifically refers to the camshaft (cam) timing. In this case, if the cam timing is over-retarded, the engine light will be illluminated and the code will be set.