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U0503 Engine Code Repair

Meaning of U0503 engine trouble code is a kind of network trouble code and U0503 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.

U0503 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 U0503 code is occuring now you should check U0503 repair processes.
Now don't ask yourself; What should you do with U0503 code ?
The solution is here :

U0503 Possible Solution:

U0503 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.

U0503 Code Meaning :

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

0
Intake Valve Control Solenoid Circuit Low

5
O2 Sensor Heater Circuit Malfunction

0
Crankshaft Position Sensor A Circuit Malfunction

3
Glow Plug/Heater Circuit 'A' 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.

U0503 OBD-II Diagnostic Network (U) Trouble Code Description

U0503 engine trouble code is about Glow Plug/Heater Circuit 'A' Malfunction.

Main reason For U0503 Code

The reason of U0503 OBD-II Engine Trouble Code is O2 Sensor Heater Circuit Malfunction.

U0503 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.