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U3986 Engine Code Repair

Meaning of U3986 engine trouble code is a kind of network trouble code and U3986 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.

U3986 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 U3986 code is occuring now you should check U3986 repair processes.
Now don't ask yourself; What should you do with U3986 code ?
The solution is here :

U3986 Possible Solution:

U3986 Engine

The firing order is an important part of the overall design of the engine and is determined during the design of the engine to eliminate as much engine vibration as possible. If the firing order is changed or adjusted, the ignition from the spark plug is delivered at the wrong time and the engine functions poorly or does not run. The firing order for a particular engine is typically found in the repair manual specific to that model.

U3986 Code Meaning :

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

3
Ignition System Or Misfire

9
Engine Oil Temperature Sensor Malfunction

8
Cylinder 10 Contribution/balance Fault

6
Crankshaft Position Sensor B 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.

U3986 OBD-II Diagnostic Network (U) Trouble Code Description

U3986 engine trouble code is about Crankshaft Position Sensor B Circuit Malfunction.

Main reason For U3986 Code

The reason of U3986 OBD-II Engine Trouble Code is Engine Oil Temperature Sensor Malfunction.

U3986 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.